Creatine on a GLP-1: Does It Help Protect Muscle?

Creatine has become the most-discussed supplement among people taking Ozempic and Mounjaro, and for once the enthusiasm is mostly justified. It is one of the few supplements with genuinely strong evidence behind it. But the case for taking it on a GLP-1 rests on an inference rather than direct proof, and it is worth being clear about that before you spend anything.

Why it comes up on a GLP-1

The problem it's meant to address is real. Between 20 and 39% of the weight lost on a GLP-1 can come from lean mass rather than fat. Muscle is what keeps your metabolism up and what stops you arriving at your goal weight weaker than you started, so anything that helps protect it is worth a look.

Creatine's role is straightforward. Your muscles use it to regenerate energy during short, hard efforts. More available creatine means slightly more work per training session, and more work over months means a better stimulus to keep muscle.

What the evidence actually shows

Creatine monohydrate is among the most-studied supplements in existence. The International Society of Sports Nutrition position stand concluded it is both effective for increasing exercise capacity and lean mass, and safe when used as directed, including over long periods.

The most relevant evidence for our purposes comes from resistance training studies. A meta-analysis of 22 studies and 721 older adults found creatine plus resistance training produced 1.37 kg more lean tissue mass than training alone, along with greater gains in chest press and leg press strength. That population matters, because protecting lean mass in people at risk of losing it is exactly the situation you're in on a GLP-1.

Here's the honest gap: no trial has yet reported results for creatine in people taking GLP-1 medications. The reasoning is that if creatine helps preserve lean mass during resistance training generally, it should also help during GLP-1 weight loss. That's a sensible inference from strong evidence, not a proven result. Anyone telling you it's clinically proven for GLP-1 users is going beyond what exists.

The first trial to test it directly is now running. The University of Saskatchewan is recruiting 40 people starting GLP-1 therapy and randomising them to 10 g of creatine a day or placebo alongside a 12-week resistance-training programme. It started in May 2026 and isn't due to report before mid-2027, so it changes nothing about what you should do today. It's worth knowing it exists, and worth treating anyone who claims certainty before then with suspicion. A 2026 review of nutrition during GLP-1 therapy still describes creatine as an adjunct supported mainly by indirect evidence, which is the fair summary.

The one thing that surprises GLP-1 users

Creatine pulls water into your muscle cells. In the first week or two the scale typically rises by roughly one to two kilograms.

On a GLP-1 that lands badly. You are weighing yourself regularly, you are used to the number falling, and suddenly it moves the wrong way. People conclude the medication has stopped working, or that they've done something wrong, and some stop the creatine, the medication, or both.

It is water inside muscle, not fat. Expect it, and don't panic. Track how your clothes fit and how you feel in training rather than reacting to the scale that week. It's the same principle as reading through a weight loss plateau instead of overreacting to a stall.

Where it sits in the order of priorities

Creatine is a genuine multiplier on a good foundation. It is not a replacement for one. In order of what actually protects muscle:

1. Protein. Non-negotiable and by far the largest effect. Higher protein intakes protect lean mass during weight loss. Find your target with the protein calculator and see how much you need.
2. Resistance training. The stimulus that tells your body to keep the muscle. Two to three sessions a week. See how to train on a GLP-1.
3. Enough total food. Severe under-eating undoes both of the above.
4. Creatine. Useful on top of the first three. Close to pointless without number two, since the benefit shows up through training.

If you aren't lifting anything, creatine is not the place to start. Fix the training first.

How to take it

• Creatine monohydrate, 3 to 5 g per day. It has the most evidence and is the cheapest form. The fancier variants charge more for no demonstrated advantage.
• Powder or capsules, not gummies. This is the one place the format matters. NOW Foods tested twelve creatine gummy products and five failed, three of them containing no detectable creatine at all, and an independent lab found near-zero creatine in four of six brands it tested. Creatine is unstable in water, which is the problem gummies have to solve and often don't.
• Skip the loading phase unless you're impatient. Loading fills muscle stores faster, and 3 to 5 g daily gets you to the same place in a few weeks. It also spares your stomach: in 59 athletes, a single 10 g dose caused diarrhoea in 55.6% against 28.6% for the same amount split into two 5 g doses. On a medication that already causes diarrhoea for many people, there is no reason to invite more.
• Timing is unimportant. Consistency is what matters, so attach it to something you already do daily.
• It mixes into anything. That's genuinely useful on a small appetite, since it stirs into a protein shake, yogurt, or coffee without adding bulk to a meal you're struggling to finish.
• Drink enough fluid. Creatine increases water demand slightly, and dehydration is already easy on a GLP-1. See the electrolytes guide.

Tell your doctor before a blood test

This is the practical point most articles miss, and it matters more on a GLP-1 than off one.

Creatine raises serum creatinine, the marker used to estimate kidney function. A 2026 meta-analysis of 19 randomised trials found creatine supplementation increased serum creatinine by about 0.13 mg/dL, with no significant change in urea or estimated GFR. In other words the marker moves, but the kidney function it is meant to estimate does not.

It's a measurement artefact with a simple explanation: creatine breaks down into creatinine, so taking more of it puts more in your blood regardless of how your kidneys are working.

Why this matters here: if you take a GLP-1, and particularly if you have type 2 diabetes, you are likely having kidney bloods checked periodically anyway. A raised creatinine on that panel, in someone on a medication with warnings about dehydration and kidney injury, can look like a problem that isn't there. It can lead to repeat tests, a scan, or being told to stop the medication.

Say that you take creatine before the blood is drawn, and make sure it's on the form. It costs you nothing and saves everyone a scare.

Does creatine cause hair loss?

The claim traces back to a single small 2009 study in rugby players that reported a rise in DHT, a hormone linked to male pattern baldness. It measured no hair outcomes at all. That one result has been repeated for fifteen years.

It has now been tested properly. A 2025 randomised controlled trial gave 5 g a day to resistance-trained men over 12 weeks and measured hormones and hair directly. Across 38 completers there was no change in DHT, no change in the DHT to testosterone ratio, and no change in hair measures.

If your hair is thinning on a GLP-1, creatine is very unlikely to be the reason. Rapid weight loss itself is the more likely cause, and it usually recovers.

Who should check first

Creatine has a strong safety record in healthy adults, and the concern about kidney damage has not been borne out in people with normal kidney function. That said, if you have kidney disease, are pregnant or breastfeeding, or take medication that affects your kidneys, speak to your doctor or pharmacist before starting. GLP-1 medications can also cause dehydration through nausea, vomiting, or diarrhoea, which is worth mentioning in that conversation.

Supplements are also loosely regulated in most countries. Choose a product carrying third-party testing, such as Informed Sport or NSF Certified for Sport, rather than the cheapest tub available.

This is general nutrition information and educational content, not medical advice. Talk to your prescriber, doctor, or a registered dietitian about your own situation before adding any supplement.