In short
Creatine is one of the better-studied supplements and its main use here is supporting strength work, which is what protects muscle while you lose weight. It.
By Alsen Walker · Updated September 19, 2026
Creatine is one of the better-studied supplements and its main use here is supporting strength work, which is what protects muscle while you lose weight. It is not a weight loss aid, and it commonly causes a small increase on the scale from water held inside muscle, which is worth expecting rather than being alarmed by.
Ask before starting if you have kidney problems, take medications affecting the kidneys, or have been told to limit fluids. Creatine is generally well tolerated in healthy people, and reduced kidney function changes that conversation. Tell your prescriber what you are taking either way.
For how this fits alongside the rest of eating and training on a GLP-1, see Eating and Training on a GLP-1: The Complete Guide.
What it actually does
Creatine supports short bursts of muscular effort, which means you can do slightly more work in a resistance session. Over time that extra work is what drives muscle retention and strength.
It does not burn fat, suppress appetite or accelerate weight loss. Its value here is entirely through supporting the training that protects lean tissue.
The scale effect
Creatine draws water into muscle cells, and most people see a small increase on the scale in the first weeks.
That is water inside muscle, not fat, and it is not a sign the medication has stopped working. It matters here because people on these medications watch the scale closely and an unexplained rise can be discouraging enough to stop something useful.
Knowing to expect it usually removes the problem.
Practical points on these medications
Creatine works better with adequate hydration, and dehydration is already common here. If you are struggling to drink enough, address that first.
Powder mixed into a protein drink is usually easier than another separate thing to swallow when appetite is poor.
Some people report mild stomach upset, which is more noticeable on a slowly emptying stomach. Taking it with food and splitting it across the day helps.
Quality
Supplements are regulated less tightly than medicines, so content is not guaranteed to match the label. Independent third-party testing programs certify products for content and contaminants, and looking for that certification is a reasonable filter for anything taken daily.
Creatine monohydrate is the most studied form. More expensive variants are heavily marketed and have not shown consistent advantages.
Who should be cautious
Anyone with reduced kidney function or kidney disease. Anyone taking medications that affect the kidneys, including some anti-inflammatories and diuretics. Anyone with a fluid restriction.
Given that dehydration and kidney injury are the main serious risks associated with this drug class, this is a supplement worth mentioning to your prescriber rather than starting quietly.
The small scale increase is water in muscle rather than fat, which matters if a plateau is already discouraging you, as the plateau guide explains. Hydration and kidney function are the things to check first, covered in kidney function on GLP-1s.
Frequently asked questions
Will it make me gain weight?
A small increase from water in muscle is common. It is not fat.
Does it help without training?
Little. Its benefit comes through supporting resistance work.
Is it safe with a GLP-1?
No known direct interaction, and hydration and kidney function are the things to consider. Tell your prescriber.
Do I need to load?
Loading protocols exist and are not required. Ask your pharmacist about a sensible approach.
Which form should I buy?
Monohydrate is the most evidenced. Look for third-party testing.
Can I take it long term?
It has been studied over extended periods in healthy people. Discuss it if you have kidney concerns.
Sources and further reading
- National Institute of Diabetes and Digestive and Kidney Diseases (NIH). Treatment for overweight and obesity. www.niddk.nih.gov
- MedlinePlus (US National Library of Medicine). Semaglutide injection: drug information. medlineplus.gov
- MedlinePlus (US National Library of Medicine). Tirzepatide injection: drug information. medlineplus.gov
- National Institute of Diabetes and Digestive and Kidney Diseases (NIH). Prescription medications to treat overweight and obesity. www.niddk.nih.gov
GLP1Hub content is for general information and is not medical advice. Prices and coverage rules change often, so confirm current details with the provider, your insurer and your prescriber. See our editorial standards and medical disclaimer.
