Creatine Supplements: An Overview

Medically Reviewed by Zilpah Sheikh, MD on December 11, 2023
10 min read

Creatine is a compound you naturally have in your body. It is an amino acid that comes from other amino acids your body uses to build proteins. You'll find it in your muscles. But it's mostly there in a different form called phosphocreatine or creatine phosphate.

Phosphocreatine helps you make adenosine triphosphate (ATP), which is a source of energy your muscle cells need when you're active. So creatine in your muscles normally is a supply for the energy you'll need during exercise.

Creatine is in your brain, too. Other organs in your body also make creatine in tiny amounts each day. These include your liver, pancreas, and kidneys.

Because creatine is an amino acid, you can get it from foods, such as meat and seafood. But in their quest to run farther, jump higher, and outlast the competition, athletes sometimes turn to a variety of performance-enhancing drugs and supplements including creatine. In the U.S., people spend millions of dollars every year on creatine supplements because they think it will help them build more muscle mass or achieve bursts of strength.

You might also hear about people using creatine to help with brain disorders or other conditions, such as heart failure and muscular dystrophy. If you put creatine on your skin, it may help with aging. Part of the reason for creatine's popular use might also be that it's easy to get. Creatine powder, tablets, energy bars, and drink mixes are available without a doctor's prescription at drug stores, supermarkets, nutrition stores, and online.

Although creatine is a natural substance in your body and is generally safe, its use as a supplement hasn't been well-studied over the long term. It also may not work the same way for everyone. It's always a good idea to talk to your doctor before taking any supplements. 

Creatine vs. creatinine

If you've seen creatine written as creatinine, that's not just a typo. Creatinine is the name of a chemical byproduct of creatine. When creatine in your body is broken down, it makes creatinine. You can find creatinine in your muscles, blood, and pee.

When you take creatine, most of it will end up in your muscles. Your muscles will change it into phosphocreatine by adding phosphoric acid to it.

By taking a creatine supplement, such as creatine monohydrate, you can change the amount of phosphocreatine and creatine in your muscles. The extra creatine can help your muscles make more ATP faster as you use it to fuel your cells during high-intensity exercise.

One reason your body builds more lean muscle tissue when you take creatine is that your muscles will hold more water. The pressure from the water in your cells causes your muscles to swell. This water and swelling can also make cells grow.

Is creatine a steroid?

No. Creatine is not a steroid. While it's a good idea to check with a doctor before taking any supplement including creatine no matter how healthy or fit you are, many athletes take creatine. It is legal to use it, and many sports organizations including the International Olympic Committee and the National Collegiate Athletic Association allow it. Even though it's not a steroid and it's safe for most people to take it, it's not a good idea to overuse it or take too much.

In the 1970s, scientists discovered that taking creatine in supplement form might enhance physical performance. In the 1990s, athletes started to catch on, and creatine became a popular sports supplement. The supplement is particularly popular among high school, college, and professional athletes, especially football and hockey players, wrestlers, and gymnasts.

Creatine is thought to improve strength, increase lean muscle mass, and help the muscles recover more quickly during exercise. This muscular boost may help athletes achieve bursts of speed and energy, especially during short bouts of high-intensity activities such as weight lifting or sprinting. However, scientific research on creatine has been mixed. Although some studies show that it does help improve performance during short periods of athletic activity, there is no evidence that creatine helps with endurance sports like running longer distances. Research also shows that not everyone's muscles respond to creatine. Some people who use it see no benefit.

Most of the studies have been done on young adults around age 20. So it's not clear how well it works in people who are younger or older. Of those studies, a few have suggested a positive effect, but the overall evidence is mixed. In one study, teenage swimmers performed better after taking creatine. In another study, it helped high school soccer players sprint, dribble, and jump better.

Creatine may also help keep you from getting dehydrated by making your muscles hold more water. It may help with muscle cramping and prevent sports or exercise related injuries, too. Taking this supplement could help you recover from exercise faster by healing tiny tears in your muscles.

In addition to your muscles, creatine might have health benefits for other parts of your body, including your heart, brain, bones, and skin. For example, it may help with:

Heart disease. There's some evidence creatine can lower triglyceride levels in your blood if they're too high. Some studies also show it could help people with heart failure get more exercise without feeling fatigued. But not all studies have found this. It may also lower levels of a chemical called homocysteine, which has links to heart attack and stroke.

Cancer. Creatine is thought to slow the growth of tumors. It may also boost the ability of the immune system to fight cancer. But some studies suggest that creatine also can make cancer more likely to spread. You should be careful about taking creatine if you have cancer.

Muscular dystrophy. If you have muscular dystrophy, your cells may have less creatine. Some studies show supplements may help with muscle strength. But it's not clear how well this works long term.

Parkinson's disease. One study suggested that creatine might help with exercise and endurance when you have Parkinson's. It might also help with mood. But a trial testing if it could slow Parkinson's progression over 5 years didn't find that it helped.

Amyotrophic lateral sclerosis (ALS). Taking creatine may help if you have ALS. Some small studies suggested it could help with strength or slow down progression. But a bigger study didn't show that it had significant benefits for slowing the disease. However, the data suggest it might help people with ALS live longer. More study is needed.

Skin aging. A cream with creatine in it may help keep your skin from wrinkling or sagging. It might make your skin produce more collagen and other substances. Some studies have looked at it in combination with other ingredients, including folic acid.

Sarcopenia. Muscle loss happens as you age. By itself, supplements may not help with this. But if you use supplements together with exercise it may help.

Rare genetic syndromes. For people with certain rare conditions that cause a creatine deficiency, supplements may help with symptoms.

Cognition. Supplements might help with brain health and thinking, especially as you get older. But studies have not shown a strong effect. It may be safe to try creatine for brain health, but it might not make a big difference. More study is needed.

You can get creatine in different chemical forms or types:

Creatine monohydrate. This is the most common type you'll find in supplements. It's also been studied more than other types.

Creatine ethyl ester. Experts thought this form might absorb into the body better than creatine monohydrate to make supplements work better. But studies suggest that it doesn't work as well as creatine monohydrate.

Creatine hydrochloride. This form dissolves in water better than creatine monohydrate. But there is no evidence that it works better to build muscle as a result.

Creatine magnesium chelate. One small study suggested this form could improve sprinting ability in well-trained soccer players. But this form hasn't been studied as much.

Buffered creatine monohydrate. One study looked at if a buffered form of creatine monohydrate would get into muscle better to improve exercise capacity more. But the results didn't support that it worked any better or had fewer side effects.

Liquid creatine. Creatine monohydrate often comes as a powder. But you can buy it in liquid form, too.

The bottom line is that most studies have looked at creatine monohydrate. There's not much evidence that other forms work better. No matter which supplement you try, it's a good idea to check with your doctor first. Remember also that the FDA doesn't test or regulate supplements the same way they do with medicines.

Creatine's use in women hasn't been studied as much as it has in men. Women normally have lesser creatine than men. But there's some evidence that taking it can increase your strength and exercise performance. As you get older, it may help with your strength and bone health also.

Some studies show it may also help with your mood and thinking by increasing energy levels in your brain. It's possible creatine may have even more benefit for women than for men. But more study is needed to see how it works in women of different ages.

Your body makes creatine. But you also get creatine from foods. About half of what you have in your body if you don't take supplements comes from your diet. It's mostly in foods with lots of protein. These include:

  • Pork
  • Beef
  • Fish
  • Shellfish
  • Animal milk, including cow, sheep, and goat

Although most healthy people can take it with no problem, creatine can have side effects, particularly when you take too much. Side effects can include:

What happens when you stop taking creatine?

If you take it and then stop, your levels will go down over a few weeks. Your body will still make it, but you may notice side effects as you get to used to having less creatine. These include:

  • Fatigue
  • Muscle loss
  • Weight loss

Your body might make less creatine for a while as you adjust. If you keep exercising, you should stay strong. But you may not keep getting stronger.

Just because creatine is natural, doesn't necessarily mean that it's safe. Supplements aren't held to the same standards by the FDA as medications, which means you can't always know exactly what's in your supplement or in what amounts.

Researchers still don't know the long-term effects of taking creatine supplements, especially in young people. Adolescents who take creatine often do so without their doctor's advice, which can cause them to take more than they should.

Taking the stimulants caffeine and ephedra with creatine can increase the risk of side effects.

Creatine isn't recommended for people with kidney disease, liver disease, or diabetes. Others who should avoid taking it are children under age 18 and women who are pregnant or nursing. Also don't use creatine if you are taking any medication or supplement that could affect your blood sugar because creatine may also affect blood sugar levels. If you have bipolar disorder, it might make mania more likely.

If you do take creatine, drink enough water to prevent dehydration.

No matter how healthy you are, let your doctor know before you take creatine or any other supplement.

How much creatine is safe for kidneys?

If you have kidney disease, creatine might make it worse. Ask your doctor if you are thinking about using it and aren't sure about your kidney function. If your kidneys are healthy, it's generally considered safe. Studies show taking about 5 grams of creatine a day may have benefits for your strength and health.

Creatine is a natural substance in your body and in protein-rich foods. You can also take creatine as a supplement. It's generally considered safe, and there's some evidence it can help to build muscle and strength. But you should always check with your doctor before taking anything new, especially if you are pregnant or have another health condition.

  • Should I take creatine every day?

Creatine is safe for most people to take, but how or whether you take it is a personal decision. It's always a good idea to talk to a doctor about supplements you're thinking about taking and to make sure you aren't taking too much.

  • Does creatine increase testosterone?

There is an idea out there that creatine increases testosterone, and some studies have looked at it. But results have been mixed. For example, one study in rugby players found no change in testosterone. But levels of dihydrotestosterone did go up. More study is needed to understand how its use in the long term affects hormone levels.

  • When should you take creatine?

Some evidence suggests it may work better to take creatine after you exercise instead of before. But the data is lacking, and it's not clear whether the timing of supplements makes much difference. For now, experts say there's no reason to worry about when you take it.