Creatine

Athletic performance

Most human studies have taken place in laboratories, not in people actually playing sports. Preliminary studies show that creatine supplements improve strength and lean muscle mass during high-intensity, short-duration exercises, such as weight lifting. In these studies, the positive results were seen mainly in young people, around 20 years old. Researchers aren't clear on how creatine supplementation improves performance. But it may allow the body to use fuel more efficiently during exercise and increase muscle production. More research is needed.

Creatine does not seem to improve performance in exercises that requires endurance, like running, or in exercise that isn't repeated, although study results are mixed.

Creatine is not banned by the National Collegiate Athletic Association (NCAA) or the International Olympic Committee, but using it for athletic performance is controversial. The NCAA prohibits its member schools from giving creatine and other muscle-building supplements to athletes, although it doesn't ban athletes from using it.

Creatine appears to be generally safe, although when it is taken at high doses there is the potential for serious side effects, such as kidney damage. High doses may also stop the body from making its own creatine.

Some creatine supplements may be marketed directly to teens, claiming to help them change their bodies without exercising. However, one survey conducted with college students found that teen athletes frequently exceed the recommended loading and maintenance doses of creatine. Creatine has not been tested to determine whether it is safe or effective in people under 19.

Heart disease

Preliminary studies suggest that creatine supplements may help lower levels of triglycerides (fats in the blood) in men and women with high concentrations of triglycerides.

In a few studies of people with heart failure, those who took creatine in addition to receiving standard medical care, increased the amount of exercise they could do before becoming fatigued, compared to those who took placebo. Getting tired easily is one of the major symptoms of heart failure. One study of 20 people with heart failure found that short-term creatine supplementation in addition to standard medication helped to increase body weight and improved muscle strength. Other studies, however, showed no improvement.

Creatine has also been reported to help lower levels of homocysteine. Homocysteine is associated with heart disease, including heart attack and stroke.

Cancer

Preliminary studies suggest that creatine may have anticancer properties.

Chronic Obstructive Pulmonary Disease (COPD)

One study found that people with COPD who took creatine increased muscle mass, muscle strength and endurance, and improved their health status compared with those who took placebo. They did not increase their exercise capacity. More research is needed.

Muscular dystrophy

People who have muscular dystrophy may have less creatine in their muscle cells, which may contribute to muscle weakness. One study found that taking creatine led to a small improvement in muscle strength. However, other studies found no effect.

Parkinson disease

People with Parkinson disease (PD) have decreased muscular fitness, including decreased muscle mass, muscle strength, and increased fatigue. One study found that giving creatine to people with PD improved their exercise ability and endurance. In another study, creatine supplements boosted participants' moods and reduced their need for medication compared to those who didn't take creatine. However, other studies suggest combining creatine and caffeine (i.e. taking / ingesting both) could make PD worse. More research is needed.

Amyotrophic Lateral Sclerosis (ALS or Lou Gehrig's disease)

Creatine appears to slow the progression of ALS and improves patients' quality of life. More research is needed.

About half of the creatine in our bodies is made from amino acids in the liver, kidney, and pancreas. The other half comes from foods we eat. Wild game is considered to be the richest source of creatine. But lean red meat and fish (particularly herring, salmon, and tuna) are also good sources.

Supplements are commonly sold as powders. But liquids, tablets, capsules, energy bars, fruit-flavored chews, drink mixes, and other preparations are also available.

Pediatric

Creatine supplements are not recommended for children or teens.

Adult

Sample doses are below. You should ask your doctor to help determine the right dose for you.

An example of a typical loading dose in exercise performance (for adults ages 19 and older): Take 5 g of creatine monohydrate, 4 times daily (20 g total daily) for 2 to 5 days maximum.

Maintenance dose in exercise performance (for adults ages 19 and older): Take 2 g daily.

Your body may absorb creatine better when you take it with carbohydrates, such as fruits, fruit juices, and starches. The doses listed have been tested frequently in athletes. It's not known whether these dosages have the same effects in non-athletes.

Because of the potential for side effects and interactions with medications, you should take dietary supplements only under the supervision of a knowledgeable health care provider.

Side effects of creatine include:

• Weight gain
• Muscle cramps
• Muscle strains and pulls
• Stomach upset
• Diarrhea
• Dizziness
• High blood pressure
• Liver dysfunction
• Kidney damage

Most studies have found no significant side effects at the doses used for up to 6 months.

Rhabdomyolysis (breakdown of skeletal muscle tissue) and sudden kidney failure was reported in one case involving an athlete taking more than 10 grams daily of creatine for 6 weeks.

People with kidney disease, high blood pressure, or liver disease should not take creatine.

Taking creatine supplements may stop the body from making its own natural stores, although researchers don't know what the long-term effects are. The Food & Drug Administration recommends talking to your doctor before starting to take creatine.

There have been reports of contaminated creatine supplements. Be sure to buy products made by established companies with good reputations.

Some doctors think creatine may cause an irregular heartbeat or a skin condition called purpuric dermatosis in some people. More research is needed to know for sure.

If you are being treated with any of the following medications, you should not use creatine without talking to your doctor first.

Non steroidal anti-inflammatory drugs (NSAIDs)

Taking creatine with these pain relievers may increase the risk of kidney damage. NSAIDs include ibuprofen (Motrin, Advil) and naproxen (Aleve).

Caffeine

Caffeine may make it hard for your body to use creatine, and taking creatine and caffeine may increase the risk of dehydration. Using creatine, caffeine, and ephedra (now banned in the U.S.) may increase the risk of stroke.

Diuretics (water pills)

Taking creatine with diuretics may increase the risk of dehydration and kidney damage.

Cimetidine (Tagamet)

Taking creatine while taking Tagamet may increase the risk of kidney damage.

Drugs that affect the kidneys

Using creatine along with any medication that affects the kidneys may raise the risk of kidney damage.

Probenecid

Taking creatine while taking probenecid, a drug used to treat gout, may increase the risk of kidney damage.

Adhihetty PJ, Beal MF. Creatine and its potential therapeutic value for targeting cellular energy impairment in neurodegenerative diseases. Neuromolecular Med. 2008;10(4):275-90. Epub 2008 Nov 13. Review.

Aguiar AF, Januario RS, Junior RP, et al. Long-term creatine supplementation improves muscular performance during resistance training in older women. Eur J Appl Physiol. 2013;113(4):987-996.

Beck TW, Housh TJ, Johnson GO, Coburn JW, Malek MH, Cramer JT. Effects of a drink containing creatine, amino acids, and protein combined with ten weeks of resistance training on body composition, strength, and anaerobic performance. J Strength Cond Res. 2007;21(1):100-104.

Bender A, Koch W, Elstner M, et al. Creatine supplementation in Parkinson disease: a placebo-controlled randomized pilot trial. Neurology. 2006;67(7):1262-1264.

Bender A, Samtleben W, Elstner M, Klopstock T. Long-term creatine supplementation is safe in aged patients with Parkinson disease. Nutr Res. 2008;28(3):172-178.

Benzi G. Is there a rationale for the use of creatine either as nutritional supplementation or drug administration in humans participating in a sport? Pharmacol Res. 2000;41(3):255-264.

Cancela P, Ohanian C, Cuitiño E, Hackney AC. Creatine supplementation does not affect clinical health markers in football players. Br J Sports Med. 2008;42(9):731-735.

Candow DG, Vogt E, Johannsmeyer S, Forbes SC, Farthing JP. Strategic creatine supplementation and resistance training in healthy older adults. Appl Physiol Nutr Metab. 2015;40(7):689-694.

Carvalho AP, Rassi S, Fontana KE, Correa Kde S, Feitosa RH. Influence of creatine supplementation on the functional capacity of patients with heart failure. Arq Bras Cardiol. 2012;99(1):623-629.

Chilibeck PD, Chrusch MJ, Chad KE, Shawn Davison K, Burke DG. Creatine monohydrate and resistance training increase bone mineral content and density in older men. J Nutr Health Aging. 2005;9(5):352-353.

Cornelissen VA, Defoor JG, Stevens A, et al. Effect of creatine supplementation as a potential adjuvant therapy to exercise training in cardiac patients: a randomized controlled trial. Clin Rehabil. 2010;24(11):988-999.

Cornish SM, Candow DG, Jantz NT, et al. Conjugated linoleic acid combined with creatine monohydrate and whey protein supplementation during strength training. Int J Sport Nutr Exerc Metab. 2009;19(1):79-96.

Deldicque L, Francaux M. Functional food for exercise performance: fact or foe? Curr Opin Clin Nutr Metab Care. 2008;11(6):774-781. Review.

Eckerson JM, Stout JR, Moore GA, et al. Effect of creatine phosphate supplementation on anaerobic working capacity and body weight after two and six days of loading in men and women. J Strength Cond Res. 2005;19(4):756-763.

Groeneveld GJ, Beijer C, Veldink JH, Kalmijn S, Wokke JH, van den Berg LH. Few adverse effects of long-term creatine supplementation in a placebo-controlled trial. Int J Sports Med. 2005;26(4):307-313.

Gualano B, de Salles Painelli V, Roschel H, et al. Creatine supplementation does not impair kidney function in type 2 diabetic patients: a randomized, double-blind, placebo-controlled, clinical trial. Eur J Appl Physiol. 2011;111(5):749-756.

Hass CJ, Collins MA, Juncos JL. Resistance training with creatine monohydrate improves upper-body strength in patients with Parkinson disease: a randomized trial. Neurorehabil Neural Repair. 2007;21(2):107-115.

Kingsley M, Cunningham D, Mason L, Kilduff LP, McEneny J. Role of creatine supplementation on exercise-induced cardiovascular function and oxidative stress. Oxid Med Cell Longev. 2009;2(4):247-254.

Kley RA, Tarnopolsky MA, Vorgerd M. Creatine for treating muscle disorders. Cochrane Database Syst Rev. 2013;(6):CD004760.

Korzun WJ. Oral creatine supplements lower plasma homocysteine concentrations in humans. Clin Lab Sci. 2004;17(2):102-106.

McMorris T, Harris RC, Swain J, et al. Effect of creatine supplementation and sleep deprivation, with mild exercise, on cognitive and psychomotor performance, mood state, and plasma concentrations of catecholamines and cortisol. Psychopharmacology (Berl). 2006;185(1):93-103.

Metzl JD, Small E, Levine SR. Gershel JC. Creatine use among young athletes. Pediatrics. 2001;108(2):421-425.

Patra S, Ghosh A, Roy SS, et al. A short review on creatine-creatine kinase system in relation to cancer and some experimental results on creatine as adjuvant in cancer therapy. Amino Acids. 2012;42(6):2319-2330.

Persky AM, Rawson ES. Safety of creatine supplementation. Subcell Biochem. 2007;46:275-289. Review.

Sheth NP, Sennett B, Berns JS. Rhabdomyolysis and acute renal failure following arthroscopic knee surgery in a college football player taking creatine supplements. Clin Nephrol. 2006;65(2):134-137.

Simon DK, Wu C, Tilley BC, et al. Caffeine and progression of Parkinson disease: a deleterious interaction with creatine. Clin Neuropharmacol. 2015;38(5):163-169.

Sullivan PG, Geiger JD, Mattson MP, Scheff SW. Dietary supplement creatine protects against traumatic brain injury. Ann Neurol. 2000;48(5):723-729.

Tarnopolsky MA, Beal MF. Potential for creatine and other therapies targeting cellular energy dysfunction in neurological disorders [Review]. Ann Neurol. 2001;49(5):561-574.

Tyler TF, Nicholas SJ, Hershman EB, Glace BW, Mullaney MJ, McHugh MP. The effect of creatine supplementation on strength recovery after anterior cruciate ligament (ACL) reconstruction: a randomized, placebo-controlled, double-blind trial. Am J Sports Med. 2004;32(2):383-388.

Willer B, Stucki G, Hoppeler H, Bruhlmann P, Krahenbuhl S. Effects of creatine supplementation on muscle weakness in patients with rheumatoid arthritis. Rheumatology. 2000;39(3):293-298.

Witte KK, Clark AL, Cleland JG. Chronic heart failure and micronutrients. J Am Coll Cardiol. 2001;37(7):1765-1774.