Creatine

Follow all directions on the product label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Creatine can cause kidney damage when used over a long period or if your daily doses are too high.

Creatine is a manmade form of a chemical that is normally found in the body. Creatine is also found in meat and fish. Most creatine in the human body is stored in the muscles. Creatine is a source of energy for muscle contraction and is also involved in muscle growth.

Creatine has been used in alternative medicine as a possibly effective aid for enhancing athletic performance, and for increasing muscle strength in people with heart failure, muscular dystrophy, and McArdle's disease (a genetic disorder). Creatine may also be possibly effective in treating Parkinson's disease, and gyrate atrophy (a genetic eye disorder that affects the retina and causes vision loss).

Creatine has also been used to treat rheumatoid arthritis, or Lou Gehrig's disease (ALS). However, research has shown that creatine may not be effective in treating these conditions.

Other uses not proven with research have included treating high cholesterol, depression, bipolar disorder, or certain muscle diseases.

It is not certain whether creatine is effective in treating any medical condition. Medicinal use of this product has not been approved by the FDA. Creatine should not be used in place of medication prescribed for you by your doctor.

Creatine is often sold as an herbal supplement. There are no regulated manufacturing standards in place for many herbal compounds and some marketed supplements have been found to be contaminated with toxic metals or other drugs. Herbal/health supplements should be purchased from a reliable source to minimize the risk of contamination.

Creatine may also be used for purposes not listed in this product guide.

Follow all directions on the product label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

You should not use this product if you have:

• kidney disease; or
• diabetes.

Ask a doctor, pharmacist, or other healthcare provider if it is safe for you to use this product if you have:

• heart disease.

Creatine may not be as effective in improving strength or building muscle in people over 60 years old.

It is not known whether creatine will harm an unborn baby. Do not use this product if you are pregnant.

Creatine may pass into breast milk and may harm a nursing baby. Do not use this product if you are breast-feeding a baby.

Do not give any herbal/health supplement to a child without medical advice.

Creatine has not been evaluated by the FDA for safety, effectiveness, or purity. All potential risks and/or advantages of this medication may not be known. Additionally, there are no regulated manufacturing standards in place for these compounds. There have been instances where herbal/health supplements have been sold which were contaminated with toxic metals or other drugs. Herbal/health supplements should be purchased from a reliable source to minimize the risk of contamination.

Drink plenty of fluid while taking creatine. Although it has not been proven, dehydration, heat-related illnesses, muscle cramps, reduced blood volume, and electrolyte imbalances are expected to be more likely to occur while taking creatine.

Follow all directions on the product label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

You should not use creatine if you have:

• kidney disease; or

• diabetes.

Ask a doctor, pharmacist, or other healthcare provider if it is safe for you to use this product if you have:

• heart disease.

Creatine may not be as effective in improving strength or building muscle in people over 60 years old.

It is not known whether creatine will harm an unborn baby. Do not use this product if you are pregnant.

Creatine may pass into breast milk and may harm a nursing baby. Do not use this product if you are breast-feeding a baby.

Do not give any herbal/health supplement to a child without medical advice.

None well documented.

Most reports of adverse reactions remain anecdotal because they lack documentation in well-controlled trials. The only well-documented adverse reaction is an increase in body mass. Anecdotal reports include minor GI upset, dehydration, heat-related illnesses, reduced blood volume, electrolyte imbalances, and muscle cramping.

Research reveals little or no information regarding toxicology with the use of this product.

Creatine is acquired exogenously through the diet or is endogenously synthesized in the body. It is a constituent of muscle tissue and occurs naturally in meat, fish, and other animal products, with trace amounts found in milk and some plants. Herring contains 6.5 to 10 g/kg of creatine, while beef, pork, salmon, and tuna all contain approximately 4 to 5 g/kg. 3 A typical American/Western diet provides 1 to 2 g/day; vegetarians consume much less and thus, their daily creatine needs are met completely via endogenous synthesis. 2 , 3 , 4 , 5 Endogenous creatine is synthesized from arginine and glycine by 2 enzymatic reactions; in the kidney, guanidinoacetic acid is produced and upon transfer to the liver, is methylated using methionine to form creatine. This process produces approximately 1 to 2 g/day of creatine. 6 Creatine is then transported via circulation to various tissues, in particular skeletal muscle, for utilization. 1 , 3 , 7

The majority of studies evaluating the effects of oral creatine supplementation have been conducted using creatine monohydrate powder. The effects of other supplement formulations, such as creatine citrate or creatine phosphate, have not been determined. Creatine monohydrate is available in several dose forms, including bar, candy, capsules, gel, gum, liquid, and powder. 8 The efficacy of some of these dose forms has not been demonstrated.

Creatine was discovered in 1832 by the French chemist Michel Chevreul as an organic constituent of meat. Muscle work was later associated with creatine in 1847 when it was observed that the flesh of wild foxes killed in the chase contained 10 times more creatine than those living in captivity. 3 In 1911, creatine was reported to be involved in muscle metabolism; it was demonstrated that oxygen consumption could be stimulated by adding creatine to muscle mince. In the early 1930s, it was suggested that creatine phosphate might serve as the source of energy for muscle contraction when its large free energy of hydrolysis (12 kcal/mol) was identified. By 1939, oxygen consumption was shown to be coupled to creatine phosphate synthesis in muscle, which confirmed that oxidative phosphorylation was indeed a function of creatine. 7

In the late 1960s, researchers began using needle biopsy techniques to study the breakdown and resynthesis of adenosine triphosphate (ATP) and creatine phosphate with exercise. It was not until the early 1990s that creatine's influence on exercise performance in humans began to be studied. Reports followed in 1992 of a 20% increase in human muscle mass subsequent to creatine supplementation. 3 , 9 Numerous studies have since been conducted in untrained or moderately trained subjects in the laboratory setting to determine the potential ergogenic value of creatine supplementation. 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 Benefit has extended beyond simple laboratory exercises, with enhanced sprint and weight-lifting performance reported in elite athletes. 10 , 21 , 22 , 23 , 27

Creatine has been widely studied as an athletic supplement, in Huntington disease, and in muscular dystrophies. Oral doses range from 2 to 35 g daily, 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 usually 20 g/day for up to 1 week for loading doses and 5 g/day for maintenance doses. 110 The observed safe-level risk assessment method indicates that safety evidence is strong at intakes of up to 5 g/day for chronic supplementation. 111 Much higher levels have been used without adverse reactions and may be safe, but long-term safety data are lacking. 111