Medically reviewed on Nov 6, 2018
Creatine, creatin, kreatin, creatine monohydrate, creatine phosphate, CrP, methylguanidine acetic acid, N-(aminoiminomethyl)-N-methylglycine, N-amidinosarcosine, phosphocreatine
What is Creatine?
Creatine is a constituent of skeletal muscle tissue of vertebrates, and is obtained through the diet or is synthesized in the body. Herring contains 6.5 to 10 g/kg of creatine, while beef, pork, salmon, and tuna all contain approximately 4 to 5 g/kg. A typical American/Western diet provides 1 to 5 g/day; vegetarians must meet their daily creatine needs via internal synthesis.
Approximately 1 to 2 g/day creatine is synthesized in the kidneys, pancreas, and liver. It is then transported via circulation to various tissues for storage and utilization, particularly in skeletal muscle (95%), with the balance in the brain, kidneys, and testes.
The majority of studies evaluating the effects of oral creatine supplementation have been conducted using creatine monohydrate or the phosphate salt. Creatine monohydrate is available in several doseforms, including bar, capsule, gel, gum, liquid, and powder. Creatine ester and creatine alcohols are marketed as supplements; however, the availability of actual creatine in the preparations is dependent on conversion to creatine within the body, which has not been demonstrated.
What is it used for?
Creatine was discovered in 1832 by the French chemist Michel Chevreul as an organic constituent of meat. In 1847, it was observed that the flesh of wild foxes killed in the chase contained 10 times more creatine than that of those living in captivity, and in 1912 researchers from Harvard Medical School established a link between creatine ingestion and increased creatine in muscle tissue.
In the late 1960s, advances in biopsy techniques allowed researchers to study the breakdown and resynthesis of creatine's chemical compounds; however, it was not until the early 1990s that creatine's influence on exercise performance in humans was studied. Reports followed in 1992 of a 20% increase in human muscle mass subsequent to creatine supplementation, and athletes were reported to have used it prior to the 1992 Olympic Games.
Creatine has enhanced performance in short-duration, high-intensity exercise in limited trials. Creatine supplementation has been extensively studied in muscle and neurodegenerative disorders, but with limited efficacy. Further trials are ongoing.
What is the recommended dosage?
Dosage regimens in clinical trials vary from 2 to 20 g daily, and from 1 to 6 weeks and longer.
Patients with a history of kidney disorders or those taking drugs that are toxic to the kidneys should avoid creatine supplementation or be monitored closely if supplementation is necessary.
Information regarding safety and efficacy in pregnancy and lactation is lacking.
None well documented.
Few adverse reactions have been reported in clinical studies among patients with neurological or muscle disorders, or in healthy individuals.
Concerns regarding kidney and liver toxicity exist; clear proof of safety is lacking and caution is warranted.
Case reports of adverse reactions among athletes include dehydration, electrolyte imbalance, and muscle cramping. Minor GI upset (diarrhea, GI pain, nausea), dizziness, and short-term loss in body mass have also been reported. The safety of creatine in children has not been established.
Information is limited; however, the French Agency for Food, Environmental and Occupational Health & Safety has warned of the potential for production of compounds that are toxic to cells, especially at high dosages.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
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