Does creatine make you fat?
No. Randomized trials lasting from one week to two years found no gain in fat from creatine. The weight you see in the first weeks is water that goes into your muscles with it. Fat comes from eating more calories than you burn, and creatine doesn’t change that.
The worry makes sense if you’ve watched the scale. You start creatine, and a week later you’re 3 lb heavier without eating any differently. Nothing else in your life changed, so creatine must have put it there. And it did, as water.
What we’d do
Measure your waist the day you start and once a week after. The scale will go up a little, and your waist won’t, because the extra is water in muscle. If your waist grows, look at what you’re eating.
What the trials found
A 2021 review of the common creatine questions, by a team of creatine researchers, looked at this one directly. It found that trials from one week to two years long don’t back the idea that creatine adds fat. A week of creatine had no effect on fat mass in young or older adults, while their lean mass went up.
The lean mass going up is the part people see on the scale. In a 2003 trial of 32 lifters, body water rose 1.37 L in the first week of loading and 2.04 L by day 28, and weight rose with it. In a 2011 trial at a low dose, about 2.3 g a day for six weeks, 20 people saw no change at all in weight, fat mass or bodyfat percentage.
One trial even found the opposite of a fat gain. In a 2026 trial of 64 adults aged 45 to 65 on a diet and exercise program, the people on creatine lost more of their bodyfat percentage than those on placebo over 12 weeks.
Why the scale lies a little
Your scale weighs everything at once. Water, the food still in your gut, muscle and fat all show up as one number. Creatine moves the water part, by about 1% to 3% of your weight in a loading week and 0% to 2% over a month on 3 to 5 g a day. Over months of lifting it can move the muscle part too. Across 35 trials, people who lifted gained about 2.4 lb (1.1 kg) more lean mass with creatine than without.
It’s like a backpack that got heavier because you filled the water bottle in the side pocket. Nothing else inside changed.
Where fat really comes from
Fat goes up when you take in more calories than you burn over weeks. That’s the number to watch if your waist grows. tdee.guide works out how many calories you burn a day, which is the number that decides fat.
To see your own expected water band by day, use the scale tool.
5 sources
- Antonio J and others, Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show?, JISSN, 2021pmc.ncbi.nlm.nih.gov
- Rawson ES and others, Low-dose creatine supplementation enhances fatigue resistance in the absence of weight gain, Nutrition, 2011pubmed.ncbi.nlm.nih.gov
- Chun J and others, Effects of creatine supplementation with and without exercise and diet intervention on body composition, cognitive function, and markers of health in middle-aged and older adults, JISSN, 2026doi.org
- Powers ME and others, Creatine supplementation increases total body water without altering fluid distribution, Journal of Athletic Training, 2003pmc.ncbi.nlm.nih.gov
- Delpino FM and others, Influence of age, sex, and type of exercise on the efficacy of creatine supplementation on lean body mass, Nutrition, 2022pubmed.ncbi.nlm.nih.gov
