Creatine Monohydrate

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Creatine (creatine monohydrate) is a colourless, crystalline substance used in muscle tissue for the production of phosphocreatine, an important factor in the formation of adenosine triphosphate (ATP), the source of energy for muscle contraction and many other functions in the body.1 2

Where is it found?

Creatine is produced naturally in the human liver, pancreas, and kidneys. It is concentrated primarily in muscle tissues, including the heart. Animal proteins, including fish, are the main source of the 1–2 grams per day of dietary creatine most people consume. Supplements in the form of creatine monohydrate are well absorbed and tolerated by the stomach.

Creatine monohydrate has been used in connection with the following conditions (refer to the individual health concern for complete information):

Science Ratings Health Concerns
3Stars

Athletic performance (for high-intensity, short duration exercise or sports with alternating low- and high-intensity efforts)
2Stars

Athletic performance (for non-weight bearing endurance exercise)

Chronic obstructive pulmonary disease
1Star

Congestive heart failure

High cholesterol

High triglycerides

Muscular dystrophy
3Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star For a herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.
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Who is likely to be deficient?

People involved in intense physical activity, especially those limiting their intake of red meat, may have low muscle stores of creatine. A few muscle diseases, as well as rheumatoid arthritis, and chronic circulatory and respiratory diseases, are associated with lowered creatine levels.3

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How much is usually taken?

Two methods are used for supplementing with creatine. In the loading method, 20 grams of creatine per day (in four divided amounts mixed well in warm liquid) are taken for five to six days.4 Muscle creatine levels increase rapidly, which is beneficial if a short-term rise in force is needed, such as during a weight-lifting competition, football game, or sprinting. To maintain muscle creatine levels after this loading period, 2–10 grams per day may be effective.5 6

In another method, 3 grams of creatine monohydrate per day are taken over an extended training period of at least four weeks, during which muscle creatine levels rise more slowly, eventually reaching levels similar to those achieved with the loading method.7 However, no trials testing exercise performance changes have been done using this method. Taking creatine with sugar appears to maximise muscle uptake.8 9

Caffeine intake should not be excessive, as large amounts may counteract the benefits of creatine supplementation.10

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Are there any side effects or interactions?

Little is known about long-term side effects of creatine, but no consistent toxicity has been reported in studies of creatine supplementation. In a study of side effects of creatine, diarrhoea was the most commonly reported adverse effect of creatine supplementation, followed by muscle cramping.11 Some reports showed that kidney, liver, and blood functions were not affected by short-term higher amounts12 13 or long-term lower amounts 14 15 of creatine supplementation in healthy young adults. In a small study of people taking 5–30 grams per day, no change in kidney function appeared after up to five years of supplementation.16 However, interstitial nephritis, a serious kidney condition, developed in an otherwise healthy young man, supplementing with 20 grams of creatine per day.17 Improvement in kidney function followed avoidance of creatine. Details of this case strongly suggest that creatine supplementation triggered this case of kidney disease. Creatine supplementation may also be dangerous for people with existing kidney disease. In one report, a patient with nephrotic syndrome (a kidney disorder) developed glomerulosclerosis (another serious kidney condition) while taking creatine. when the creatine was discontinued, the glomerulosclerosis resolved.18

Muscle cramping after creatine supplementation has been anecdotally reported in three studies.19 20 21

At the time of writing, there were no well-known drug interactions with creatine monohydrate.

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References
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