creatine monohydrate

Creatine is a compound the body makes on its own — the liver and kidneys produce roughly a gram a day from amino acids — and that we also take in from animal-based foods such as red meat, pork, and fish. Most of it is stored in skeletal muscle, where it helps regenerate the rapid energy (ATP) used for brief, intense effort. Creatine monohydrate is the form used in most studies, and the NIH Office of Dietary Supplements treats it as one of the more extensively studied and widely used supplements aimed at exercise and athletic performance.

According to the NIH Office of Dietary Supplements, research fairly consistently suggests creatine can help increase strength and power and improve the ability to perform repeated short bouts of high-intensity, intermittent activity like sprinting and weight lifting. The same source notes the benefit appears specific to that kind of effort: creatine seems to be of little value for endurance activities such as distance running or swimming, and the associated water-weight gain may actually work against performance in those sports.

A frequently studied approach is a short "loading" period of around 20 grams per day (typically divided into about four smaller doses) for roughly 5 to 7 days, followed by a lower maintenance dose of about 3 to 5 grams per day; some people skip the loading phase and just take the lower daily amount. These figures reflect the regimens the NIH summarizes from research, not a personal recommendation — check with a clinician or registered dietitian about whether creatine and what amount are appropriate for you.

The NIH Office of Dietary Supplements describes creatine as safe for short-term use in healthy adults, and notes evidence that use over several years also appears safe in healthy people. Its safety in children and adolescents is not well established, and major medical groups generally advise teens against performance-enhancing supplements. Evidence is lacking for people who are pregnant or breastfeeding and for those with kidney problems or other health conditions, so anyone in these groups should talk with a healthcare provider before use.

The most common effect is weight gain, much of it from extra water held in muscle (on the order of a kilogram or two over a month). Reported side effects also include nausea, diarrhea and other digestive upset, and muscle cramps, with stomach complaints somewhat more likely at higher doses. Notably, controlled studies have generally not confirmed that creatine itself causes exercise-related muscle cramps, despite cramps being commonly reported.

The NIH Office of Dietary Supplements fact sheet does not highlight specific drug interactions for creatine. The main caution it raises relates to the kidneys, so extra care is reasonable for people with existing kidney problems or those taking medicines that can affect kidney function. Because how supplements and medications interact can vary from person to person, review your full list of medications and supplements with a healthcare provider before adding creatine.