Creatine side effects, separated from the myths

What people ask us next.

Q01

Is creatine bad for your kidneys?

Not in healthy adults. The fear comes from a measurement artifact: creatine breaks down to creatinine, the marker labs use to estimate kidney function, so supplementing raises serial creatinine mechanically without any kidney damage. Trials measuring true glomerular filtration rate (de Souza e Silva 2019; Kreider 2017 ISSN stand) find no adverse renal effect at 3-5 g/day, including multi-year use. The exception is pre-existing chronic kidney disease, which warrants medical supervision. Tell your doctor you take creatine so a high creatinine reading is not misinterpreted.

Q02

Does creatine cause hair loss?

There is no controlled evidence that it does. The entire claim rests on one study (Van der Merwe et al. 2009, 20 rugby players) that found a ~56% rise in DHT after a creatine load, with DHT staying inside the normal range. It measured a hormone, not hair, and has never been replicated in over 15 years. No trial has ever measured actual hair loss from creatine as an endpoint. A predisposition to male-pattern baldness is theoretically the only relevant scenario, and even there the direct evidence does not exist.

Q03

Why am I gaining weight on creatine?

It is water, not fat. Creatine draws 1-2 kg of water into muscle cells over the first 2-4 weeks (Francaux & Poortmans 2003). This is intracellular, not under-skin, so it does not make you look softer, and it is part of how creatine works. After saturation, weight stabilizes. If you want to minimize the visible jump, skip the 20 g/day loading phase and take 3-5 g/day instead, which spreads the same water gain over several weeks.

Q04

Does creatine cause bloating or stomach problems?

Mainly at high doses. GI upset (nausea, diarrhea, cramps) is dose-dependent and concentrates in the loading phase (20 g/day) or when a large dose is taken on an empty stomach (Ostojic & Ahmetovic 2008). At 3-5 g/day taken with food and fully dissolved, GI complaints are minimal. 'Bloating' is usually the intracellular water gain rather than gut bloat. Use micronized monohydrate, skip loading, and take it with a meal to avoid the issue.

Q05

Does creatine cause cramps or dehydration?

No, and the controlled data points the opposite way. Greenwood et al. 2003 tracked 72 college football players over a season and found creatine users had fewer cramps, injuries, and heat-illness episodes than non-users. A meta-analysis (Lopez et al. 2009) found no impairment of thermoregulation or hydration. The cramping-and-dehydration claim is one of the most thoroughly disproven myths in the supplement literature.

Q06

Do you have to load creatine, and does loading cause side effects?

You do not have to load. Loading (20 g/day for 5-7 days) only saturates muscle ~2 weeks faster; final saturation is identical to 3-5 g/day (Hultman 1996). Loading is also where most reported side effects (GI upset, the rapid water jump) come from. The low-side-effect protocol is 3-5 g/day from day one, with a meal, no loading. You reach the same muscle creatine level by week 4 with none of the acute downsides.

Q07

Is creatine safe long-term?

Yes for healthy adults. Kreider et al. 2017 reviewed studies running beyond 4 years and found no adverse renal, hepatic, or cardiovascular effects at 3-5 g/day. Creatine monohydrate is one of the most studied supplements in sports nutrition, with over 1,000 published studies. The only firm caveat is pre-existing chronic kidney disease, where medical supervision is warranted. For a healthy adult, the long-term safety record is excellent.