What you need to know about creatine

AURORA, Colo. — Creatine is everywhere right now from fitness influencers to social media, often promoted as a simple way to boost performance, build muscle, and even support overall health. With so much buzz, you may be wondering: is creatine actually effective, and is it right for you? Dr. Jeremy Mosher, a family medicine physician with AdventHealth Medical Group Primary Care at Green Valley Ranch, shares what you need to know.

What is creatine, and how does it work in the body?
Creatine is a natural substance found in your muscles and brain. Your body makes about half of what it needs, and you get the other half from eating meat and fish. Creatine works like a quick energy reserve for your cells, especially during activities that require short bursts of power, like lifting weights or sprinting.

What are the benefits of creatine, and who can benefit from it?
Creatine supplementation can help increase muscle strength, improve performance during high-intensity exercise, and support muscle growth when combined with resistance training. It may also help with recovery after exercise and support brain function.

While creatine is popular among athletes, it’s not just for them. Research shows benefits for anyone doing resistance training or high-intensity exercise. Older adults may benefit from creatine for maintaining muscle mass and strength, improving bone health, and supporting overall physical function. It may also be helpful for individuals recovering from injuries or managing certain medical conditions (in consultation with a health care provider).

Is creatine safe, including for long-term use and older adults?
Yes, research shows creatine is safe and well-tolerated for most healthy individuals, including older adults. Studies have documented safe use for several years, even at higher doses, though typical maintenance doses are 3–5 grams per day. Hundreds of clinical trials have found no greater incidence of adverse effects compared to placebo.

For older adults, creatine combined with resistance training may help combat age-related muscle loss and support strength and independence.

Who should avoid creatine or use caution?
People with pre-existing kidney disease or those at risk for kidney problems (such as individuals with diabetes, high blood pressure, or reduced kidney function) should avoid creatine or use it only under medical supervision. Pregnant and breastfeeding women should also avoid creatine due to limited safety data.

While creatine does not cause kidney damage in healthy individuals, it can increase serum creatinine levels, which may complicate monitoring in those with kidney conditions. It’s also important to inform your doctor if you are taking medications that affect kidney function.

What are common side effects and what should you watch for?
The most common side effect is temporary weight gain (2–4 pounds), primarily due to water retention in muscle cells—not fat gain. Some people may experience mild bloating or gastrointestinal discomfort, such as nausea or diarrhea.

If side effects occur, taking creatine with food or reducing the dose may help. Severe side effects are rare, but if unusual symptoms develop, discontinue use and consult a health care provider.

Do you need to worry about hydration or kidney health?
Early concerns suggested creatine might cause dehydration, but research has not supported this. There is no need to drink excessive amounts of water beyond normal healthy hydration practices.

A common misconception is that creatine harms the kidneys. Current evidence shows it does not cause kidney damage in healthy individuals, though it may affect certain lab values used to assess kidney function.

Should you talk to your doctor before starting creatine?
For healthy adults without underlying conditions, it is not strictly necessary to consult a doctor before starting creatine, though it is always reasonable to do so. Individuals with medical conditions, those taking medications, or anyone who is pregnant or breastfeeding should consult their health care provider first.

How does creatine fit into a healthy lifestyle?
Creatine works best as part of a comprehensive approach that includes regular exercise (especially resistance training), balanced nutrition, adequate protein intake, and sufficient sleep. It is a supplement that enhances healthy habits, not a replacement for them.

In Summary
Creatine monohydrate is one of the most well-studied and safe supplements available. Research supports its benefits for muscle strength, recovery, and performance, with additional potential benefits for brain health and aging populations. When used appropriately, creatine can be a valuable tool to support overall health and fitness.

If you or a loved one needs a primary care physician, Dr. Mosher is accepting new patients. Please click here to learn more or to schedule an appointment.

References
1. International Society of Sports Nutrition Position Stand: Safety and Efficacy of Creatine Supplementation in Exercise, Sport, and Medicine. Kreider RB, Kalman DS, Antonio J, et al. Journal of the International Society of Sports Nutrition. 2017;14:18. doi:10.1186/s12970-017-0173-z.
2. Common Questions and Misconceptions About Creatine Supplementation: What Does the Scientific Evidence Really Show?. Antonio J, Candow DG, Forbes SC, et al. Journal of the International Society of Sports Nutrition. 2021;18(1):13. doi:10.1186/s12970-021-00412-w.
3. Effect of Creatine Supplementation on Kidney Function: A Systematic Review and Meta-Analysis. Naeini EK, Eskandari M, Mortazavi M, Gholaminejad A, Karevan N. BMC Nephrology. 2025;26(1):622. doi:10.1186/s12882-025-04558-6.
4. Effects of Creatine Supplementation on Renal Function: A Systematic Review and Meta-Analysis. de Souza E Silva A, Pertille A, Reis Barbosa CG, et al. Journal of Renal Nutrition : The Official Journal of the Council on Renal Nutrition of the National Kidney Foundation. 2019;29(6):480-489. doi:10.1053/j.jrn.2019.05.004.
5. Studies on the Safety of Creatine Supplementation. Kim HJ, Kim CK, Carpentier A, Poortmans JR. Amino Acids. 2011;40(5):1409-18. doi:10.1007/s00726-011-0878-2.
6. Creatine Supplementation for Older Adults: Focus on Sarcopenia, Osteoporosis, Frailty and Cachexia. Candow DG, Chilibeck PD, Forbes SC, et al. Bone. 2022;162:116467. doi:10.1016/j.bone.2022.116467.
7. Creatine Monohydrate Supplementation for Older Adults and Clinical Populations. Candow DG, Ostojic SM, Chilibeck PD, et al. Journal of the International Society of Sports Nutrition. 2025;22(sup1):2534130. doi:10.1080/15502783.2025.2534130.
8. Muscular Atrophy and Sarcopenia in the Elderly: Is There a Role for Creatine Supplementation?. Dolan E, Artioli GG, Pereira RMR, Gualano B. Biomolecules. 2019;9(11):E642. doi:10.3390/biom9110642.