Does creatine make you thirsty or cause dehydration?

Creatine draws water into your muscle cells, so some people notice they feel thirstier when they start taking it. That does not mean creatine dehydrates you. Controlled studies, including a systematic review of athletes exercising in the heat, found no evidence that creatine harms hydration or raises the risk of cramps. Normal hydration habits are enough for most people.

By Creatine Today · Editorial policy

Does creatine make you thirsty?

It might, for some people. No study has measured thirst as its main outcome in people taking creatine, so there is no good number for how common it is. There is, however, a clear reason why it could happen.

Creatine is stored in muscle, and it draws water into the muscle cells with it. In a 2003 study, people who took creatine for 4 weeks had a significant increase in total body water and body weight. The balance of water inside and outside their cells did not change. Your body may respond to this shift by making you feel a little thirstier, especially in the first weeks. This is the same water that explains the early weight gain many people see. Our guide on creatine and water retention covers it in more detail.

Feeling thirsty is a normal signal to drink. It is not a sign that creatine is drying you out.

Does creatine cause dehydration?

The research says no. The worry comes from a simple idea: if creatine pulls water into muscle, there may be less water elsewhere in the body, especially when you sweat a lot.

Studies have tested this directly. A 2009 systematic review looked at 10 controlled trials on creatine, hydration, and body temperature control. The authors found no evidence that creatine reduces the body's ability to lose heat or upsets the athlete's fluid balance. In trials where athletes exercised in the heat, creatine at the amounts used in research caused no harmful effects.

A 2021 review of common creatine myths reached the same conclusion: research does not support the idea that creatine causes dehydration.

Does creatine cause muscle cramps?

Cramps are one of the most common complaints people link to creatine. In one survey of 219 athletes, 38% of the creatine users reported side effects they linked to it, and cramping was one of them. But these were personal reports, not compared with athletes who did not take creatine, so they cannot show cause.

Studies that compared groups found no increase in cramps. In a 2003 study of college football players training in temperatures up to 37 °C, players who took creatine had fewer cramps and fewer cases of heat illness or dehydration than players who did not. Players chose for themselves whether to take creatine, so this does not prove that creatine prevents cramps. It does make it unlikely that creatine causes them.

Cramps have many possible causes, such as hard or long exercise, fatigue, and heat. If you get cramps often, or they are severe, talk with a doctor.

How much water should you drink with creatine?

There is no research-based water target that applies only to creatine. The general guidance for everyone is the best place to start.

• The U.S. National Academies report that adequately hydrated women take in about 2.7 liters of total water a day and men about 3.7 liters. This counts water from all drinks and food, and about 20% usually comes from food.
• The same report concluded that most healthy people meet their daily needs by drinking with meals and letting thirst guide them.
• People who are very active or live in hot climates may need more.

Creatine powder is usually mixed into a glass of water or another drink. For ideas, see our guide on what to mix creatine with. If you feel thirstier after starting creatine, drink when you are thirsty. You do not need to force down large amounts of extra water.

Is creatine safe in the heat and during endurance exercise?

The research in hot conditions is reassuring. The 2009 systematic review focused on this question and found no harmful effects of creatine on heat tolerance or hydration in athletes exercising in the heat. A 2008 review went further and noted that some studies suggest creatine may help the body hold on to blood plasma volume and lower heart rate and sweat rate during exercise in the heat. That benefit is less certain.

Long or hot sessions raise your fluid needs whether you take creatine or not. The American College of Sports Medicine advises drinking enough during exercise to avoid losing more than 2% of your body weight through sweat. Weighing yourself before and after training is a simple way to see how much you lose. Sweat rates vary a lot between people.

For how creatine fits into running, cycling, and other endurance sports, see our guide on creatine for runners and endurance athletes.

When to talk to a doctor

Ordinary thirst after starting creatine is not a cause for concern. Strong thirst that does not go away is different. If you are very thirsty all the time, urinate much more than usual, or feel dizzy or unwell, see a doctor. Constant thirst has many possible causes, and it should be checked.

If you have kidney disease, or a doctor has told you to limit how much you drink, talk with your doctor before taking creatine. Our guide on creatine and the kidneys explains what the research shows.