Creatine is often associated with strength training and muscle building. For a long time, it was mainly used by athletes who wanted to improve their performance. Meanwhile, more and more scientific research shows that creatine plays a much broader role in the body.

In addition to its known effects on muscle strength and recovery, creatine also appears to be involved in processes such as energy production, brain function, and possibly even cognitive performance. As a result, interest in creatine is growing not only in the sports world but also in research into health, aging, and brain function (1,2)

In this blog, we explain what creatine is, where it is found in food, what functions it has in the body, and what we know about its use in different life stages such as the menstrual cycle, pregnancy, and menopause.

What is creatine?

Creatine is a natural substance that the body produces in small amounts itself. This occurs primarily in the liver, kidneys, and pancreas from the amino acids glycine, arginine, and methionine. Creatine naturally occurs mainly in animal products. The highest concentrations are found in red meat, fish (such as salmon, tuna, and herring), and poultry. Approximately 95% of the creatine in the body is stored in the muscles, while a smaller part is present in the brain, heart, and other tissues.

In the cells, creatine is converted into phosphocreatine. This substance plays an important role in the rapid release of energy. When cells suddenly need a lot of energy, for example during intense exertion, phosphocreatine helps to quickly regenerate ATP (adenosine triphosphate). ATP is the primary energy carrier of the body. Creatine therefore acts as a kind of energy system that makes rapid energy available when cells need it.

What does creatine do in the body?

The best-known function of creatine is supporting energy production in cells. However, creatine also has other functions than just sports performance.

Energy production

Creatine helps to quickly regenerate ATP. This is especially important for activities that require short, powerful efforts, such as sprinting, jumping, or strength training.

Muscle function and recovery (3)

Creatine can contribute to improved muscle strength, faster recovery between efforts, and support muscle growth during strength training.

Brain and cognitive functions (2,4)

In recent years, interest in the role of creatine in the brain has also grown. Brain cells have high energy requirements and depend on ATP to function properly. Creatine may contribute to the energy supply in brain cells and is therefore being investigated in relation to cognitive performance, mental fatigue, and brain function under conditions such as stress or sleep deprivation. Although this research area is still developing, interest in creatine as a substance that can support not only muscles but also brain processes is growing.

Differences between men and women

Many studies on creatine have long been mainly conducted in men. In recent years, however, the number of studies focusing specifically on women has grown.

There are some physiological differences that may be relevant here. Women generally have lower creatine stores in muscles than men, and hormonal fluctuations may influence creatine metabolism. Some studies suggest that women in certain situations may even respond relatively strongly to creatine supplementation (5).

In addition, research is being conducted into how creatine might play a role during different life stages, such as the menstrual cycle, pregnancy, and menopause. During these periods, hormonal levels and energy requirements change, which may affect energy use, muscle function, and recovery (6). The research field is still relatively young, but the first results suggest that creatine can also play a role for women outside the sports context, for example in processes related to muscle recovery, energy balance, and cognitive functions. (6).

Because research into this is still growing, caution and individual adjustment are always important, especially during pregnancy or with medical conditions.

What is the best dosage?

The most researched dosage of creatine monohydrate is around 3–5 grams per day. Consistent daily intake of 3–5 grams is usually sufficient to gradually increase creatine stores in muscles. Creatine does not necessarily have to be taken at a specific time of day. The most important thing is consistent daily intake.

Many people take creatine around their workout, for example:

• After training (increased blood flow to the muscles)
• With a meal containing carbohydrates and proteins

Food may slightly improve absorption because insulin supports the uptake of creatine into muscle cells.

Are there any side effects?

Creatine is one of the most researched supplements in the world and is generally considered safe for healthy adults.

Possible side effects sometimes mentioned are:

• Temporary weight gain due to fluid in muscle cells
• Mild stomach upset at high doses
• Cramps due to insufficient hydration

At normal doses of 3–5 grams per day, these effects rarely occur.

Conclusion

Creatine has been known for years as a supplement that can support sports performance. At the same time, research shows that the role of creatine is probably broader than just muscle strength and training. Creatine plays an important role in the energy supply of various tissues in the body, including muscles and the brain. What was once mainly seen as a sports supplement, in reality turns out to be part of a much more fundamental energy system of the body.

References

1. Buford, T. W., Kreider, R. B., Stout, J. R., Greenwood, M., Campbell, B., Spano, M., Ziegenfuss, T., Lopez, H., Landis, J., & Antonio, J. (2007). International Society of Sports Nutrition position stand: creatine supplementation and exercise. Journal of the International Society of Sports Nutrition, 4(1), 6. https://doi.org/10.1186/1550-2783-4-6
2. Dolan, E., Gualano, B., & Rawson, E. S. (2018). Beyond muscle: the effects of creatine supplementation on brain creatine, cognitive processing, and traumatic brain injury. European Journal of Sport Science, 19(1), 1–14. https://doi.org/10.1080/17461391.2018.1500644
3. Wax, B., Kerksick, C. M., Jagim, A. R., Mayo, J. J., Lyons, B. C., & Kreider, R. B. (2021). Creatine for Exercise and Sports Performance, with Recovery Considerations for Healthy Populations. Nutrients, 13(6), 1915. https://doi.org/10.3390/nu13061915
4. Avgerinos, K. I., Spyrou, N., Bougioukas, K. I., & Kapogiannis, D. (2018). Effects of creatine supplementation on cognitive function of healthy individuals: A systematic review of randomized controlled trials. Experimental Gerontology, 108, 166–173. https://doi.org/10.1016/j.exger.2018.04.013
5. Smith-Ryan, A. E., Cabre, H. E., Eckerson, J. M., & Candow, D. G. (2021). Creatine Supplementation in Women’s Health: A Lifespan perspective. Nutrients, 13(3), 877. https://doi.org/10.3390/nu13030877
6. Smith-Ryan, A. E., DelBiondo, G. M., Brown, A. F., Kleiner, S. M., Tran, N. T., & Ellery, S. J. (2025). Creatine in women’s health: bridging the gap from menstruation through pregnancy to menopause. Journal of the International Society of Sports Nutrition, 22(1), 2502094. https://doi.org/10.1080/15502783.2025.2502094