Creatine monohydrate is one of the most studied supplements in sports, and it adds weight during the first days of use. For a fighter who has to make a division limit, the same question comes up every camp: keep taking creatine through the weigh-in or stop before the cut.
| Question | What the sources say |
| Weight gain at the start | About 2 to 4.5 lb in the first week of a loading phase (ISSN, 2007) |
| Time to return to baseline after stopping | 4 to 6 weeks for muscle stores (ISSN, 2007) |
| Effect on rapid weight loss | No impairment found, water weight manageable during the cut (Ashtary-Larky et al. review, 2025) |
| Typical maintenance dose | 3 to 5 g per day (ISSN, 2007) |
Why creatine moves the scale
Creatine builds up in muscle, and muscle stores water with it. The 2007 position stand from the International Society of Sports Nutrition (ISSN) states that proper supplementation increases body mass by about 1 to 2 kg, roughly 2 to 4.5 lb, during the first week of loading. The same paper describes the standard load at about 0.3 g per kilogram of body weight per day, or about 0.14 g per pound, for 5 to 7 days, followed by 3 to 5 g per day to keep stores elevated.
A systematic review on combat sports published in 2025 in the Journal of Dietary Supplements by Damoon Ashtary-Larky and colleagues calls this gain modest and attributes it mostly to fat-free mass. The authors conclude that creatine does not appear to impair rapid weight-cutting strategies and that the associated water weight can be managed during the cut.
On performance, the 2018 International Olympic Committee (IOC) consensus lists creatine monohydrate among the few supplements with enough evidence behind them, with a possible effect on strength and power efforts. The 2017 ISSN position stand on creatine reaches a similar conclusion for high-intensity, repeated efforts.
See price on AmazonKeeping creatine through the cut
A fighter who has taken 3 to 5 g a day for several weeks has already absorbed the weight gain from loading. Creatine no longer moves the scale, and stores stay full for training after the weigh-in. The 2025 ISSN position stand on nutrition and weight cutting in MMA places supplements that build up in muscle in the general preparation phase, so they have time to reach useful levels.
For the longer part of camp, the 2025 ISSN position stand recommends a gradual loss of about 0.5 to 1 kg per week, roughly 1 to 2 lb. That pace leaves room for creatine’s water weight without pushing a larger share of the cut into the final days before the weigh-in.
This option suits a fighter whose walking weight stays close to the limit and who does not rely on the last few pounds of water to make weight.
Stopping creatine before the weigh-in
The 2007 ISSN paper puts the return of muscle stores to baseline at 4 to 6 weeks after stopping. Dropping creatine the day before a weigh-in barely changes the number on the scale. A fighter who wants to lose the 2 to 4.5 lb linked to creatine has to stop at least a month before the fight, and gives up those stores when they matter most.
Starting a loading phase during camp, a few weeks out from the weigh-in, adds weight at the worst time. Fighters new to creatine are better off starting outside of camp, at a 3 to 5 g maintenance dose with no loading phase.
The weigh-in, then rehydration
The 2025 ISSN position stand notes that losing 2.5 percent of body weight through dehydration can already hurt performance. For professional MMA, the paper lists a sweat loss of 4 to 6 percent of body weight before the weigh-in. A Gatorade Sports Science Institute paper by Reale and colleagues calls losing 5 to 8 percent through dehydration alone dangerous, and describes a low-fiber diet, 10 g a day or less for 48 hours, as the least harmful strategy.
After the weigh-in, the ISSN puts oral rehydration solutions first, at about 34 to 50 oz per hour, followed by fast-acting carbohydrates up to 60 g per hour. The Reale paper sets the target at 125 to 150 percent of the fluid deficit, starting with 20 to 30 oz right after stepping off the scale. Creatine goes back into the routine once normal meals resume.
See price on AmazonSafety and anti-doping
The IOC reports that about 15 percent of more than 600 supplements bought worldwide contained undeclared prohormones, so a tested fighter should pick a product carrying NSF Certified for Sport. People under 18, pregnant or breastfeeding women and anyone with heart disease, cardiovascular risk factors or reduced kidney or liver function should avoid these supplements, as France’s food safety agency Anses advised in December 2016. None of the products mentioned here were tried by our editorial team.
Frequently asked questions
Should I stop creatine a week before weigh-in?
A one-week break barely lowers body weight, since the ISSN puts the return of muscle stores to baseline at 4 to 6 weeks.
Does creatine cause bloating or water under the skin?
The extra water is stored inside muscle along with creatine. The 2025 combat sports review attributes most of the weight gain to fat-free mass.
Can I take creatine right after weigh-in?
Yes. The sources reviewed put fluids, sodium and carbohydrates first after the weigh-in. Creatine returns at the usual dose with the following meals, with no loading phase.
