Creatine

Creatine is a naturally occurring compound made in the body and found in meat and fish, widely used as a supplement studied for strength, power, and muscle energy.

Last reviewed: June 19, 2026

Overview

Creatine is a naturally occurring nitrogen-containing compound that the human body produces from amino acids and also obtains from animal-based foods such as red meat and fish. It is one of the most extensively studied dietary supplements in the world, with a research record spanning several decades and more than a thousand published studies, and it is best known in the context of strength, power, and high-intensity exercise. Stored largely in skeletal muscle as phosphocreatine, it plays a central role in the rapid regeneration of adenosine triphosphate (ATP), the molecule muscles rely on for short, intense bursts of effort.

What distinguishes creatine from most products in the supplement market is the depth and consistency of its evidence base, particularly for short-duration, high-intensity activity. Major scientific and sports-nutrition organizations describe creatine monohydrate as both effective for certain performance contexts and well tolerated when used appropriately. At the same time, popular discussion of creatine is layered with persistent myths — about kidney damage, "water weight," bloating, and hair loss — that are not always consistent with what the research shows. This page is educational and describes creatine in general terms; it does not provide a regimen or recommend use for any purpose.

What it is

Creatine is synthesized in the body — primarily in the liver, kidneys, and pancreas — from the amino acids glycine, arginine, and methionine, and the remainder of the body's supply comes from the diet, mainly meat and fish. Most of the body's creatine is held in skeletal muscle, where a portion exists as phosphocreatine, a high-energy reserve that helps rapidly replenish ATP during brief, demanding efforts such as sprinting or lifting. Because plant foods contain essentially no creatine, vegetarians and vegans tend to have lower baseline muscle creatine stores, a difference that has been documented in the research literature.

As a supplement, creatine is sold in several chemical forms, but creatine monohydrate is by far the most studied and the form against which others are typically compared. Newer or alternative forms — such as creatine hydrochloride, buffered creatine, and creatine ethyl ester — are marketed with claims about superior absorption or fewer side effects, but the evidence supporting advantages over monohydrate is generally weak, and monohydrate remains the reference standard for both research and value. Creatine is commonly available as a flavorless powder that dissolves in water or other liquids, as well as in capsules and within blended pre-workout or recovery products, where it may appear alongside many other ingredients.

Traditional use (educational)

Unlike botanical remedies with centuries of documented folk use, creatine has no traditional or pre-modern history as an isolated remedy. It was first identified in the nineteenth century as a component of meat, and its story is essentially a scientific and athletic one rather than a cultural or folk one. The "traditional" context most relevant to creatine is dietary: populations that eat meat and fish have always consumed creatine as part of those foods, and the compound's presence in the human body long predates any awareness of it.

Creatine's emergence as a widely used supplement dates to the early 1990s, when it gained attention in connection with Olympic and professional athletics. Since then it has moved from a niche performance aid used by competitive athletes into broad mainstream use among recreational exercisers and, more recently, into research interest in non-athletic populations including older adults. This trajectory — from laboratory curiosity to sports staple to a more general subject of study — is more typical of a researched nutrient than of a traditional remedy, and creatine is best understood in that light.

What research says

Creatine has an unusually robust evidence base for a dietary supplement, but it is important to label the tiers of evidence and the contexts in which they apply. The strongest and most consistent human evidence concerns short-term, predominantly anaerobic exercise: in numerous controlled trials, creatine monohydrate supplementation has been associated with improvements in strength, power output, and performance during high-intensity, intermittent activity such as resistance training and sprint efforts. Authoritative sources, including the National Institutes of Health Office of Dietary Supplements, summarize this body of work as showing benefit for certain types of athletic activity while noting that creatine offers little for endurance sports such as distance running.

Beyond the exercise setting, researchers have explored creatine in a range of other contexts — including cognition, recovery from sleep deprivation, and conditions involving the brain, muscle, and aging. A widely cited position stand from the International Society of Sports Nutrition reviewed more than a thousand studies and concluded that creatine supplementation poses no demonstrated adverse health risks in healthy people and may have applications beyond sport, while emphasizing that many of these therapeutic directions remain areas of active investigation rather than settled conclusions. Some of this work touches on perceptions of mental and physical fatigue under demanding conditions, though such findings are preliminary and context-dependent. The most important limitation across the literature is that benefit is highly specific to context: results in trained athletes performing power activities do not automatically generalize to other populations, outcomes, or claims, and individual responses vary, with some people classified as "non-responders" who show little change in muscle creatine stores.

Safety & interactions

Creatine monohydrate is among the most thoroughly evaluated supplements for safety, and in healthy adults it has a strong tolerability record in both short-term and longer-term studies extending over several years. The most consistently reported effect is a modest gain in body weight, largely attributable to water retention within muscle tissue rather than fat. Some people report gastrointestinal discomfort such as nausea or loose stools, and anecdotal reports mention muscle cramping and heat intolerance, although controlled studies have generally not confirmed cramping as a reliable effect; adequate hydration is often discussed as a sensible accompaniment.

The most persistent safety concern in popular discussion is the idea that creatine harms the kidneys. In people with healthy kidney function, the body of research has not demonstrated kidney damage from appropriate creatine use, although creatine supplementation can raise serum creatinine — a routine marker used to estimate kidney function — which may complicate the interpretation of lab tests and be mistaken for impaired function. This distinction is clinically important and worth flagging to a healthcare provider before testing. Creatine is not associated with a large set of well-documented drug interactions, but combining it with other substances that affect kidney function or fluid balance warrants medical input, and the limited interaction data should not be read as a guarantee of safety in every situation.

Who should be cautious

People with existing kidney disease or reduced kidney function are the group most often advised to exercise caution and to involve a clinician before considering creatine, both because the kidneys are central to creatine metabolism and because supplementation can alter creatinine-based test results. Anyone scheduled for blood work that includes kidney markers should be aware that creatine can affect those values. Individuals with liver conditions, and those taking medications that influence kidney function or hydration status, are also reasonable candidates for professional guidance.

Pregnant and breastfeeding individuals are commonly advised to be cautious simply because creatine supplementation has not been well studied in those populations, so a conservative posture is appropriate. Adolescents and young athletes are another group where caution and adult or medical oversight are frequently recommended, given that much of the safety research has focused on adults. As with any supplement, people managing chronic health conditions or taking prescription medications are best served by discussing creatine with a qualified clinician who can account for their individual circumstances rather than relying on general information.

Quality & sourcing considerations

Because creatine monohydrate is the most studied form and is inexpensive to produce, it offers a practical reference point for quality: products that use plain creatine monohydrate, ideally with third-party testing, are straightforward to evaluate. Purity and manufacturing quality can vary, and contamination or inaccurate labeling has been documented in segments of the broader supplement industry, so independent verification from organizations such as NSF or Informed Sport can offer some assurance — a point that may be particularly relevant for competitive athletes subject to anti-doping rules.

Creatine often appears as one ingredient within complex blended products such as pre-workout or recovery formulas, where the amount present and the presence of other active ingredients may be unclear; single-ingredient products make it easier to know what is actually being consumed. Creatine powder is generally stable when kept dry, but moisture can degrade it over time, so storage in a sealed container away from humidity is sensible. As with the rest of the supplement category, marketing claims about proprietary forms promising dramatic advantages over standard monohydrate should be read skeptically, since the comparative evidence rarely supports them.

FAQs

Does creatine damage the kidneys?
In people with healthy kidney function, research has not shown that appropriate creatine use damages the kidneys, even in studies lasting several years. Creatine can, however, raise serum creatinine, a marker used to estimate kidney function, which may be misread as impaired function on a lab test. People with existing kidney disease, or anyone undergoing kidney-related blood work, should discuss creatine with a clinician first.

Is creatine monohydrate better than other forms?
Creatine monohydrate is the most extensively studied form and the standard against which newer forms are compared. Alternatives such as creatine hydrochloride or buffered creatine are marketed with claims of better absorption or fewer side effects, but the evidence for meaningful advantages over monohydrate is generally weak. Monohydrate is also typically the least expensive option.

Does creatine cause "water weight" or bloating?
Creatine supplementation is commonly associated with a modest gain in body weight, mostly from water drawn into muscle tissue rather than fat. Some people notice this as a feeling of fullness early on. It reflects how creatine works within muscle and is not the same as fat gain.

Can vegetarians and vegans benefit from creatine?
Because creatine is found in meat and fish and is essentially absent from plant foods, people following vegetarian or vegan diets tend to have lower baseline muscle creatine stores. Research suggests these individuals may show a more noticeable response to supplementation in some measures. As with anyone, individual results vary and professional guidance is sensible for those with health conditions.

Is creatine only useful for athletes?
The strongest evidence for creatine concerns strength, power, and high-intensity exercise, so it is most clearly relevant in those settings. Researchers are also investigating creatine in non-athletic contexts such as cognition, recovery, and aging, but these areas remain preliminary. Creatine offers little benefit for pure endurance activities like distance running.