Creatine is a nitrogenous organic acid produced in the liver; it helps supply energy to cells throughout the body - particularly muscle cells.
The compound is formed of three amino acids: L-arginine, glycine, and L-methionine and makes up about 1 percent of the total volume of human blood.
Creatine is transported through the blood by an active transport system; it is then used by parts of the body that have high energy demands, such as skeletal muscle and the brain.
Around 95 percent of creatine in the human body is stored in skeletal muscle.
In this article, we will look at the potential medical uses of creatine and any accompanying evidence, how creatine works, and any side effects it might cause.
Contents of this article:
Fast facts on creatine
Here are some key points about creatine. More detail and supporting information is in the main article.
- Athletes use creatine to assist in high-intensity training
- Creatine can cause water retention
- Creatine is being studied for use in a number of diseases including Parkinson's disease and depression
- Because creatine helps build muscle, it may be useful for individuals with muscular dystrophy
- There is some evidence that creatine can boost memory
What is creatine?
Athletes take creatine to increase their athletic output.
The French chemist, Michel Eugène Chevreul, first identified creatine in 1832. The chemical is naturally made by the body, but it can also be obtained from some foods and supplements.
Because of creatine's ability to supply energy where it is demanded, the chemical is mainly used by athletes to rapidly increase their energy production, improving athletic performance and allowing them to train harder.
The International Olympic Committee and the National Collegiate Athletic Association (NCAA) allow the usage of creatine, and it is widely used among professional athletes.
According to an NCAA report, creatine is one of the most popular supplements; men who play ice hockey, football, baseball, lacrosse, and wrestling were found to use creatine most often.
Creatine is not only used by athletes to improve their overall performance, but it may also help treat a range of neuromuscular and neurodegenerative disorders and improve cognitive ability.
Uses for creatine with strong supporting evidence
First, we will cover areas where there is good evidence that creatine can be helpful. Later, we will discuss cases where the evidence is less conclusive, or contradictory.
Improving athletic performance
Creatine supplements are commonly used by athletes because of their effectiveness in high-intensity training.
People take creatine because it allows the body to produce more energy, and with more energy "you can lift one or two more reps or 5 more pounds" and "your muscles will get bigger and stronger," said Chad Kerksick, Ph.D., assistant professor of exercise physiology at the University of Oklahoma.
Researchers published findings in the Journal of Sports Science and Medicine suggesting that creatine use can increase maximum power and performance in high-intensity anaerobic repetitive work by up to 15 percent.
Increased muscle creatine content is associated with greater body mass and total body water volume.
A study published in the Journal of Athletic Training reported that creatine supplementation increased body mass; it also resulted in water retention, but fluid distribution did not change.
Creatine and muscular dystrophy
Creatine may also help improve the strength of people who have muscular dystrophy. For instance, one German study found that people with muscular dystrophy who took creatine experienced an increase in muscle strength of 8.5 percent compared with those who did not take the supplement.
Dr. Rudolf Kley, of Ruhr University Bochum, Germany, lead reviewer of the study, said that the finding "shows that short- and medium-term creatine treatment improves muscle strength in people with muscular dystrophies and is well-tolerated."
Uses for creatine with weak evidence
The following uses for creatine have less evidence to support them, or contradictory findings:
Creatine for Parkinson's disease
In mice models of Parkinson's disease, creatine was able to prevent the loss of cells that are typically affected by the condition.
Research, published in the Journal of Neurochemistry, concluded that "combination therapy using Coenzyme Q(10) and creatine may be useful in the treatment of neurodegenerative diseases such as Parkinson's disease and [Huntington's disease]" in animal models.
However, research published in JAMA using more than 1,700 human participants concluded that "treatment with creatine monohydrate for at least 5 years, compared with placebo did not improve clinical outcomes."
Similarly, a systematic review published in Cochrane concluded that there was no strong evidence for the use of creatine in Parkinson's.
Creatine for treating depression
It is possible that creatine could be useful in treating depression.
It may come as a surprise that a supplement for athletes has properties that can help alleviate the symptoms of depression, but evidence shows that it might be the case.
Researchers at three different South Korean universities found that women with depression who augmented their daily antidepressant with 5 grams of creatine responded twice as fast and experienced remission of the illness at twice the rate, compared with women who took the antidepressant alone.
Another study looked at the use of creatine in treating depression in methamphetamine-addicted females. Although the study was small-scale, they concluded:
"The current study suggests that creatine treatment may be a promising therapeutic approach for females with depression and comorbid methamphetamine dependence."
Creatine boosts brain power
Researchers from the University of Sydney and Macquarie University, both in Australia, found evidence that creatine can boost memory and intelligence.
Dr. Caroline Rae, who led the study, said that "the results were clear with both our experimental groups and in both test scenarios. Creatine supplementation gave a significant measurable boost to brain power."
Another study, published in The Journal of Neuroscience, found that during oxygen deprivation, creatine "prevents the decline in attention."
A group of researchers published the results of another study in a similar vein in 2007. They looked at the effects of creatine supplements on the cognitive abilities of older adults. They used a number of cognitive tests to examine the influence of creatine.
Although the study group was small, the results were positive. They found a "significant effect of creatine supplementation on all tasks except backward number recall. It was concluded that creatine supplementation aids cognition in the elderly."
Side effects and precautions for creatine
At recommended doses, creatine is considered safe to consume. However, people are advised to talk to their doctor before taking creatine supplements. According to the University of Maryland Medical Center, creatine can cause mild side effects.
Potential side effects of creatine include:
- Stomach pain
- Muscle cramping
In addition, patients with kidney disease should completely avoid using creatine, and caution is advised for people with diabetes and anyone taking blood sugar supplements.
Overall, creatine seems to be relatively safe. The authors of a review titled "Creatine supplementation and exercise performance" concluded:
"[Creatine supplementation] appears to pose no serious health risks when taken at doses described in the literature and may enhance exercise performance in individuals that require maximal single effort and/or repetitive sprint bouts."
However, because creatine is a bioactive substance, it should be approached with caution. The Mayo Clinic confirms that "[c]reatine is likely safe when used long-term," but they also make it clear that certain individuals may not be best advised to take creatine without consulting a doctor.
According to the Mayo Clinic, creatine might lower blood glucose; this could be significant for individuals with diabetes or hypoglycemia. Creatine may also raise blood pressure, so for those already taking medication to raise blood pressure, or for anyone with hypertension, this should be noted.
Among other conditions, they advise caution for: "people with deep vein thrombosis, electrolyte disorders or imbalances, gastrointestinal disorders, irregular heartbeat, kidney stones, liver disease, migraines, musculoskeletal disorders, neurological dysfunction, neuromuscular disorders, orthostatic hypotension (low blood pressure upon standing) [...] psychiatric disorders, seizures, skin disorders, and athletes who may combine dehydration regimens (diuretics, sweating)."