Vitamins, Minerals and Dietary Supplements
What is HMB?
HMB is short for hydroxyl-beta-methylbultyrate. It is a derivative of leucine, an essential amino acid, and is also present in some foods.
Research suggests that HMB plays a role in the synthesis of proteins, including the protein used to build new muscle tissue. A study published in 1996 showed that weightlifters who took three grams of HMB per day showed greater gains in muscle mass and strength over a seven-week period compared to people who took no supplements. However, other studies have shown that HMB does not contribute to increased athletic performance or changes in body composition.
In addition to muscle tissue, evidence suggests that HMB can help contribute to the loss of body fat and control weight. Further studies need to be conducted to verify these results, however.
How much HMB should I take?
The amount of HMB to be taken depends on the condition being treated. Most studies that have examined the effectiveness of HMB have used doses of three grams per day, usually in combination with exercise. Other studies have used weight-specific doses of HMB, in the amount of 17 milligrams per pound of body weight per day.
What forms of HMB are available?
Small amounts of HMB are present in some foods, particularly alfalfa and catfish. HMB is also produced in the body as a derivative of the amino acid leucine. In addition, HMB supplements are available at many health food stores, usually as capsules or tablets.
What can happen if I take too much HMB? Are there any interactions I should be aware of? What precautions should I take?
As of this writing, there are no known side-effects associated with HMB, nor are there any well-known drug interactions. As always, make sure to consult with a licensed health care provider before taking HMB or any other herbal remedy or dietary supplement.
- Gallagher PM, Carrithers JA, Godard MP, et al. Beta-hydroxy-beta-methylbutyrate ingestion, Part I: effects on strength and fat free mass. Med Sci Sports Exerc 2000;32:2109-15.
- Nissen S, Panton L, Wilhelm R, et al. Effect of beta-hydroxy-beta-methylbutyrate (HMB) supplementation on strength and body composition of trained and untrained males undergoing intense resistance training. FASEB J 1996;10:A287.
- Nissen S, Sharp R, Ray M, et al. Effect of leucine metabolite beta-hydroxy-beta-methylbutyrate on muscle metabolism during resistive-exercise training. J Appl Physiol 1996;81:2095-104.
- Slater G, Jenkins D, Logan P, et al. Beta-hydroxy-beta-methylbutyrate (HMB) supplementation does not affect changes in strength or body composition during resistance training in trained men. Int J Sport Nutr Exerc Metab 2001;11:384-96.
- Slater GJ, Jenkins D. Beta-hydroxy-beta-methylbutyrate (HMB) supplementation and the promotion of muscle growth and strength. Sports Med 2000;30:105-16.