Creatine helps muscles regenerate energy during short, intense efforts. Taken as creatine monohydrate at 3 to 5 g a day, it modestly improves strength and training results in people who lift or sprint, including older adults who do resistance training. It often adds 0.5 to 1 kg of water weight at first, not fat.
Key takeaways
- Creatine supports short, hard efforts such as lifting and sprinting; it is not a fat burner.
- Creatine monohydrate is the best-studied form; 3 to 5 g a day is a common maintenance dose.
- Older adults who do resistance training gained about 1.4 kg more lean mass with creatine in a meta-analysis of 22 trials.
- Loading often adds roughly 0.5 to 1 kg of water weight, which is not fat gain.
- People with kidney disease, pregnant people and under-18s should talk to a doctor first.
What is creatine?
Creatine is a natural compound that your muscles use to produce energy quickly during short, hard efforts. It is not a hormone, a steroid or a stimulant. Your body makes some of it in the liver and kidneys, and you get the rest from food, mainly red meat and seafood. About 95% of the body's creatine sits in skeletal muscle, with small amounts in the brain and other tissues.
According to the International Society of Sports Nutrition (ISSN) position stand on creatine, the body needs roughly 1 to 3 g a day to replace what is broken down. About half usually comes from the diet and the rest is made by the body. To give a sense of scale, a pound (about 450 g) of uncooked beef or salmon provides about 1 to 2 g of creatine.
What does creatine actually do in the body?
Inside muscle, creatine is stored largely as phosphocreatine. During a sprint, a heavy lift or a jump, muscles burn through their immediate energy supply within seconds, and phosphocreatine helps rebuild it quickly. Supplementing raises the amount stored in muscle, which lets you squeeze out a little more work in repeated short efforts, such as an extra repetition or a faster final sprint.
Over weeks of training, that extra work adds up. The ISSN review concludes that creatine supplementation improves high-intensity exercise capacity and training adaptations, with performance on repeated high-intensity efforts often improving by about 10 to 20% after the muscles are loaded. The benefit is clearest for short, intense, repeated efforts. Creatine is not a fat burner, and it does not replace training, sleep or enough protein.
Who is creatine most likely to help?
| Group | What the evidence suggests |
|---|---|
| People who lift weights or do sprint and interval sports | The best-studied use: more work in short, hard efforts and better training adaptations over time |
| Adults over 50 who do resistance training | A meta-analysis of 22 randomised trials (721 participants, average ages 57 to 70) found about 1.4 kg more lean mass and small extra strength gains with creatine plus training than with training alone |
| Vegetarians and vegans | They usually start with lower muscle creatine stores because their diet supplies little, so they may see larger increases |
| Women | Benefits are reported in both men and women, but most studies were done in men, and some suggest women may gain a little less strength or muscle |
| People who mostly walk or do steady cardio | Less likely to notice a difference, because creatine supports short, intense efforts rather than long, steady ones |
The older-adult finding is worth stressing: creatine was studied together with resistance training two or three times a week. Without the training, the effect on muscle would not be expected to appear. If you are older and want to keep muscle, the foundations are regular strength work and enough protein spread across your meals; the guide to protein for older adults covers that side.
How much creatine do people take?
Creatine monohydrate is by far the most studied form. Other forms are often more expensive, without strong evidence that they work better. The ISSN describes two common approaches:
| Approach | How it works | Example for a 70 kg adult |
|---|---|---|
| Loading, then maintenance | About 0.3 g per kg of body weight a day, split into four doses, for 5 to 7 days; then 3 to 5 g a day | About 21 g a day (four doses of about 5 g) for a week, then 3 to 5 g a day |
| Steady daily dose | 3 g a day; muscle stores rise more slowly, over about four weeks | 3 g a day from the start |
Both routes end up in the same place; loading simply gets there faster. Larger athletes may use 5 to 10 g a day for maintenance. Timing matters less than taking it consistently, so many people simply add it to a meal or a drink they already have. Creatine itself provides practically no calories, so it does not change your calorie target.
Will creatine make the scale go up?
Often, yes, at least at first. This is the one side effect that the ISSN review describes as consistently reported. When muscles take up more creatine, they also hold more water. During loading, people typically retain roughly 0.5 to 1 litre of extra fluid, which can show up as a jump of around 0.5 to 1 kg on the scale within days.
That is water in muscle, not body fat. Fat gain requires eating more energy than you use over time, and a 5 g scoop of creatine does not add meaningful calories. If you are in a calorie deficit and start creatine, expect the scale to be noisy for a week or two, and judge progress by your weekly average and your waist measurement rather than a single morning weigh-in. The article on water weight versus fat loss explains how to read these swings. If you log your meals in Sporty and your intake has not changed, a sudden small rise after starting creatine is very likely water.
Is creatine safe?
Creatine is one of the most researched sports supplements. The ISSN position stand concludes that, in short- and long-term studies, creatine monohydrate at recommended doses has not shown adverse health risks in healthy people. Case reports raised concerns about the kidneys, but the review found no compelling evidence of harm to kidney function in healthy or clinical groups.
A few sensible precautions still apply:
- Kidney disease or reduced kidney function. Talk to your doctor before taking creatine. The ISSN itself suggests caution in this group.
- Pregnancy, breastfeeding and under 18. Ask a doctor or registered dietitian first, since most studies were done in healthy adults.
- Medications and medical conditions. If you take regular medication, check with your doctor or pharmacist.
- Product quality. Supplements are less tightly regulated than medicines. Choose plain creatine monohydrate from a reputable brand, ideally one that uses independent third-party testing.
Note that much of the creatine research is supported by the supplement industry, and several authors of the ISSN review disclosed such ties. The body of evidence is still large and consistent, but it is a reason to keep expectations modest.
Do you need creatine to lose fat or build muscle?
No. Creatine is an optional extra for people who already train regularly. Most of your results come from the basics: a sensible calorie target, regular resistance training, enough protein and enough sleep. For people who exercise, the ISSN suggests about 1.4 to 2.0 g of protein per kg of body weight a day. The guide to strength training and weight loss explains why keeping muscle matters while you lose fat, and the article on protein powder looks at another supplement people often wonder about.
If you do decide to try creatine, give it at least four weeks alongside consistent training before judging it, and keep in mind that the effect is real but modest. It will not make up for missed sessions or very low protein intake.
This article is general information, not medical advice. If you have kidney disease or another medical condition, take regular medication, are pregnant or breastfeeding, or are under 18, talk to a doctor or registered dietitian before taking any supplement.
Frequently asked questions
Does creatine make you gain fat?
No. Creatine provides practically no calories. The early weight gain, often about 0.5 to 1 kg, is mainly extra water stored in muscle.
Do you need to do a loading phase?
No. Loading fills muscle stores within about a week, while 3 g a day reaches the same level in about four weeks. Both approaches work.
Is creatine bad for your kidneys?
In healthy people, studies have not shown harm to kidney function at recommended doses. If you have kidney disease or reduced kidney function, talk to your doctor before taking it.
Is creatine useful for women and older adults?
Benefits have been reported in both sexes, though most studies were in men. In older adults, creatine combined with resistance training increased lean mass and strength slightly more than training alone.
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Sources
- Kreider et al. 2017, ISSN position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine
- Chilibeck et al. 2017, Creatine during resistance training in older adults: meta-analysis of 22 RCTs (721 participants)
- ISSN position stand: protein and exercise (Jäger et al. 2017)
This article is general information, not medical advice. If you have a health condition, are pregnant or under 18, talk to a doctor or registered dietitian before changing your diet.