Creatine

Is creatine safe?

Yes, for healthy adults at the usual dose. Creatine monohydrate has been studied in hundreds of trials since the early 1990s, and the International Society of Sports Nutrition's 2017 review found no good evidence of harm at short- or long-term doses, including studies of up to 30 grams a day for five years. The only consistent side effect is weight gain of a kilo or two, because creatine pulls water into muscle.

If you have kidney disease, the answer changes. And if you buy gummies, there is a fair chance you are not getting creatine at all.

What about the kidneys?

This is the worry people search for most. Creatine breaks down into creatinine, the substance doctors measure in blood to estimate kidney function. Taking creatine raises creatinine a little, so a routine blood test can suggest reduced kidney function when the kidneys are fine. More precise tests, such as cystatin C or measured clearance, usually show no change.

Controlled trials in healthy people, including some lasting several years, have not found kidney damage. Two meta-analyses make the point with numbers: one in BMC Nephrology (2025, 21 studies) and one in the Journal of Renal Nutrition (2026, 20 randomised trials) both found a small rise in serum creatinine (about 0.13 mg/dL in the larger one) and no significant change in estimated filtration rate. The 2026 authors still asked for trials longer than a year. The few published case reports of kidney problems involve people with existing kidney disease, very high doses, or other substances such as anabolic steroids or NSAIDs. That is why we score organ toxicity at 88 and not higher: there is a theoretical risk in people whose kidneys are already under strain.

Tell your doctor you take creatine before any blood test, and ask first if you have kidney disease, diabetes or high blood pressure that affects your kidneys.

Myths that do not hold up

• Cramps and dehydration. Early anecdotes suggested creatine causes cramps and heat illness. Studies in athletes training in heat have found no increase, and some found fewer cramps.
• Hair loss. Based on a single 2009 study showing a rise in DHT, a hormone linked to male-pattern baldness. A 2025 placebo-controlled trial that measured hair follicles directly found no effect on DHT or hair after 12 weeks at 5 grams a day.
• It is a steroid. Creatine is made in the body from amino acids and is found in meat and fish. It is not a hormone and is allowed in tested sport.

Product quality: powder good, gummies poor

Creatine monohydrate powder is one of the most consistently accurate supplements on the market. It is cheap to make, and the dose is large (grams, not micrograms), so small errors matter less. In a June 2025 test commissioned by the supplement-tracking firm SuppCo, all five budget powders bought on Amazon contained about the 5 grams per serving on the label, with low levels of creatinine.

Gummies were a different story. Four of six failed. Two contained no creatine, and the other two had far less than one gram per serving. A 5-gram dose is hard to fit into a sweet, and creatine breaks down to creatinine in moist, warm products; the failed gummies were high in creatinine.

Create, the best-selling gummy, passed the SuppCo test with 4.59 grams against 4.5 on the label. A consumer class action filed in federal court in New York on 22 April 2026 claimed an independent lab had found 4.01 grams per serving instead; Create disputed it, citing its own batch testing through Eurofins. The plaintiff voluntarily dismissed the case in September 2026, and no court ruled on the claim.

Older concerns about contaminants such as dicyandiamide and dihydrotriazine, by-products of cheap manufacturing, are another reason to buy from a reputable maker. Athletes in tested sport should choose NSF Certified for SportThird-party testingTesting of a supplement by an independent lab to check that it contains what the label says and is free of set contaminants.More in the glossary or Informed Sport products, which also screen for banned substances.

Interactions

Creatine has no known major drug interactions, and it is commonly taken alongside caffeine, protein and ordinary vitamins without problems. Because it raises the workload of the kidneys slightly, take care with medicines that are hard on them: regular high-dose ibuprofen or naproxen, some diuretics, lithium, and certain antibiotics such as aminoglycosides. A pharmacist can check your list.

How to take it

1. Use creatine monohydrate. Other forms, such as creatine HCl or buffered creatine, cost more and have less evidence of working or of being safer.
2. Take 3 to 5 grams a day, with or without a loading week.
3. Split large doses if you load, to avoid stomach upset.
4. Drink normally. No special fluid intake is needed beyond what training requires.
5. Pick powder with a third-party seal rather than gummies.

How we scored it

Creatine is among our top supplements on dose safety (91) and regulatory record (94), with strong interaction (90) and organ toxicity (88) scores. Quality (84) is held back by the gummy problem, not the powder. Compare magnesium, another low-risk supplement, and vitamin D, where the margin to a harmful dose is narrower.