Buying guide · GLP-1 medicines, tirzepatide and retatrutide
Protein, creatine, amino acids and electrolytes can make the habits that help protect muscle easier to keep up while you lose weight. Here's what each one is good for, who it may suit, and where the evidence stops.
In their main trials, semaglutide and tirzepatide helped people lose about 15% to 21% of their body weight on average, and retatrutide, still investigational, averaged 25% at its top dose in TRIUMPH-1.4,12,9 Some of that loss is lean tissue, including muscle. Food and strength training are the best supported ways to keep it. The right supplements can make those habits easier, especially when your appetite is small.
Affiliate links ahead. We may earn a commission; how we handle that.
At a glance
The short answer
Focus on protein, strength training, enough food, and a few targeted supplements that can make those habits easier.
Six priorities
- Prioritize proteinRoughly 80 to 120 grams a day (less if you are smaller).B studied on these medicines: partly
- Keep strength trainingTwo or three full body sessions a week, adding reps or weight over time.A studied on these medicines: partly
- Don't undereatSmall meals every three to four hours, protein first. Don't let total food intake collapse.B studied on these medicines: partly
- Consider creatine if you train3 to 5 grams a day alongside strength training.A with training · D on these medicines
- Stay hydratedSip through the day, and switch to an oral rehydration solution if vomiting or diarrhea hits.A studied on these medicines: yes
- Use amino acids only for a real needA light backup on bad stomach days, not a meal.C in short lab studies · D for extra benefit once protein is adequate
Ratings run from A (strong research) to D (not shown yet). How we rate
Our picks by need
Partner products grouped by need, not ranked. None is required. Each opens its card with the details and code.
- Protein shakeMomentous Whey Protein Isolate
- Dairy free proteinMomentous 100% Plant Protein
- Strength supportMomentous Creatine
- Hydration supportMomentous Daily Hydration
- Fuel for longer sessionsMomentous Fuel
- Light protein backupKion Aminos
- Portable protein barPRIMA Protein Bars
- Whole food protein snackMaui Nui Venison Sticks
Who this guide is for
- Taking semaglutide (Ozempic, Wegovy)
- Taking tirzepatide (Mounjaro, Zepbound) or another GLP-1 medicine
- Researching retatrutide, or in one of its trials
- Worried about muscle, strength or energy while losing weight
Before you start
- Supplements support the habits. They don't replace food, training or sleep.
- Nothing in this guide makes an unapproved retatrutide product safer.
- This is general education, not medical advice.
Important. This guide explains what current research says about keeping muscle, eating enough and staying strong while losing weight on GLP-1 medicines and related drugs. Semaglutide (as Wegovy) and tirzepatide (as Zepbound) are FDA approved for weight management.13,14 Retatrutide is not approved by the FDA, and its maker says it is legally available only to people in its clinical trials.10 Products sold online under that name are unapproved and unregulated. We do not explain how to obtain or dose any of these drugs. This is general education, not medical advice. Talk with your clinician before changing your medicine, diet, exercise or supplements.
Affiliate disclosure. Some links in this guide are affiliate links. If you buy through our links, we may earn a commission at no extra cost to you. The products we feature come from brands we partner with. We decided where each one fits from the research, and we tell you where each one's evidence stops. Our evidence ratings come from the research, not from partnerships, and no brand saw or approved this article before publication.
Researching retatrutide? Retatrutide, nicknamed "GLP-3" online, acts on three hormone receptors. When more weight comes off, more lean tissue usually comes off with it,2 so these habits are likely to matter at least as much at its level of weight loss. That is our inference: no study has yet tested any supplement, protein target or training plan in people taking it, and no supplement's safety alongside it has been studied. What follows is general nutrition and training support for large weight loss, not a retatrutide protocol, and nothing here makes an unapproved product safer. It is legally available only in clinical trials, where your study team's advice comes first, and products sold online under its name are not the medicine those trials tested.10,16 Retatrutide explained
How to read our ratings
- AStrong: high quality human research or major guidelines.
- BModerate: several relevant studies, with real limits.
- CEarly: promising but indirect or small.
- DNot shown: not supported for this claim yet.
We also tell you whether something has been studied in people on these medicines: yes, partly (observational data, or an older drug in the class) or not yet (only general research).
Quick comparison: partner supplements worth considering
None of these is required, and none replaces food, training or sleep. They're grouped by the need they serve, not ranked, and each links to our full notes, including what the research hasn't shown.
- Protein shake
- Protein snack
- Amino acids
- Strength
- Hydration
- Training fuel
Momentous Whey Protein Isolate
Complete protein in a shake
20 gprotein a scoop
- May suit
- People who find drinks easier than meals; a quick serving after training
- Main benefit
- 20 g protein, 90 calories, about 2.5 g leucine a scoop
- Evidence limits
- B with training; not tested for reducing muscle loss on these medicines
15% offEnter the code at checkout
Affiliate link
Momentous 100% Plant Protein
Dairy free complete protein
20 gprotein a scoop
- May suit
- Dairy free or plant based eaters
- Main benefit
- 20 g mostly pea protein, 130 calories a scoop
- Evidence limits
- B; pea matched whey in one study of older men; same limits as whey
15% offEnter the code at checkout
Affiliate link
Momentous Creatine
More from strength training
5 gcreatine monohydrate a scoop
- May suit
- People lifting at least twice a week, especially older adults
- Main benefit
- 5 g creatine monohydrate, NSF Certified for Sport
- Evidence limits
- A with training · D untested on these medicines; raises the creatinine blood test
15% offEnter the code at checkout
Affiliate link
Momentous Daily Hydration
Drinking enough
100 mgsodium a packet
- May suit
- People who drink more when water has flavor
- Main benefit
- Light electrolytes, 1 g sugar, 10 to 15 calories a packet
- Evidence limits
- Not a rehydration solution for vomiting or diarrhea; D for tiredness
15% offEnter the code at checkout
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Momentous Fuel
Fuel for long, hard sessions
28 gcarbohydrate a scoop
- May suit
- People training intensely for an hour or more on a small appetite
- Main benefit
- 28 g carbohydrate, 300 mg sodium a scoop
- Evidence limits
- B for carbohydrate in long exercise; unnecessary for short workouts
15% offEnter the code at checkout
Affiliate link
Kion Aminos
A light protein backup
5 gessential amino acids a scoop
- May suit
- Bad stomach days; before training when a meal is too much
- Main benefit
- 5 g essential amino acids, 2 g of them leucine
- Evidence limits
- C in short lab studies · D for extra benefit once protein is adequate; not a meal
10% offApplied automatically by our link
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PRIMA Protein Bars
Portable protein and calories
21 gprotein a bar
- May suit
- People who need a filling snack
- Main benefit
- 21 g protein, 230 to 250 calories a bar
- Evidence limits
- Collagen listed first, so less muscle building per gram than whey; 11 to 13 g added sugar; milk and egg
20% off eligible ordersEnter the code at checkout
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Maui Nui Venison Sticks
Whole food protein on the go
9 to 10 gprotein a stick
- May suit
- People who are often out
- Main benefit
- 9 to 10 g complete protein, 55 to 60 calories a stick
- Evidence limits
- A food, not a tested supplement; 290 to 380 mg sodium a stick
10% offApplied automatically by our link
Affiliate link
Affiliate links: if you buy through them, we may earn a commission. We verified each offer in October 2026 and recheck them before publishing. All our partner codes
How we chose
This is a curated selection from brands we already partner with, not an independent ranking of the whole market and not a hands on comparison. We included a partner product when it serves a need the research supports and its label shows exactly what's in it. We haven't tested these products ourselves or compared them with brands we don't work with, and other good options exist. The Momentous products carry the NSF Certified for Sport mark; the bars and venison sticks are foods.
Other supplements people ask about
Before you buy: your plan at a glance
Supplements work on top of these foundations, not instead of them. If you read nothing else, start here.
What we know, what we don't, and what you can do
- What we know. These medicines remove fat and some lean tissue. Across 20 trials, lean tissue made up about a quarter to two fifths of the weight lost, which is similar to what happens with dieting alone.2 When people diet with strength training, they lose a smaller share of lean tissue.2,33
- What we don't know. Whether any supplement protects muscle in people on these medicines specifically. Whether retatrutide spares muscle better or worse than older drugs. What happens to strength over many years of treatment.
Protein: how much you need
Protein is the raw material for muscle, and the nutrient most likely to fall short when appetite shrinks.
The joint advisory's simpler daily protein target during weight loss, with 1.2 to 1.6 g/kg for smaller adults.1
How much protein
The standard recommended daily allowance is 0.8 grams per kilogram of body weight. During active weight loss, experts have proposed 1.2 to 1.6 g/kg. Because those figures can run high in larger bodies, the same joint advisory also offers a simpler target: 80 to 120 grams a day.1 The same advisory says intake should not fall below 0.4 to 0.5 g/kg, and that prolonged intake at or above 2 g/kg should be avoided.1 Older adults generally need at least 1.0 to 1.2 g/kg, and more if they are active or unwell.23 B · studied on these medicines: partly
Higher protein has not yet been tested in a randomized trial in people on these medicines. In a small 2026 study of people starting semaglutide or tirzepatide, those who ate more protein kept more of their estimated muscle.19 One more thing matters as much as the number. The advisory states that more protein alone is "likely inadequate" to protect muscle without structured strength training.1
Protein planner
Find your weight in the table below for a daily protein range and a per meal target to discuss with your clinician or dietitian. It isn't a prescription. At 75 kg (165 lb) or more, the range is 80 to 120 grams a day, as four obesity and nutrition societies suggest. Below that, it's 1.2 to 1.6 grams per kilogram, so smaller adults are never pushed too high. If you have kidney or liver disease, have been told to limit protein, are pregnant or breastfeeding, or are under 18, don't use the table: please set your target with your care team.
| Your weight | Daily protein range | Per meal if split over three meals |
|---|---|---|
| 50 kg (110 lb) | 60 to 80 g | 20 to 27 g |
| 60 kg (132 lb) | 70 to 95 g | 23 to 32 g |
| 70 kg (154 lb) | 80 to 110 g | 27 to 37 g |
| 75 kg (165 lb) or more | 80 to 120 g | 27 to 40 g |
Which body weight to use
In a larger body, much of the extra weight is fat, which needs little protein, so multiplying all of it by 1.6 can produce targets nobody can eat on a small appetite. The advisory says using actual weight "can significantly overestimate protein requirements."1 Dietitians may use goal weight, an adjusted weight or lean mass instead. If you work with one, their number wins.
Spread it through the day
A common suggestion is about 25 to 40 grams at each meal you eat, drawn from studies in people not taking these medicines. Older muscles seem to need a slightly bigger serving to get the same building signal, roughly 0.4 g per kilogram in one study of older men.25 If you can only manage two real meals, don't worry that a big serving gets wasted. A large 100 gram dose of protein produced a bigger and longer muscle building response than 25 grams.26 Make your best meal of the day the protein heavy one.
Complete proteins, and why collagen counts for less
Dairy, eggs, meat, fish, soy and pea blends supply all the essential amino acids your muscles need. Collagen is different. In older women, whey protein raised muscle protein building and collagen did not.20 In older men, whey and pea protein both increased it, while collagen didn't.21 One 2015 trial did find collagen plus strength training helped older men,22 but the overall picture favors complete proteins. Collagen counts toward your daily total, but it does less of the muscle work per gram. B
Enough food overall
People on these medicines eat 16% to 39% fewer calories, according to studies cited by the advisory.1 Below about 1,200 calories a day for women or 1,800 for men, it becomes hard to get enough iron, calcium, magnesium, zinc and several vitamins, including B12 and D.1 The early signs of a shortfall include fatigue beyond what you'd expect, excessive hair loss, muscle weakness and unusual bruising.1
So eat less, but eat well. Build meals from protein, vegetables, fruit, whole grains and healthy fats, and aim for 21 to 25 grams of fiber a day for women or 30 to 38 grams for men.47 The advisory says a multivitamin, vitamin D, calcium or B12 "can be proactively considered", tailored to the person.1 That is a conversation for your clinician, not an automatic purchase.
Plant based and dairy free
You don't need dairy or meat to protect muscle. When total protein is adequate, plant and animal protein produce similar gains in lean mass and strength.27 Pea protein matched whey for muscle protein building in older men.21 Good options include tofu, tempeh, soy milk, edamame, lentils and pea based powders. The dairy free sample day below shows how it adds up.
Protein on retatrutide
No study has set a protein target for people taking retatrutide, so the general ranges above are the only guide available, and your trial team may set a different target. Hitting them may be harder. Average weight loss in the TRIUMPH-1 trial was larger than in the main semaglutide and tirzepatide trials, and stomach side effects were common at higher doses.9,10 That makes the protein first, small and often approach in the next chapter even more useful. If you're in a trial, your study team's dietary advice comes first.
When to set your number with a clinician
Get personal advice before raising protein if you have chronic kidney disease. Kidney guidelines suggest about 0.8 g/kg a day for later stages.24 The same applies if a clinician has told you to limit protein, if you are pregnant or breastfeeding, if you have liver disease, if you are under 18, or if you have a history of an eating disorder.
Protein shakes, bars and snacks for low appetite days
Knowing your target is one thing. Eating it when food feels like a chore is another.
Small, frequent and protein first
The advisory suggests a small breakfast followed by small meals every three to four hours, with fluids in between. Vomiting is more likely after large meals. Ginger or peppermint tea can help with nausea.1 Cool, soft foods often go down more easily than heavy ones: yogurt, cottage cheese, smoothies, soups and protein drinks.1 Eat the protein on your plate first, before you fill up. If you forget to eat, set a reminder.1
Drinkable protein
When chewing feels like too much, a shake carries a meal's worth of complete protein in a few swallows.
Best for: complete protein when chewing feels like too much
Momentous Whey Protein Isolate
Why it's here: on these medicines, protein is the nutrient most likely to fall short, and a shake is the quickest way to close the gap. One scoop covers roughly a sixth to a quarter of the 80 to 120 gram daily range in a few swallows.
Who it may suit: people who find drinks easier than food, anyone who struggles to eat protein at breakfast, and lifters who want a quick serving after training.
What's in it: 20 grams of protein and 90 calories per scoop (chocolate), with about 2.5 grams of leucine, the amino acid most linked to switching on muscle building. Grass fed whey isolate. Contains milk. NSF Certified for Sport logo on the label.P1
What the science supports: whey raises muscle protein building more than collagen in older adults,20,21 and protein plus strength training supports lean mass.28 B
What's still uncertain: whether protein powder reduces muscle loss caused by GLP-1 medicines, tirzepatide or retatrutide. No trial has tested that yet.
Do you need it? Not if food covers your protein. Greek yogurt, milk, cottage cheese and eggs do the same job for less money. The powder earns its place on the days food isn't happening.
Dairy free: Momentous 100% Plant Protein
20 grams of protein per scoop, almost entirely from pea protein, with 130 calories and 2 grams of added sugar (chocolate).P2 Pea protein matched whey for muscle protein building in a study of older men.21 A good fit if you avoid dairy or simply prefer plant protein.
Portable protein for busy or low appetite days
Best for: whole food protein in your pocket
Maui Nui Venison Sticks
Why it's here: it's real meat, so it counts as complete protein, and it travels in a pocket or bag.
Who it may suit: people who are often out, who can face a few bites but not a meal, or who want something savory before training.
What's in it: each 28 gram stick has 9 to 10 grams of complete protein for 55 to 60 calories: the Original has 9 grams, the Peppered 10.P8 Sodium runs about 290 to 380 milligrams a stick, which matters if you've been told to limit salt.P8
Worth knowing: no study has tested venison sticks for muscle; they count simply as protein food. A boiled egg, a cheese stick or a tuna pouch can do the same job for less.
Best for: a filling, portable snack when a meal won't happen
PRIMA Ancestral Protein Bars
Why it's here: when a plate feels like too much, a bar delivers protein and calories you might otherwise miss, and it keeps in a bag for days.
Who it may suit: people who want something chewable and a little sweet, and anyone at risk of eating too little overall.
What's in it: every current PRIMA flavor has 21 grams of protein in a 57 gram bar, with 230 to 250 calories and 11 to 13 grams of added sugar, from honey and, in some flavors, coconut sugar or nectar.P7 All flavors contain milk and egg, Peanut Butter contains peanuts, and Mocha has 25 milligrams of caffeine.P7
One detail that matters for muscle: the protein blend lists grass fed collagen first and whey second, and collagen builds muscle less effectively than whey.20,21 So treat a bar as a convenient protein and energy boost, not as 21 grams of complete muscle building protein. Pair it with yogurt or milk when you can.
Two sample days
Here is what about 100 grams of protein can look like in small, manageable portions. Protein values are approximate, from USDA food data and product labels.53 These are examples, not prescriptions. Adjust for allergies, medical conditions and your own target.
Regular day
Dairy free day
PRIMA bars contain milk and egg, so they are not dairy free.
Nausea, constipation and food aversions
Stomach side effects are most likely in the first weeks and after dose increases. They can be strong on retatrutide too: at its top dose in TRIUMPH-1, 42% of people had nausea and 25% vomiting, against 15% and 5% on placebo.10 In the first days of treatment, smaller meals and avoiding fatty or very high fiber foods can help.1 Once your stomach settles, fiber from food plus steady fluids helps with constipation.1 If meat suddenly puts you off, switch protein sources rather than dropping protein: eggs, dairy, tofu and shakes are all fair game. If nausea keeps getting in the way of eating, ask your clinician about treatment. Some anti nausea medicines can worsen constipation, so the choice matters.1
Essential amino acids: a light backup
Essential amino acids (EAAs) are the nine protein building blocks your body can't make. EAA supplements deliver them without the rest of a meal, which makes them light on a bad stomach day. They don't replace protein: a scoop contains far less than a real serving, and branched chain amino acids (BCAAs) alone don't do the job.29
Short lab studies show EAAs can switch on muscle protein building, including during calorie restriction.30 C What hasn't been shown is extra benefit once your total protein intake is already adequate. D A trial of a medical nutrition product in people on GLP-1 medicines is still recruiting.54
Best for: days when food and shakes both feel like too much
Kion Aminos (essential amino acids)
Why it's here: essential amino acids are the building blocks muscle needs, in a light drink with no meal attached.
Who it may suit: people on a bad stomach day, or anyone who wants something light before training when a meal feels like too much.
What's in it: 5 grams of essential amino acids per scoop, 2 grams of them leucine, sweetened with stevia (plus monk fruit in some flavors).P6
What the science supports: short lab studies show EAAs switch on muscle protein building.30 C What's still uncertain: any extra benefit once your total protein is adequate. D
What it isn't: a substitute for meals or complete protein. A scoop of whey delivers more than twice the essential amino acids (about 11 grams), along with the rest of the protein your body uses.P1
Do you need it? Not if you're reaching your protein range. It's a backup for the hard days.
Creatine: more from your strength training
Creatine is one of the most researched sports supplements. Here's what it does well, and what it hasn't been shown to do on these medicines. It works alongside the routine in the strength training chapter, not instead of it.
What creatine does
Creatine tops up the fast energy system your muscles use for short, hard efforts like lifting. Supplementing raises muscle creatine stores by roughly 20% to 40%.36 In older adults doing resistance training, creatine added about 1.4 kg of lean tissue and modest strength gains compared with training alone.35 A · with training
What has not been shown in people on these medicines
No published randomized trial has yet tested creatine during GLP-1 medicine weight loss, a point a 2026 review in Clinical Nutrition makes explicitly.39 One small trial is recruiting. It gives 10 grams a day or a placebo to 40 people on GLP-1 medicines during 12 weeks of strength training, with results expected after May 2027.40 Nothing has been published on creatine with retatrutide. Until then, creatine's possible benefit here is an inference from training research, not a proven way to prevent medication related muscle loss. D · studied on these medicines: not yet
How people use it
The usual dose is 3 to 5 grams a day. A loading week is optional; without it, muscles fill up over three to four weeks.36,37 Expect the scale to rise a little at first. Loading in particular can hold about 0.5 to 1 liter of extra water,36 which is water, not fat, and not a sign your medicine has stopped working. Creatine helps most when paired with training.35
Who should ask first
Creatine can raise creatinine on a blood test, because creatinine is what creatine breaks down into. That can look like a kidney problem when it isn't. In a three month trial, cystatin C, a kidney marker unaffected by creatine, stayed normal.37,38 Tell your clinician you take it, especially since kidney function is already monitored on these medicines when fluids run low.13,14 If you have kidney disease, don't start creatine without your kidney specialist.
Best for: people who strength train at least twice a week
Momentous Creatine
Why it's here: strength training is your main tool for keeping muscle, and in general research, creatine is the supplement with the strongest evidence for adding strength and lean tissue to that training. That research wasn't done in people on these medicines.
Who it may suit: people lifting or doing resistance work at least twice a week, especially older adults, who were the focus of the strongest trials.
What's in it: 5 grams of creatine monohydrate per scoop and nothing else, 90 servings per tub. NSF Certified for Sport.P3
What the science supports: more lean tissue and strength when combined with resistance training, in older adults.35 A
What's still uncertain: whether creatine reduces muscle loss caused by semaglutide, tirzepatide or retatrutide. No published trial has tested it, and the first small trial reports after May 2027.40 D
Practical notes: one scoop a day in water, at any time. Expect a small early bump on the scale from water. Tell your clinician you take it, because it can raise the creatinine blood test. Skip it if you have kidney disease, unless your kidney specialist agrees.
Do you need it? No. It's optional, and worth considering if you train.
Electrolytes and hydration: when they help and when they don't
Fluids matter more on these medicines than most people realize. Electrolyte packets matter less than the marketing suggests.
Everyday fluids
Both the Wegovy and Zepbound labels warn about kidney injury from dehydration, mostly after nausea, vomiting or diarrhea.13,14 Their patient guides ask you to drink fluids and to tell your clinician about stomach symptoms that won't go away. The Obesity Society's guidance suggests more than 2 to 3 liters a day,47 though needs vary with body size, heat and activity, and that figure doesn't apply if your clinician has limited your fluids, for example for heart failure or kidney disease. For most people, water plus normal meals covers it.
Sweaty training and long sessions
Electrolyte drinks earn their place in two situations: when flavor helps you drink more than plain water would, and in long, sweaty sessions where you lose sodium and need fuel.
Best for: people who drink more when water has some flavor
Momentous Daily Hydration
Why it's here: dehydration is the main risk the medicine labels warn about, as the section above explains. If a little flavor helps you finish another glass, that is a practical win.
Who it may suit: people who find plain water hard to keep drinking, and people who sweat during everyday training.
What's in it: per packet, 100 mg sodium, 50 mg potassium and 150 mg chloride, 1 gram of sugar and 10 to 15 calories. Mixed into 16 oz of water, as directed. No magnesium. NSF Certified for Sport.P4
What the science supports: staying hydrated matters on these medicines.13,14 A The product itself hasn't been studied in people taking them.
What it isn't: a rehydration solution for vomiting or diarrhea. Mixed as directed, it has about 9 mmol of sodium per liter, against 75 in a medical oral rehydration solution.45 Nor is it a fatigue fix. D
Do you need it? No. Water works. It's a convenience if it helps you drink more.
Best for: intense sessions longer than an hour
Momentous Fuel
A sports drink mix for intense exercise lasting 60 minutes or more. Each scoop has 28 grams of carbohydrate (from isomaltulose and fructose) plus 300 mg sodium, 150 mg potassium and 100 mg magnesium, with no caffeine.P5 It's useful when you are training long and hard on a small appetite and need fuel you can drink. Sports nutrition guidance supports carbohydrate during prolonged exercise.41 B It's unnecessary for a 30 minute lift or a walk.
Ordinary hydration, sports drinks and medical rehydration
Sodium per liter
Vomiting or diarrhea: rehydration solution first
When you are losing fluid through your gut, reach for an oral rehydration solution from a pharmacy. It's built to the WHO formula, with the sodium and glucose balance your gut needs to absorb water.45 Sports drinks and daily electrolyte packets are not designed for this. If you're in a retatrutide trial, where vomiting affected a quarter of people on the top dose, ask your study team what to keep at home.10 Seek care for diarrhea lasting more than two days, six or more loose stools a day, signs of dehydration such as extreme thirst, little or dark urine, dizziness or tiredness, black or bloody stools, or severe pain.46
Who should be careful with electrolytes
Extra sodium isn't right for everyone with heart failure, high blood pressure or kidney disease. Extra potassium can be dangerous with ACE inhibitors, ARBs, spironolactone or kidney disease. Those medicine labels warn that potassium supplements or salt substitutes can raise blood potassium.48,49 If any of these apply, ask before using electrolyte products.
Strength training: what makes protein and creatine work
If protein is the raw material, strength training is the instruction. Of everything in this guide, it has the strongest evidence for keeping muscle while losing weight.
The minimum plan experts recommend
The World Health Organization recommends muscle strengthening on at least two days a week, and three or more days of balance and strength work for older adults.32 The American College of Sports Medicine's 2026 review of 137 systematic reviews found strength improves with two to three sets of challenging loads, done at least twice a week, while more weekly sets help muscles grow.31 For people on GLP-1 medicines, the joint advisory aims for strength training at least three times a week plus at least 150 minutes of moderate cardio.1 A
The World Health Organization's minimum for muscle strengthening.32
The joint advisory's strength aim on GLP-1 medicines.1
Does it work during weight loss? In a trial of 160 older adults with obesity who were dieting, lean mass fell by about 2% to 3% in the groups that did strength training, compared with about 5% with aerobic exercise alone. Strength rose by 18% to 19%.33 Exercise has also been tested alongside liraglutide, an older GLP-1 medicine, where the combination cut body fat about twice as much as either one alone.34 Trials pairing structured strength training with semaglutide or tirzepatide are under way.55 None has been reported with retatrutide, so its users rely on the same weight loss research for now. B · studied on these medicines: partly
A sample week
That gives you three strength sessions and about 150 minutes of easy to moderate movement. If three sessions is too much right now, two still counts.
Progress gradually
Write down what you lift. When a set feels comfortably easy, add a rep or two next time. Once you reach the top of your rep range, add a little weight. Slow, boring progress is the goal. Experienced lifters: your job during weight loss is to keep lifting heavy enough to tell your body the muscle is still needed.
Training through nausea, low intake and dose increases
On rough days, shorten the session rather than skipping it: one set of each exercise, or a brisk walk. Try to eat something with carbohydrate and protein a few hours before you train, like a banana with yogurt.41 Skip hard training while you are vomiting, have diarrhea or feel dizzy. Dehydration and exercise are a poor mix, and dehydration is the main trigger for the kidney problems these labels warn about.13,14
Check with your clinician first if…
…you have heart disease, chest pain, fainting spells, uncontrolled blood pressure, recent surgery, joint problems or a history of falls. Also ask first if you take insulin or a sulfonylurea. Exercise lowers blood sugar, and these medicines already raise the risk of lows when combined with them.13,14 A physical therapist or qualified trainer can adapt every exercise above.
Energy and fatigue: why you feel drained, and what helps
Feeling flat, heavy legged or foggy is a common complaint on these medicines. Tiredness can have several causes at once. Some you can change, some need your clinician, and sometimes no clear cause is found.
Tiredness is common, and worth looking into
Fatigue appears on the labels. In trials, 11% of people on Wegovy 2.4 mg reported fatigue or weakness, compared with 5% on placebo.13 On Zepbound the figures were 5% to 7%, against 3% on placebo.14 That means most people don't feel it, and among those who do, the medicine isn't always the only reason. The list below covers possible contributors worth checking with your clinician. Side effects in general are most likely in the first weeks and after dose increases,1 so note whether your tiredness follows that pattern and share it with your clinician. If you're in a retatrutide trial, report tiredness to your study team: that is how side effects get recorded, and the causes below still apply.
Fatigue reported in the trials
Eat enough energy, not just less
This is one of the first things to check. Appetite suppression can push intake far lower than you would choose deliberately, and calories have been reported to fall by 16% to 39%.1 Combine that with training, and you can end up in what sports scientists call low energy availability: too little fuel left for normal body functions once exercise is paid for. In athletes, it shows up as fatigue, stalled strength, poor recovery, low mood and more injuries.42 If your workouts feel harder every week, your lifts are going backwards and you feel cold or irritable, undereating is one possible cause worth ruling out. Eat something at regular times even when you are not hungry, and don't push for the fastest possible loss.
Carbohydrates around training
Protein gets the attention, but carbohydrate fuels hard training. Sports nutrition guidance matches carbohydrate to how much and how hard you train, and recommends a carbohydrate and protein snack before a session.41 You don't need large amounts. A banana, toast, rice or fruit with yogurt before lifting can turn a flat session into a productive one. Very low carbohydrate eating plus intense exercise on a medicine that already cuts appetite is a recipe for running on empty. If you do long sessions of an hour or more, the hydration chapter covers drinkable fuel.
Protein, recovery and training load
If you feel wrecked for days after a session, do fewer sets, keep the intensity, and make sure training days include a protein rich meal. Training more to "burn more" usually backfires when food intake is low.
Fluids and stomach upsets
Even mild dehydration can feel like fatigue, dizziness or a headache. The hydration chapter covers what to drink and when to get help.
Sleep
Adults need seven or more hours of sleep a night for health.43 Poor sleep makes everything above worse: training feels harder, appetite signals get messier and recovery slows. Our sleep guide covers how to protect it.
Sleep medicine's consensus minimum for adults.43
Nutrients worth checking
Some shortfalls feel exactly like medicine fatigue. Ask your clinician whether checks make sense for:
- Vitamin B12, especially if you also take metformin. Its label reports that B12 dropped below normal in about 7% of patients, and advises B12 checks every 2 to 3 years.44
- Iron, especially with heavy periods or a plant based diet. Test before you supplement, because iron isn't harmless if you don't need it.
- Vitamin D and other nutrients the advisory lists as at risk when intake is low.1
When the medicine itself plays a part
Some effects come directly from the medicine. Blood pressure can fall: on Zepbound, low blood pressure occurred in 1.6% of people versus 0.1% on placebo, which can show up as dizziness when you stand.14 In TRIUMPH-2, a retatrutide trial in people with type 2 diabetes, low blood pressure was reported in 6% of people on the top dose, against under 1% on placebo.56 If you also take insulin or a sulfonylurea, the risk of low blood sugar rises, and your clinician may need to lower those doses.13,14 Shakiness, sweating, confusion or a racing heart need prompt attention.
What you can adjust yourself
- Eat something small every three to four hours, protein first
- Add carbohydrate before training
- Sip fluids through the day
- Keep meals lighter around dose increases
- Stand up slowly
- Do shorter sessions rather than none
- Protect seven or more hours of sleep
- Track energy alongside your dose schedule
What to ask your clinician about
- Tiredness lasting more than a few weeks at a stable dose
- Dizziness when standing, especially on blood pressure medicines
- Hair loss, brittle nails or easy bruising
- B12 (if on metformin), iron or vitamin D testing
- Insulin or sulfonylurea doses
- Strength falling despite training and protein
- Starting creatine, potassium or magnesium supplements
Anything severe or sudden belongs in the warning signs chapter. Don't wait it out.
The research: what “losing muscle” on these medicines really means
Headlines about "Ozempic muscle loss" skip two details: what the scans actually measure, and what happens with any big weight loss.
Lean mass is not the same as muscle
Most trials use a DXA scan, which divides your body into fat, bone and everything else. That everything else is called lean mass, and it includes muscle, but also water, organs, stored carbohydrate and connective tissue.1,52 Muscle is roughly half of it, although that ratio is debated.1,52 So when a study reports a drop in lean mass, some of it is muscle and some of it is not.
What the trials found
- Semaglutide 2.4 mg (Wegovy). In the STEP 1 trial's scan group, people lost about 9.3 kg of fat and 5.8 kg of lean mass over 68 weeks, so lean tissue was about 38% of the tissue lost.3
- Tirzepatide (Zepbound). In SURMOUNT-1, people lost about 15.9 kg of fat and 5.6 kg of lean mass over 72 weeks, or about 26% lean.5
- All incretin trials together. A 2026 analysis of 20 randomized trials found lean tissue was about 35% of weight lost with semaglutide, 25% with tirzepatide and 26% with lifestyle programs. Lifestyle programs that included resistance training came in lowest, at about 18%.2
- Retatrutide. Only one study has scanned body composition so far: a phase 2 study in people with type 2 diabetes. Fat mass fell by 23% to 26% on the higher doses, and the share of lean mass lost looked similar to other obesity treatments.8 The phase 3 results published so far report weight, not muscle.9,56 More below
Fat and lean mass lost in the scan groups
Fat lostLean mass lost
These numbers come from different trials with different people, so they are not a head to head ranking of the drugs. The Wegovy label puts it plainly: semaglutide lowers body weight "with greater fat mass loss than lean mass loss."13
Lean share of weight lost
Why strength and daily function matter as much as the scan
What you notice day to day is strength: getting out of a chair, carrying shopping, climbing stairs. Small MRI studies are reassuring. With tirzepatide, the thigh muscle that remained carried less fat,6 and with semaglutide 7.2 mg, sit to stand performance held up over 72 weeks.7
Who should take extra care
A joint advisory from four obesity and nutrition societies lists the people most at risk of losing too much muscle: older adults, women around menopause, people with low testosterone, anyone inactive or not strength training, people eating little protein, and people with a history of losing and regaining weight.1 If that describes you, the protein, creatine and strength training chapters matter even more.
Track your progress beyond the scale
The scale can't tell you whether you're getting weaker. These three checks give you a better picture.
Why the scale and smart scales mislead
Bathroom "body composition" scales estimate lean mass from how easily a small current passes through you, which shifts with hydration.52 These medicines change how much you eat and drink, and creatine adds water, so those numbers can swing for reasons that have nothing to do with muscle. The joint advisory recommends checking strength and function itself, with tests like sit to stand and stair climbing.1
The monthly strength check
Monthly strength check
Do these checks at the start (or as soon as you can), then every four weeks, at the same time of day and not within two days of a dose increase or a hard workout.
- 30 second chair stand. Use a sturdy chair without arms, about 17 inches high. For safety, push it against a wall. Sit in the middle with your feet flat and your arms crossed at the wrists against your chest. On "go," stand all the way up and sit back down as many times as you can in 30 seconds. Count the full stands. Have someone nearby if your balance is unsteady, and stop if you need your arms.50
- One benchmark lift. Choose one exercise from your routine, like goblet squats, push ups or rows. Use the same weight each time and record how many good reps you can do. This matters most for younger or fitter people, because chair stands change little for them.1
- One flight of stairs. Time it, or rate how easy it felt from 1 to 5.
Also rate your energy and recovery from 1 to 5. If you own a grip gauge, you can add grip strength.
Your log · example data, not a real person's results
| Check | Chair stands (30 s) | Benchmark lift (reps) | Stairs (1 to 5) | Energy (1 to 5) |
|---|---|---|---|---|
| Week 0 | 12 | 10 | 3 | 3 |
| Week 4 | 13 | 11 | 4 | 3 |
| Week 8 | 13 | 11 | 4 | 4 |
Reading your results: steady or rising numbers are a good sign that your strength is holding up, though they can't show exactly how much muscle you have. If your numbers fall at two checks in a row despite training and eating enough protein, look again at your food and training, and mention it to your clinician. This is your own trend over time. It is not a test for muscle loss or any medical condition.
What to do with your results
Bring your log to appointments. A slide in strength alongside fast weight loss is a useful prompt to talk about protein, training or the pace of your treatment.
Symptoms that need medical attention
Get medical help promptly for:
- Severe stomach pain that won't go away, with or without pain spreading to your back13,14
- Vomiting or diarrhea that won't stop, very little urine, dizziness, confusion or fainting13,14,46
- Pain in the upper right belly with fever, yellowing skin or eyes, or pale stools13,14
- Signs of low blood sugar that don't improve with treatment13,14
- Swelling of the face, lips or throat, or trouble breathing13,14
- Sudden loss of vision51
- Thoughts of harming yourself
Call your clinician soon about: tiredness lasting weeks, dizziness when standing, hair loss or easy bruising, strength dropping at two checks in a row, or constipation lasting several days.
If you use a product that isn't an approved medicine, the same warning signs apply. Tell the clinician exactly what you have been taking.
How the medicines differ: single, dual and triple agonists
All of these medicines mimic gut hormones that shape appetite and blood sugar. The difference is how many hormone receptors each one activates. The habits in this guide apply to all of them. What changes is how much we know about their effects on muscle.
Semaglutide and other GLP-1 medicines
Semaglutide activates one receptor, GLP-1. It is sold as Wegovy for weight management (an injection and now a daily tablet) and as Ozempic for type 2 diabetes.13 In the STEP 1 trial, people lost an average of 14.9% of their body weight over 68 weeks, compared with 2.4% on placebo.4 Other GLP-1 medicines include liraglutide (Saxenda) and orforglipron (Foundayo), a daily pill approved in 2026.15
Tirzepatide, a dual agonist
Tirzepatide activates two receptors, GIP and GLP-1. It is often called "a GLP-1," but it is more precisely a dual agonist. It is sold as Zepbound for weight management and Mounjaro for type 2 diabetes.14 In SURMOUNT-1, the highest dose produced an average weight loss of 20.9% over 72 weeks, against 3.1% on placebo.12
Retatrutide, the triple agonist
What it is. Retatrutide is a single molecule that activates three receptors: GIP, GLP-1 and glucagon.9 The glucagon part is what's new. Researchers are still working out exactly what it adds beyond the other two.
What the trials measured. In TRIUMPH-1, 2,339 adults with obesity took retatrutide or placebo for 80 weeks. Counting everyone who started, average weight loss was 17.6%, 23.7% and 25.0% on the three doses, against 3.9% on placebo.9 Lilly reports higher figures for people who stayed on treatment.10 The most common side effects were digestive. At the top dose, 42% of people had nausea and 25% vomiting, compared with 15% and 5% on placebo. Dysesthesia, an unusual skin sensation, occurred in 5% to 12.5% of people versus 0.9% on placebo.10 A second phase 3 trial, TRIUMPH-2, enrolled 1,152 adults with obesity and type 2 diabetes. Average weight loss at 80 weeks was 11.9%, 16.8% and 18.8% on the three doses, against 5.1% on placebo, and low blood pressure and dysesthesia were more common than on placebo.56
What we know about muscle. Very little so far. Retatrutide's effect on body composition has been measured in one phase 2 study of people with type 2 diabetes. Among the 103 people who finished it with both scans, fat mass fell by 23% to 26% on the higher doses over 36 weeks. The authors describe the share of lean mass lost as similar to other obesity treatments.8 The large phase 3 results published so far report weight, not muscle.9,10,56 D for any claim that retatrutide preserves muscle
Why approved drug evidence doesn't automatically apply. Retatrutide acts on a different set of receptors, produces larger weight losses and has its own side effect pattern. Findings about semaglutide or tirzepatide and muscle can't simply be copied across. What does carry over are the fundamentals: protein, strength training, fluids and sleep support muscle during any large weight loss.
Where it stands. Retatrutide is investigational and not approved by the FDA. Lilly says it is "legally available only to participants in Lilly's clinical trials"10 and plans to apply for FDA approval in the first quarter of 2027.11 The FDA states that retatrutide cannot be used in compounding.16
If you're in a retatrutide trial. Your study team monitors you closely, and their advice comes first. It's reasonable to ask them whether body composition is being measured, how much protein they recommend, and whether strength training fits the protocol. The monthly strength check in this guide gives you a simple log to bring along.
For a fuller comparison of the two medicines, see our guide to semaglutide vs retatrutide.
What “GLP-3” means
You'll see retatrutide called "GLP-3" online. It's a nickname, not a scientific category. There is no GLP-3 receptor or drug class. The name is shorthand for adding a third receptor, glucagon, to the two that tirzepatide targets. When you research retatrutide, search for its real name, and be wary of anything sold simply as "GLP-3."
Semaglutide (Wegovy)
ApprovedTirzepatide (Zepbound)
ApprovedDifferent trials with different people. Read across rows, not as a ranking.
Unapproved and online products: what the research can't tell you
Some readers are already using products bought online, sometimes labelled "for research use only." We won't lecture you, and we won't help you source anything. Here is what the evidence can and can't tell you.
A trial medicine and an online vial are not the same thing
Every trial result in this guide comes from medicine made to pharmaceutical standards, given at known doses, with participants closely monitored. None of that applies to a vial bought online. The FDA has warned companies selling semaglutide, tirzepatide, retatrutide and similar compounds labelled "for research purposes" or "not for human consumption."16 In one 2026 warning letter, the FDA found that a "research use only" seller's own marketing showed the products were intended for people.17
What independent testing has found
When researchers bought semaglutide from illegal online sellers, the vials that arrived were 7.7% to 14.4% pure, against the 99% claimed. Every sample contained bacterial endotoxin, and orders for pens were never delivered.18 That study tested semaglutide, not retatrutide, but it shows why a trial result tells you nothing about a product's contents.
Why food and supplements don't remove those risks
Protein, creatine, electrolytes or amino acids can support your body during weight loss. They can't change what's in a vial, correct a wrong dose or remove contamination.
If you already use one
Tell a clinician what you're taking, ideally with the product in hand, so they can monitor you properly. Learn the warning signs. Everything in the practical chapters of this guide still applies to you.
Frequently asked questions
Which supplements should I take, or avoid, on a GLP-1 or retatrutide?
None is required. If you want help reaching your protein target or getting more from training, protein powder and creatine have the strongest support, with essential amino acids and electrolytes as situational extras.28,35 Vitamins such as B12 and D are worth checking with your clinician rather than guessing.1 Skip BCAA drinks, and ask before taking potassium if you use ACE inhibitors, ARBs or spironolactone.29,48,49 No supplement has been studied in people taking retatrutide, so neither its benefit nor its safety alongside it is known. See the quick comparison
Is muscle loss on Ozempic reversible?
Do I lose less muscle on tirzepatide than on semaglutide?
Pooled data show a lower lean share with tirzepatide (about 25%) than semaglutide (about 35%), but from different trials and people.2 No head to head trial has compared them on muscle.
Does retatrutide preserve muscle?
Nobody knows yet. The only body composition data come from one phase 2 study in people with type 2 diabetes, where the share of lean mass lost looked similar to other treatments.8 Retatrutide is not approved.
How can I keep muscle on retatrutide?
No method has been tested in people taking retatrutide. The general approaches for any large weight loss are protein at every meal, strength training two or three times a week, enough total food, fluids and sleep;1 whether they work the same way with retatrutide is unknown. It is legally available only in clinical trials, where your study team's advice comes first.10
How much protein should I eat on Zepbound, Wegovy or retatrutide?
Four obesity and nutrition societies suggest roughly 80 to 120 grams a day, or 1.2 to 1.6 g/kg, with smaller adults at the lower end.1 No study has set a separate target for retatrutide, so the same range is the starting point. If you have kidney disease, set your target with your care team.24 Find your range
Can I take creatine with tirzepatide or retatrutide?
Neither the Zepbound nor the Wegovy label lists creatine as an interaction, and no published trial has tested creatine alongside these medicines yet.13,14,39 Its benefits alongside strength training are well studied in general, but whether they hold on these medicines hasn't been tested. Tell your clinician, because it can raise the creatinine blood test. Retatrutide is investigational, so its combination with anything is untested. Our notes on Momentous Creatine
Should I take essential amino acids on a GLP-1?
Only as a backup. Complete protein from food or a shake comes first. EAAs can help on days you can't manage either, but they haven't been shown to add benefit once your protein intake is adequate.29,30 Our notes on Kion Aminos
Do I need electrolytes on a GLP-1?
Most people don't need daily packets; water and regular meals cover it. They can help if they make you drink more or you sweat heavily. For vomiting or diarrhea, use an oral rehydration solution, and seek care if it doesn't settle.45,46 Our notes on Momentous Daily Hydration
Why am I so tired on tirzepatide?
Fatigue is a listed side effect (5% to 7% vs 3% on placebo),14 and other possible contributors include eating too little, too little carbohydrate around training, dehydration and poor sleep. See the energy chapter. If it lasts weeks, talk to your clinician.
Sources and how we rated the evidence
We rate each recommendation from A to D and say whether it has been studied in people on these medicines. We favor clinical trials, systematic reviews, professional guidelines and official drug labels, and we link every key number to its source below. Product facts come from each brand's current label and page, checked on the date shown.
Medical review pending This guide has not yet been reviewed by an independent clinician. A review line will appear here once a review is complete.
We review this guide every three months, and sooner when major trial results, approvals or label changes arrive.
Complete source list
Sources cited in the article
Numbers match the citations in the article. "P" sources are product facts read from current brand labels and pages on 29 Oct 2026.
- Mozaffarian D, et al. Nutritional priorities to support GLP-1 therapy for obesity: a joint Advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society. Obesity 2025;33:1475. PMC12304835
- Eisa N, Barood O, et al. Lean mass changes with incretin therapy versus lifestyle intervention: systematic review and meta-analysis of randomised controlled trials. Diabetes Obes Metab 2026;28:4818. PubMed 41877354
- STEP 1 (NCT03548935) results, body composition outcomes (DXA, semaglutide 2.4 mg n=83, placebo n=39). ClinicalTrials.gov. link
- Wilding JPH, et al. Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med 2021;384:989. PubMed 33567185
- Look M, et al. Body composition changes during weight reduction with tirzepatide in the SURMOUNT-1 study. Diabetes Obes Metab 2025. PMC11965027
- Sattar N, et al. Tirzepatide and muscle composition changes in people with type 2 diabetes (SURPASS-3 MRI). Lancet Diabetes Endocrinol 2025. PubMed 40318682
- Hjelmesæth J, et al. Effect of semaglutide on thigh skeletal muscle volume, fat infiltration and physical function (STEP UP MRI). Diabetes Obes Metab 2026. PubMed 42764399
- Coskun T, et al. Effects of retatrutide on body composition in people with type 2 diabetes: a substudy of a phase 2 trial. Lancet Diabetes Endocrinol 2025;13:674. PubMed 40609566
- Jastreboff AM, et al. Retatrutide, a triple hormone receptor agonist, for treatment of obesity (TRIUMPH-1). N Engl J Med, published online 29 Sep 2026. PubMed 42814954
- Eli Lilly and Company. Lilly's triple agonist, retatrutide, delivered powerful weight loss in pivotal Phase 3 obesity trial. Press release, 21 May 2026. link
- Eli Lilly and Company. Retatrutide successful in two additional Phase 3 obesity trials. Press release, 23 Jul 2026. link
- Jastreboff AM, et al. Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1). N Engl J Med 2022;387:205. PubMed 35658024
- WEGOVY (semaglutide) injection and tablet, prescribing information and medication guide, revised 06/2026. DailyMed. link
- ZEPBOUND (tirzepatide) prescribing information and medication guide, revised 08/2026. DailyMed. link
- FOUNDAYO (orforglipron) prescribing information. DailyMed. link
- US Food and Drug Administration. FDA's concerns with unapproved GLP-1 drugs used for weight loss. Content current as of 1 Oct 2026. link
- US Food and Drug Administration. Warning letter to Gram Peptides, 31 Mar 2026. link
- Ashraf AR, et al. Multifactor quality and safety analysis of semaglutide products sold by online sellers without a prescription. J Med Internet Res 2024. PubMed 39509151
- Babazadeh D, Therrien S, Fitch AK, et al. Changes in food cravings, dietary quality, body composition, and dietary intake during GLP-1 receptor agonist therapy: the CRAVE study. Obes Pillars 2026;19:100292. PubMed 42440974
- Oikawa SY, et al. Whey protein but not collagen peptides stimulate acute and longer-term muscle protein synthesis with and without resistance exercise in healthy older women. Am J Clin Nutr 2020;111:708. PubMed 31919527
- McKendry J, et al. The effects of whey, pea, and collagen protein supplementation beyond the recommended dietary allowance on integrated myofibrillar protein synthesis in older adults. Am J Clin Nutr 2024;120:34. PubMed 38762187
- Zdzieblik D, et al. Collagen peptide supplementation in combination with resistance training improves body composition and increases muscle strength in elderly sarcopenic men: a randomised controlled trial. Br J Nutr 2015. PubMed 26353786
- Bauer J, et al. Evidence-based recommendations for optimal dietary protein intake in older people (PROT-AGE). J Am Med Dir Assoc 2013;14:542. PubMed 23867520
- KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int 2024. doi
- Moore DR, et al. Protein ingestion to stimulate myofibrillar protein synthesis requires greater relative protein intakes in healthy older versus younger men. J Gerontol A 2015. PubMed 25056502
- Trommelen J, et al. The anabolic response to protein ingestion during recovery from exercise has no upper limit in magnitude and duration in vivo in humans. Cell Rep Med 2023. PMC10772463
- Lim MT, et al. Animal protein versus plant protein in supporting lean mass and muscle strength: a systematic review and meta-analysis of randomized controlled trials. Nutrients 2021. PMC7926405
- Morton RW, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med 2018;52:376. PMC5867436
- Wolfe RR. Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? J Int Soc Sports Nutr 2017. PMC5568273
- Gwin JA, et al. Essential amino acid-enriched whey enhances post-exercise whole-body protein balance during energy deficit more than iso-nitrogenous whey or a mixed-macronutrient meal: a randomized, crossover study. J Int Soc Sports Nutr 2021. PMC7791816
- Currier BS, et al. American College of Sports Medicine Position Stand. Resistance training prescription for muscle function, hypertrophy, and physical performance in healthy adults: an overview of reviews. Med Sci Sports Exerc 2026;58:851. doi
- Bull FC, et al. World Health Organization 2020 guidelines on physical activity and sedentary behaviour. Br J Sports Med 2020. PMC7719906
- Villareal DT, et al. Aerobic or resistance exercise, or both, in dieting obese older adults. N Engl J Med 2017;376:1943. PMC5552187
- Lundgren JR, et al. Healthy weight loss maintenance with exercise, liraglutide, or both combined. N Engl J Med 2021. doi
- Chilibeck PD, et al. Effect of creatine supplementation during resistance training on lean tissue mass and muscular strength in older adults: a meta-analysis. Open Access J Sports Med 2017;8:213. PMC5679696
- Kreider RB, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr 2017;14:18. PMC5469049
- Antonio J, et al. Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show? J Int Soc Sports Nutr 2021;18:13. PMC7871530
- Gualano B, et al. Effects of creatine supplementation on renal function: a randomized, double-blind, placebo-controlled clinical trial. Eur J Appl Physiol 2008. PubMed 18188581
- Ostojic SM, Galyean S. Creatine for glucagon-like peptide-1-associated muscle loss. Clin Nutr 2026;66:106805 (authors disclose creatine industry ties). PubMed 42800365
- Creatine Supplementation During GLP-1a Therapy (NCT07625202), University of Saskatchewan, recruiting; primary completion estimated May 2027. link
- Thomas DT, Erdman KA, Burke LM. American College of Sports Medicine Joint Position Statement: Nutrition and Athletic Performance. Med Sci Sports Exerc 2016. PubMed 26891166
- Mountjoy M, et al. 2023 International Olympic Committee's consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med 2023. PubMed 37752011
- Consensus Conference Panel (Watson NF, et al.). Recommended amount of sleep for a healthy adult: a joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society. J Clin Sleep Med 2015. PubMed 25979105
- Metformin hydrochloride tablets, prescribing information, section 5.2 Vitamin B12 deficiency. DailyMed. link
- World Health Organization and UNICEF. Reduced osmolarity oral rehydration salts formulation. link
- National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms and causes of diarrhea. link
- The Obesity Society. Experts develop nutritional recommendations for patients treated with anti-obesity medications (summary of Almandoz JP, et al. Obesity 2024;32:1613), 10 Jun 2024. link · paper
- Lisinopril tablets, prescribing information (potassium interactions). DailyMed. link
- Spironolactone tablets, prescribing information (hyperkalemia). DailyMed. link
- Centers for Disease Control and Prevention, STEADI. Assessment: 30-Second Chair Stand. PDF
- European Medicines Agency. PRAC concludes eye condition NAION is a very rare side effect of semaglutide medicines, Jun 2025. link
- Bolte J, Smelter AA, Norton L. Are we giving too much weight to lean mass loss? Mol Metab 2025. PMC12506580
- USDA FoodData Central, SR Legacy, protein per 100 g: Greek yogurt plain nonfat 9.5 g (fdcId 171312); chicken breast roasted 31.0 g (171477); Atlantic salmon farmed cooked 22.1 g (175168); cottage cheese 2% 10.4 g (172182); firm tofu 17.3 g (172475); lentils boiled 9.0 g (172421); edamame prepared 11.9 g (168411). link
- Effect of a Food for Special Medical Purposes on Muscle Mass Preservation During GLP-1 RA Weight Loss Treatment (NCT07393360), Pharmanutra, recruiting. link
- Trials of exercise with GLP-1 medicines, recruiting: LEAN-PREP, resistance exercise and protein on semaglutide or tirzepatide (NCT06885736) link; resistance exercise during GLP-1 RA treatment, University of Exeter (NCT07457437) link
- Bellido V, le Roux CW, et al. Retatrutide in adults with obesity and type 2 diabetes (TRIUMPH-2): a double-blind, randomised, placebo-controlled, phase 3 trial. Lancet 2026;408:1455. Published online 29 Sep 2026. PubMed 42810372
Product facts (checked 29 Oct 2026)
- P1 · Momentous Whey Protein Isolate, label and product page. link
- P2 · Momentous 100% Plant Protein, label and product page. link
- P3 · Momentous Creatine (90 servings), label, page FAQ; NSF Certified for Sport listing 1285010. link · NSF
- P4 · Momentous Daily Hydration, labels for all four flavors. link
- P5 · Momentous Fuel, labels for all four flavors. link
- P6 · Kion Aminos powder, Mango label. link
- P7 · PRIMA Ancestral Protein Bar, labels for all six flavors. link
- P8 · Maui Nui Venison Sticks, Original and Peppered nutrition data. Original · Peppered