Safety

Does creatine cause cramps?

By GyroscopeUpdated November 14, 20264 sources

No. Over a season of college football in hot, humid weather, players taking creatine had fewer cramps, less heat illness and dehydration, and fewer muscle strains than players who weren’t. The cramp stories mostly come from surveys of athletes taking far more than the usual dose.

The cramp idea has a tidy logic. Creatine pulls water into your muscles, so maybe it pulls water out of everywhere else, leaving you dry and crampy in the heat. In the early 2000s, with little data to go on, the American College of Sports Medicine advised people cutting weight or training hard in hot conditions to avoid creatine.

What the surveys said

The early reports were surveys. In one, 90 of 219 athletes used creatine, and 34 of them said they’d had bad effects, with cramping the most common at 27%. In another, 25% of 52 college baseball and football players on creatine reported cramps. Those surveys didn’t control for other supplements or the dose, and in the first one 91% of the creatine users took more than the usual 5 g a day.

What happened when someone counted

Then a research group led by Greenwood followed 72 college football players through a season in hot, humid weather, about 81°F (27°C) with 54% humidity. 38 chose to take creatine, loading at 0.3 g per kg for 5 days and then 0.03 g per kg a day, and 34 took a sports drink instead. The team’s athletic trainers logged every injury they treated.

The creatine group had less cramping, less heat illness and dehydration, less muscle tightness, fewer muscle strains and fewer injuries overall. Other injuries, illnesses and missed practices didn’t differ.

The limit is that players chose their own group instead of being randomly assigned, so the two groups may have differed in other ways. But a supplement that dried people out in the heat should have shown up there, in a full season of hard practice, and it went the other way.

Where the water goes

In a 2003 trial of 32 lifters that measured body water with tracers, loading raised total body water 1.37 L in the first week, and the split between water inside and outside the cells stayed the same. Creatine added water to the body as a whole without drying out one part of it.

It’s like packing two extra water bottles in your backpack. You’re carrying more water, and nothing else in the bag got any drier.

The one number on the other side

A 2025 count of 685 creatine trials from Kreider’s lab found muscle cramping or pain mentioned in 2.9% of the creatine groups and 0.9% of the placebo groups. Those are shares of trials that mentioned it at all, counted in a conference abstract, and they don’t tell you how many people. It’s a small difference, and the season-long football data point the other way.

Where the expert groups stand

• 2021 review by creatine researchers. Experimental and clinical research doesn’t support the idea that creatine causes dehydration or muscle cramping.
• International Society of Sports Nutrition, 2017. Creatine users in college football had less cramping, heat illness and dehydration than non-users. Short and long-term use is safe and well tolerated in healthy people.

Checked against these sources on November 14, 2026.