Creatine

background

Creatine is normally found in meat and fish. Creatine is also naturally made in the human body in the kidney and liver. Creatine is mainly stored in muscles, but about 1.5-2% of the body's creatine is converted to creatinine daily.
The finding that carbohydrates enhance muscle creatine uptake increased the market for creatine sports drinks. Oral consumption of creatine increases the creatine in muscle, which serves to regenerate adenosine triphosphate (ATP).
Creatine supplementation became popular in the 1990s for enhancing athletic performance and building lean body mass. It has also been used in the treatment of chronic heart failure and mitochondrial disorders.
Overall, creatine appears to have modest benefits for intense, repetitive exercise lasting less than 30 seconds. It does not appear to have significant benefits on endurance aerobic exercise.
Caffeine may counteract the benefit of creatine on intermittent exercise performance. Furthermore, creatine in combination with caffeine and ephedra may have adverse effects. However, more research is needed in this area to confirm these interactions.

Related Terms

Beta-GPA, Cr, creatine citrate, creatine ethyl ester, creatine monohydrate, creatine monohydrate powder, creatine phosphate, creatine powder drink mix, creatinine, cyclocreatine, dicreatine citrate, methyl guanidine-acetic acid, methylguanidine-acetic acid, N-amidinosarcosine, N-(aminoiminomethyl)-N-methyl glycine, phosphocreatine, polyethylene glycosylated creatine (PEG-creatine).
Brand name examples: Athletic Series® Creatine, Challenge® Creatine Monohydrate CreapureTM, Creatine Booster®, Creavescent®, Hardcore Formula Creatine Powder®, HPCE Pure Creatine Monohydrate®, Kre-Alkalyn EFX™, Neoton®, Performance Enhancer Creatine Fuel®, PhosphagenTM, Phosphagen Pure Creatine Monohydrate Power Creatine®, Source Natural® Creatine, Total Creatine Transport®.
Combination product examples: Creatine Xtreme Lemonade® (creatine, glucose, glucose polymers, amylopectin starch, hydroxycitrate, citric acid, natural and artificial flavoring, aspartame, potassium citrate, xanthan gum, potassium phosphate, cellulose gum, Piperin, carrageenan, red 40 lake, blue 2 lake, chromium polynicotinate), Creatine Xtreme Punch® (creatine monohydrate, taurine, L-glutamine, L-glutamic acid, hydroxycitrate, vanadyl nicotinate, chromium), Met-Rx® Anabolic Drive Series (micronized creatine, alpha-lipoic acid, glutamine peptide), Muscle Link/Effervescent Creatine Elite® (creatine monohydrate, dextrose), Optimum Nutrition Creatine Liquid Energy Tropical Punch® (pharmaceutical grade creatine monohydrate, methylsulfonylmethane), PhosphagainTM (carbohydrate, protein, fat, creatine, yeast derived RNA, taurine), Runners Advantage® creatine serum (calcium pantothenate, L-glutamine, ginseng extract, calcium pyruvate, inositol, green tea extract, amino acids, phytochemicals, nutrients).

evidence table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
 
Enhanced muscle mass / strength (Grade: A)
Several high-quality studies have shown an increase in muscle mass with creatine use. However, some weaker studies have reported mixed results. Overall, the available evidence suggests that creatine does increase lean body mass, strength, and total work. Future studies should include the effect of individual differences such as fitness levels, sex, and age.
Congestive heart failure (chronic) (Grade: B)
Research supports the use of creatine supplementation in people with chronic heart failure. Several studies have reported a positive outcome of improved muscle strength and endurance.
Adjunct in surgery (coronary heart disease) (Grade: C)
Some research supports creatine supplementation with cardioplegic solution in patients undergoing coronary artery surgery. Benefits include reduced irregular heartbeat and reduced need for defibrillation. Additional research is needed on this topic.
AGAT deficiency (lack of enzyme for creatine production) (Grade: C)
Limited research suggests that long-term creatine use when started early in diagnosis may improve neurologic abilities. Further well-designed studies are needed before conclusions can be made.
Apnea (cessation of breathing) (Grade: C)
Early studies of creatine have found mixed results in infants with a breathing disorder called apnea of prematurity. Well-designed studies are needed to better understand this relationship.
Athletic performance enhancement (aging) (Grade: C)
Aging is associated with lower total creatine and phosphocreatine concentrations. Creatine-induced effects of increased muscle strength, body mass, and performance have not been confirmed in studies on elderly subjects. Additional research is needed in this area.
Athletic performance enhancement (cyclists) (Grade: C)
Most studies lack support for creatine in improving performance in trained cyclists. Further research is needed on this topic.
Athletic performance enhancement (females) (Grade: C)
Recent studies suggest creatine use in females increases the strength and endurance of muscle contractions. Additional research is needed in this area.
Athletic performance enhancement (high-intensity endurance) (Grade: C)
Research suggests that creatine may increase endurance in high-intensity exercise. Further research is needed on this topic.
Athletic performance enhancement (rowers) (Grade: C)
Creatine may offer benefit to rowers, for endurance and speed. Additional research is needed in this area.
Athletic performance enhancement (runners) (Grade: C)
Studies using creatine in runners have mixed results. Overall, most evidence suggests a lack of benefits for runners. However, additional research is needed in this area.
Athletic performance enhancement (specific sports) (Grade: C)
Overall, data suggests that creatine may benefit elite hockey players, football players, rowers, squash players, and wrestlers. Improvement was lacking in tennis players. Additional research is needed in this area.
Athletic performance enhancement (sprinters; general) (Grade: C)
Evidence is mixed regarding creatine use during short bursts of anaerobic muscle activity with short recovery times. Additional research is needed in this area.
Athletic performance enhancement (swimmers) (Grade: C)
Data on effectiveness of creatine for swimming performance shows mixed results. Additional research is needed in this area.
Bone Density (Grade: C)
Early research suggests that creatine may benefit bone density effects combined with resistance training. More studies examining creatine alone are needed.
Cardiovascular health (Grade: C)
Research shows mixed results for creatine use in various cardiac (heart) measurements. Additional research is needed in this area.
Chronic obstructive pulmonary disease (Grade: C)
Limited research reports that creatine supplementation increased muscle mass and exercise performance. Additional research is needed on this topic.
Cognitive function (Grade: C)
Studies evaluating creatine use on cognitive function have reported a lack of benefit. Further well-designed trials are needed in this area.
Dehydration (Grade: C)
The effect of creatine on dehydration shows mixed results. Additional research is needed in this area.
Depression (Grade: C)
Early research suggests a potential benefit of creatine supplements in depression. Additional research is required in this field.
Diabetes (type 2) (Grade: C)
Studies suggest that creatine decreases glucose concentrations with short-term use. Further well-designed, long-term trials are needed.
Dialysis (Grade: C)
Limited research suggests that creatine lacks an effect on homocysteine levels in hemodialysis patients. Creatine may offer some benefit for muscle cramping as a complication of hemodialysis. However, further studies are required on this topic.
Fibromyalgia (nervous system disorder) (Grade: C)
Limited research reports significant effects on severe fibromyalgia when creatine is combined with current medical treatments. Further well-designed studies are needed before conclusions may be made.
GAMT deficiency (lack of an enzyme for creatine production) (Grade: C)
Guanidinoacetate methyltransferase (GAMT) deficiency is diagnosed by a deficiency of creatine in the brain and has been treated with oral creatine supplementation. Early research suggests that creatine is a potentially effective treatment for disorders of creatine production. Further well-designed trials are required.
Heart attack (Grade: C)
Preliminary evidence suggests that phosphocreatine use may offer benefits for heart attack when combined with nifedipine. Additional research is required in this area.
High cholesterol (Grade: C)
Limited research suggests creatine may lower cholesterol. Additional, larger studies are needed to in this area.
Huntington's disease (Grade: C)
Creatine supplementation has mixed results with regards to Huntingdon's disease. Further well-designed studies are required.
Hyperornithinemia (high ornithine levels) (Grade: C)
High amounts of ornithine may lead to blindness, muscle weakness, and reduced storage of creatine in muscles and the brain. Early evidence suggests that long-term creatine supplements may help replace missing creatine and slow vision loss.
Insulin potentiation (Grade: C)
Creatine may have significant effects in insulin release and glucose tolerance. Effects on diabetic patients are unclear. Further well-designed trials are required before conclusions can be made.
Ischemic heart disease (Grade: C)
Early evidence suggests creatine has a potential benefit in the total number of premature ventricular beats. More research is needed in this area.
McArdle's disease (metabolism disorder) (Grade: C)
Creatine may be beneficial for the treatment of McArdle's disease. However, larger trials are necessary before a conclusion can be made.
Memory (Grade: C)
Studies suggest that creatine supplementation increases speed of brain processing in vegetarians and the elderly. Further information is required on this topic.
Multiple sclerosis (Grade: C)
Preliminary results suggest that creatine supplementation does not improve work production in individuals with multiple sclerosis. Additional well-designed studies are required before a conclusion can be made.
Muscle wasting (Grade: C)
According to preliminary research, creatine helped maintain or increase lean body and tissue mass, strength, and endurance in HIV-related and cast-induced muscle wasting. More well-designed clinical trials are needed before conclusions can be made.
Muscular dystrophy (Grade: C)
The decrease of intracellular creatine in Duchenne muscular dystrophy may aggravate muscle weakness and deterioration. Some studies showed preliminary evidence supporting the use of creatine to alleviate these symptoms of muscular dystrophy. More clinical trials are required in this area.
Neuromuscular disorders (general, mitochondrial disorders) (Grade: C)
The evidence for the use of creatine for individuals with neuromuscular diseases is unclear. It is possible that creatine may be useful in some, but not all, mitochondrial diseases. Future studies are needed in this area
Orthostatic hypotension (low blood pressure upon standing) (Grade: C)
One study reported significant effects of creatine with glycerol on orthostatic hypotension. The effects of creatine alone are unclear. Further well-designed clinical trials are required before conclusions can be made.
Osteoarthritis (Grade: C)
Limited research suggests that creatine may improve physical function, lower limb mass, and quality of life in postmenopausal women with osteoarthritis. The effect of creatine alone, without exercise, is unclear.
Parkinson's disease (Grade: C)
In limited research, creatine was reported to slow progression of Parkinson's disease and slightly decrease the use of symptomatic treatment. Further well-designed clinical trials are required on this topic.
Rett syndrome (neurodevelopmental disorder) (Grade: C)
Early research suggests that creatine may be beneficial for Rett syndrome. Additional well-designed trials are required before conclusions can be made.
Skin aging (Grade: C)
Creatine skin products, in combination with other supplementation, may benefit skin aging conditions such as wrinkles, crow's feet, and (ultraviolet) UV damage. Further well-designed trials are needed before conclusions can be made.
Spinal cord injury (Grade: C)
Limited research reports inconclusive results on creatine supplementation for spinal cord injury. Further studies are required in this field.
Traumatic brain injury (Grade: C)
Preliminary evidence suggests creatine may reduce hospital stay and intubation duration in people with traumatic brain injury. Further well-designed clinical trials are needed on this topic.
Amyotrophic lateral sclerosis (ALS) (Grade: D)
Overall, evidence suggests that creatine supplementation does not benefit individuals with amyotrophic lateral sclerosis (ALS). Additional research is needed in this area.
Athletic performance enhancement (endurance; general) (Grade: D)
Data on the effectiveness of creatine in exercise is mixed. For increased endurance during aerobic exercise, the majority of studies failed to demonstrate benefit. Additional research in this area is warranted.
Coronary artery disease (Grade: D)
Preliminary research on creatine supplementation reported a lack of benefit in quality of life, cholesterol, and triglyceride levels in people with coronary artery disease (heart disease). Further well-designed clinical trials are needed before conclusions can be made.
Neurologic disorders (Grade: D)
Early research on the effects of creatine on Angelman syndrome, a genetic neurological disorder found that a combination supplement containing creatine was ineffective in reducing symptoms. Additional research on this topic is needed.
Spinal muscular atrophy (Grade: D)
Early research on the effects of creatine on spinal muscular atrophy reported a lack of significant effects. Further well-designed trials are needed before conclusions can be made.
Surgical recovery (Grade: D)
In preliminary research, creatine supplementation in individuals undergoing soft tissue surgery lacked effects on strength or body composition. Additional research is needed in this area.