Creatine Monohydrate Information and Effects

Creatine monohydrate, also known as creatine, is a colorless, crystalline compound used for the production of phosphocreatine, important to formation of adenosine triphosphate (ATP), the source of energy for muscle contraction and many other functions in the body.

Up to 2,000 mg (2 grams) of creatine are produced every day in the body by the kidneys and liver. Another 1,000 to 2,000 mg (one to 2 grams) per day comes from the diet. Creatine concentrates mostly in the large skeletal muscles, where it is involved in producing energy and moderating muscle fatigue. Most adult humans store about 120,000 mg (120 grams) of creatine and use about 2,000 mg (2 grams) every day. However, it is believed that muscle stores of creatine are decreased dramatically during the first few seconds of exercise and that intensive exercise uses up creatine at very fast rates. After physical activity is halted, creatine stores gradually replenish over several minutes. Creatine supplementation may increase the amount of creatine reserve up to 140,000 to 150,000 mg (140 to 150 grams), but any excess creatine is lost in the urine.

Studies indicate that creatine supplementation by body builders and athletes may increase gains in lean body mass, although exactly how much is gained is still unclear. Some evidence indicates 20 grams per day of creatine taken for 5 to 6 days may improve physical performance and delay muscle fatigue during short, high-intensity work outs such as weight lifting or sprinting. These findings do not appear to hold true for the elderly who experience only minimal gains, if any, from using creatine supplements.

There is also some very preliminary data showing that creatine may be helpful when used in connection with muscular dystrophy and amyotrophic lateral scleroses and may improve skeletal muscle function in some with congestive heart failure and gyrate atrophy of the retina. Creatine has inhibited the growth of some solid tumors in rats, but no human cancer data exists.

Creatine Side Effects

In a study of side effects of creatine, diarrhea was the most commonly reported adverse effect of creatine supplementation, followed by muscle cramping. Weight gain may occur from water retention. During a five day loading period, weight gains of 1.1 to 3.5 pounds have been reported. There are reports of elevated serum creatinine, a metabolite of creatine and a marker of kidney function, in some who take creatine and have normal renal function. This is reversible upon discontinuation of creatine.

Little is known about the long-term affects of creatine usage. Many people do not experience any adverse short-term side effects from using creatine. Most side effects experienced are reversible upon discontinuation of creatine.


Creatine is available in a number of oral dose forms with the most reliably consistent being capsules and powders that are usually added to water, low-acid fruit juice (such as apple, grape, pineapple, or tomato juice), or a sports drink that contains carbohydrates. Some research suggests that taking creatine with carbohydrates improves the absorption of creatine. Fruit juices with high acid contents (grapefruit, orange, and other citrus fruit juices) may interfere with the body's absorption of supplemental creatine. One teaspoon of most creatine powders supplies about 5,000 mg (5 grams).

Dosing for creatine varies depending on the desired effect. One common recommendation for enhancing exercise capability is to take a high dose of creatine - 20,000 mg (20 grams or about 4 teaspoons) per day for the first 2 to 7 days and then reduce the daily dose to 2,000 mg (2 grams). Similar results have been seen with a dose of 3,000 mg (3 grams) every day. Usually, daily amounts of creatine are divided into two doses that are taken 10 to 12 hours apart. Taking commercially-packaged liquid forms of creatine are not recommended due to the likelihood that creatine breaks down in solution.