Medically reviewed by Austin Baraki, MD
An evidence-based review of creatine supplementation during GLP-1–assisted weight loss.
The Short Answer
Creatine monohydrate is one of the best-studied supplements in sports nutrition, and its effects on body composition are modest. On a GLP-1, creatine will not prevent the lean-mass drop that shows up on a DXA scan, it will not make a low-protein diet adequate, and it will not substitute for resistance training. What 3 to 5 grams per day will do is give you a small boost in the volume and quality of your lifting sessions, and the training is where the body composition benefit comes from.
Over the last year, a number of supplement brands have started marketing creatine specifically to people on GLP-1s, with messaging that implies creatine is the thing standing between you and “catastrophic” muscle loss that is inevitable when taking a GLP-1. Most of those ads have been playing fast and loose with the science. The short version of this article is that creatine is worth taking if you want to, and the reasons to take it are the same reasons anyone on a resistance-training program might take it. There is nothing GLP-1-specific about it.
Important: Creatine is not a standalone muscle-preserving intervention. Its effects depend on resistance training, and without a training stimulus, its impact on body composition is minimal.
For the full picture on muscle loss and body composition during GLP-1 therapy, see our guide on GLP-1s and muscle loss. This article focuses on creatine specifically.
What does creatine actually do?
Creatine is a small molecule your body makes and stores mostly in skeletal muscle, where it gets phosphorylated into phosphocreatine. Phosphocreatine is the fastest way your muscle has to regenerate ATP during short, high-effort work. When you do a heavy set of squats, the first few seconds of that effort are fueled by ATP regenerated from the phosphocreatine pool. Supplementing with creatine raises total muscle creatine stores by roughly 20% on average, and that larger pool translates into a small but real increase in the work you can do before fatigue sets in.1
Energy supply is the headline mechanism, but it is not the only one. Creatine pulls water into the muscle cell, and the resulting cellular swelling appears to act as an anabolic signal that increases muscle protein synthesis and dampens protein breakdown. Creatine also increases satellite cell activation and myonuclear addition when combined with resistance training, which supports hypertrophy on top of the per-set energy benefit.1,6 These mechanisms are part of why the muscle effect shows up only when training is in the picture: the energy advantage gets you a little more work done, and the cellular and satellite cell responses amplify the adaptations to that work.
Over weeks of training, that small per-set advantage adds up. You get through more reps at a given weight, progress a little faster, and accumulate slightly more training volume for the same effort. Across a large body of randomized trials, creatine plus resistance training produces modestly greater gains in lean body mass and strength than resistance training alone, with effect sizes in the range of about 1 to 2 kg of additional lean mass and 5 to 10% additional strength over 8 to 12 weeks of training compared with placebo.2,3 Those are real effects, but they’re not life-changing.
For a complete walkthrough of what creatine does, what dose to take, and the common side effect questions, see our dedicated creatine guide.
Does creatine prevent muscle loss on Ozempic or Mounjaro?
Creatine does not prevent muscle loss on a GLP-1 in the way the marketing implies. It is a small multiplier on the benefits of resistance training, not a standalone muscle-preserving agent, and there is nothing GLP-1-specific about how it works.
The GLP-1 version of the creatine pitch usually goes something like this: people on Ozempic lose muscle, creatine prevents muscle loss, therefore people on Ozempic should take creatine to protect their muscle. Each of those links has a problem.
The first link overstates the muscle loss. The lean-mass numbers quoted from DXA sub studies of GLP-1 trials include water, glycogen, organs, and connective tissue, not only contractile muscle. On top of that, the SURPASS-3 MRI sub study showed that a substantial fraction of the “lean mass” lost on tirzepatide was intramuscular fat, not muscle tissue.9 The story on actual muscle loss during GLP-1 therapy is more nuanced than the headline numbers imply, which we cover in detail in our full guide.
The second link overstates what creatine does on its own. Creatine is not a standalone muscle-preserving agent during a Calorie deficit. The cellular swelling and satellite cell mechanisms described above do support training adaptations, but in the absence of a training stimulus there is no trial that has shown creatine meaningfully protects lean mass in a sedentary person losing weight. The preservation effect reported in the training literature is mediated by the lifting. Give creatine to someone who does not train and the expected effect on body composition during a weight loss phase is close to nothing.
Key point: There is nothing GLP-1-specific about how creatine works. Any benefit during GLP-1–assisted weight loss comes from improved training performance, not a direct effect on muscle preservation.
The third link assumes that the mechanism is GLP-1-specific. It is not. If creatine helps during weight loss on a GLP-1, it helps for the same reason it helps during weight loss from any cause: it lets you train slightly harder, and the training is what moves body composition. The story is the same for someone doing a diet-only weight loss, someone recovering from bariatric surgery, and someone on semaglutide or tirzepatide. There is nothing the drug does that changes how creatine works.
The marketing has gotten creative. A good chunk of the recent GLP-1-adjacent creatine push has been aimed at women through influencer channels, often in the form of creatine gummies and drink mixes built around inferior forms like creatine ethyl ester or creatine HCl at low doses. It’s a real “pink tax”, as most of these products cost more per effective gram of creatine than a tub of plain monohydrate and have worse evidence behind them. The smart move is to ignore the gendered marketing and buy a plain, third-party-tested creatine monohydrate powder, which is what the ISSN position stand has recommended for years.1
What does the research on creatine show?
The short answer: Resistance training plus creatine produces a small increase in lean mass and strength compared to training alone. Creatine without training does much less, and no trial has tested creatine specifically during GLP-1 therapy.
The best summary of creatine’s effects is the International Society of Sports Nutrition position stand, which remains the most comprehensive review of the clinical and performance literature.1
Resistance training plus creatine produces modestly greater gains in lean body mass and strength than resistance training alone, The published meta-analyses in older adults, who are closest to the average GLP-1 patient population, show on the order of 1 kg of additional lean mass and a few additional kilograms on upper- and lower-body strength tests over 10 to 12 weeks.3
Creatine without resistance training produces much smaller and less consistent body composition effects. The signal from sedentary control groups in creatine trials is mostly noise. If you are not going to train, creatine is not going to do much (if anything) for your body composition either on or off a GLP-1.
During a Calorie deficit specifically, the literature on creatine for muscle preservation is thinner than the marketing suggests. Most creatine trials are done in weight-stable or weight-gaining training populations, not in people actively losing weight. The trials that do exist suggest the same modest benefit, mediated through training, that shows up in non-deficit studies.
No direct trials of creatine during GLP-1 therapy have been published. Anyone telling you that creatine has been shown to preserve muscle specifically on Ozempic or Mounjaro is out over their skis when it comes to the evidence.
Does creatine improve cognition on a GLP-1?
Short answer: Creatine’s cognitive effects are modest in sleep-deprived individuals and inconsistent in rested healthy adults. For someone on a GLP-1, this is a possible secondary upside, not a primary reason to start supplementation.
In rested, well-nourished healthy adults, most trials find either no measurable benefit or a small one on specific tasks.4 The effect is more consistent under physiological stress, particularly sleep deprivation. A 2024 crossover trial using a single large dose reported measurable improvements in reaction time and working memory after sleep restriction when subjects had supplemented with creatine.5
If you are already taking creatine for the muscular benefits, you may get a small (perhaps short-lived) cognitive upside when you haven’t slept well. If you are not taking creatine and you are curious about the cognitive angle specifically, the evidence is not yet strong enough to recommend it on that basis alone. It is fair to call the cognition question TBD pending larger and better-powered trials.
Should you take creatine on a GLP-1?
Key point: There is nothing GLP-1-specific about how creatine works. Any benefit during GLP-1–assisted weight loss comes from improved training performance, not a direct effect on muscle preservation.
The case for creatine on a GLP-1 is the same as the baseline case for creatine in any training population. It is inexpensive, it is one of the safest supplements that has been studied at scale, and it gives a small but real edge in training quality that compounds over months. If you are already investing in resistance training and a protein target while on a GLP-1, creatine is a reasonable addition. If you are not training, it is not going to do much of anything for your body composition.
How should I take creatine?
The practical specifics are simple and have not changed in years:
- Dosing should be 3 to 5 grams per day (0.03-0.05 g/kg bodyweight), taken at any time. Timing does not meaningfully affect outcomes in the published trials.
- The loading phase, ~ 20 g per day for 5 to 7 days, is optional. While it does saturate muscle with creatine faster, a steady 3 to 5 g per day gets you to the same place in about three to four weeks. Most people should skip the loading phase and avoid the potential GI side effects that come with it.
- Creatine monohydrate is the preferred form. The more exotic forms (HCl, ethyl ester, buffered, and so on) are all more expensive and none of them have shown a reliable advantage (mostly disadvantages, in fact) over monohydrate in head-to-head studies.1
- Side effects from creatine most commonly center around a mild GI upset at higher doses or when mixed into a small volume of water. The scale weight may go up by 1 to 2 kg in the first few weeks because of increased intramuscular water; this is not fat gain, and it stabilizes within a few weeks. Creatine does not cause long-term water retention, or dehydration for that matter (a common trope that is seemingly at odds with itself).7
If you want to put the levers in order of importance for protecting body composition on a GLP-1: resistance training first, a protein target around 1.6 g/kg of target body weight second (see our protein recommendations and consider Whey Rx if hitting the target on a suppressed appetite is the bottleneck), sleep third, and creatine somewhere after that. It is a nice-to-have, not a must-have.
Frequently Asked Questions
Will creatine prevent muscle loss on Ozempic?
No. Creatine does not directly prevent muscle loss. It works by improving training performance, and the training is what helps preserve muscle during a calorie deficit.
Do I need to load creatine?
No. A loading phase is optional. Taking 3–5 grams per day will fully saturate muscle creatine stores within a few weeks without the increased risk of gastrointestinal side effects.
Is creatine safe to take with GLP-1 medications?
Yes. Creatine monohydrate has an extensive safety record and no known interaction with GLP-1 medications.
Will creatine cause weight gain?
Creatine can cause a small increase in body weight (typically 1–2 kg) due to increased water stored within muscle. This is not fat gain and usually stabilizes after the first few weeks.
Should I take creatine if I’m not lifting weights?
No. Without resistance training, creatine is unlikely to have a meaningful effect on muscle retention or body composition.
Further Reading
For more on GLP-1s, creatine, protein intake, and getting started with resistance training:
-
GLP-1s and Muscle Loss: The Full Guide
The mechanism, the MRI data, and the levers that matter. -
Will You Gain the Weight Back When You Stop Ozempic?
What happens after stopping GLP-1 therapy and how training, protein, and long-term planning fit in. -
Creatine: The Full Barbell Medicine Guide
Dose, timing, myths, and the broader evidence base. -
Protein on Ozempic
How to hit your target on a suppressed appetite. -
Beginner Training Template
Start here if you are new to lifting and on a GLP-1.
References
1. Kreider RB, Kalman DS, Antonio J, 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. PMID: 28615996.
2. Chilibeck PD, Kaviani M, Candow DG, Zello GA. 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;8:213-226. PMID: 29138605.
3. Candow DG, Forbes SC, Chilibeck PD, Cornish SM, Antonio J, Kreider RB. Effectiveness of creatine supplementation on aging muscle and bone: focus on falls prevention and inflammation. J Clin Med. 2019;8(4):488. PMID: 31136007.
4. Avgerinos KI, Spyrou N, Bougioukas KI, Kapogiannis D. Effects of creatine supplementation on cognitive function of healthy individuals: a systematic review of randomized controlled trials. Exp Gerontol. 2018;108:166-173. PMID: 29704637.
5. Gordji-Nejad A, Matusch A, Kleedörfer S, et al. Single dose creatine improves cognitive performance and induces changes in cerebral high energy phosphates during sleep deprivation. Sci Rep. 2024;14:4937. PMID: 38952773.
6. Olsen S, Aagaard P, Kadi F, et al. Creatine supplementation augments the increase in satellite cell and myonuclei number in human skeletal muscle induced by strength training. J Physiol. 2006;573(Pt 2):525-534. PMC1779717.
7. Antonio J, Candow DG, Forbes SC, et al. Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show? J Int Soc Sports Nutr. 2021;18(1):13. PMC7871530.
8. Greenwood M, Kreider RB, Melton C, et al. Creatine supplementation during college football training does not increase the incidence of cramping or injury. Mol Cell Biochem. 2003;244(1-2):83-88. PMID: 12701814.9. Sattar N, McGuire DK, Pavo I, et al. Tirzepatide and muscle volume changes in obesity (SURPASS-3 MRI substudy). Lancet Diabetes Endocrinol. 2025. PMID 40318682.
About the Authors
Jordan Feigenbaum, MD
Jordan Feigenbaum, Founder of Barbell Medicine, has an academic background including a Bachelor of Science in Biology, Master of Science in Anatomy and Physiology, and Doctor of Medicine. He holds accreditations from the American College of Sports Medicine, National Strength and Conditioning Association, USA Weightlifting, and CrossFit, and is a former Starting Strength coach and staff member. He has coached individuals worldwide for over a decade. As a competitive powerlifter, his best lifts include a 640lb squat, 430lb bench press, 275lb overhead press, and 725lb deadlift at a bodyweight of 198lb.
Austin Baraki, MD
Austin Baraki is a practicing Internal Medicine physician, competitive lifter, and strength coach based in San Antonio, Texas. He completed his undergraduate degree in Chemistry at the College of William & Mary, his medical degree at Eastern Virginia Medical School, and Internal Medicine residency at the University of Texas Health Science Center in San Antonio.
