Common Names

  • Beta-hydroxymethylbutyrate
  • beta-hydroxy-beta-methylbutyrate monohydrate

For Patients & Caregivers

HMB has not been shown to treat or prevent cancer.

HMB is a breakdown product of the amino acid leucine. It and other amino acids (such as arginine and glutamine) are generally known to prevent or slow the damage to muscle cells that occurs with intense exercise or in advanced cancer and AIDS. HMB has been shown to increase muscle health, strength, and function in elderly female patients. It also helps to prevent muscle breakdown in elderly bedridden nursing home patients receiving tube feedings. In studies in both animals and healthy volunteers, HMB caused a decrease in total cholesterol and LDL (“bad”) cholesterol. Scientists are not exactly certain how HMB exerts these effects. HMB does not affect blood levels of testosterone or growth factors.

  • To prevent or reverse weight loss (cachexia) and weakness associated with diseases such as cancer and AIDS
    Two small clinical trials support this use, but larger trials that follow patients for longer periods of time are needed.
  • To increase muscle mass
    Clinical trials show mixed results regarding this use. The results of one small study found that HMB may decrease muscle breakdown in bed-ridden elderly patients. Another small study found that a formula containing HMB, arginine, lysine, and ascorbic acid may improve muscle strength, health, and function in elderly women. However, further study is needed to confirm these effects.
  • To improve strength and endurance in athletes
    Clinical trials show mixed results regarding this use.

Chronic supplementation of HMB resulted in hyperinsulinemia (high insulin levels in the blood) in rats.

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For Healthcare Professionals


Beta-hydroxy-beta-methylbutyrate (HMB) is a metabolite of the amino acid leucine. Patients use HMB for body strength, muscle gain, AIDS wasting, and cancer-related cachexia.

Clinical studies suggest that HMB increases lean weight gain and reduces adipose tissue (1) (2). It does not increase muscle strength (3) nor affect plasma levels of androgens, cortisol, or insulin (4), but improves some components of aerobic performance (5). HMB was shown to reduce muscle breakdown in bed-ridden elderly patients fed by nasogastric tube (9) . A formulation containing HMB, arginine, and lysine significantly improved muscle strength, health and function in elderly women (10) .
Conclusions of a systematic review indicate that HMB is effective in preventing exercise-related muscle damage in healthy trained and untrained individuals, as well as muscle loss during chronic disease (17). Data also indicate that HMB supplementation may improve pulmonary function in patients with chronic obstructive pulmonary disease (COPD), (11) and nitrogen balance in critically injured patients (12)

HMB may be of benefit in AIDS wasting (6), but additional research is necessary concerning use for cancer-related cachexia (7). A large randomized clinical study of HMB in patients with cancer cachexia failed to demonstrate a significant effect (8). However, supplementation with a combination of beta-hydroxy-beta-methylbutyrate, arginine and glutamine was effective in preventing radiation dermatitis in a study of head and neck cancer patients (18).

  • Cancer-related cachexia
  • HIV- and AIDS-associated wasting
  • Strength and stamina
  • Weight gain

In muscle cells, HMB is thought to restore the balance between intracellular protein synthesis and proteolysis, likely by activating the PI3K/Akt-dependent mammalian target of rapamycin (mTOR) and FoxO1/FoxO3a signaling pathway and the reduction of tumor necrosis factor alpha-interferon gamma-induced MuRF-1 expression, improving atrophy due to aging (19).

In animal models, HMB caused reductions in the total subcutaneous fat content and LDL cholesterol (15). But it did not affect circulating plasma levels of testosterone (4), cortisol, insulin-like growth factor-1 (IGF-1), or insulin (14). Supplemental HMB has been shown to enhance protein synthesis in skeletal muscle of neonatal pigs by stimulating translation initiation (20).

In a study of mice, HMB blocked sepsis-induced caspase 3, 20S proteasomal and PKR activation, and significantly attenuated diaphragm weakness, preserving the generation of muscle force. This may potentially be of use in infected patients by reducing the duration of mechanical ventilation and decreasing mortality (21). HMB was also shown to improve the proliferation of muscle stem cells in fast twitch plantaris muscles in aged rats. This is thought to be due to reduced apoptotic index in HMB treated muscles associated with enhanced satellite cell proliferation leading to increased differentiated myonuclei (22).

Chronic supplementation of HMB resulted in hyperinsulinemia in rats (16).

May reduce Low-density lipoprotein.

  1. Gallagher PM, et al. Beta-hydroxy-beta-methylbutyrate ingestion, part I: effects on strength and fat free mass. Med Sci Sports Exerc. 2000;32:2109-15.
  2. Vukovich MD, et al. Beta-hydroxy-beta-methylbutyrate (HMB) kinetics and the influence of glucose ingestion in humans. J Nutr Biochem. 2001;12:631-9.
  3. O’Connor DM, Crowe MJ. Effects of six weeks of beta-hydroxy-beta-methylbutyrate (HMB) and HMB/creatine supplementation on strength, power, and anthropometry of highly trained athletes. J Strength Cond Res. 2007;21(2):419-23.
  4. Slater GJ, et al. Beta-hydroxy beta-methylbutyrate (HMB) supplementation does not influence the urinary testosterone: epitestosterone ratio in healthy males. J Sci Med Sport. 2000;3:79-83.
  5. Lamboley CR, Royer D, Dionne IJ. Effects of beta-hydroxy-beta-methylbutyrate on aerobic-performance components and body composition in college students. Int J Sport Nutr Exerc Metab. 2007 Feb;17(1):56-69.
  6. Clark RH, et al. Nutritional treatment for acquired immunodeficiency virus-associated wasting using beta-hydroxy-beta-methylbutyrate, glutamine, and arginine: a randomized, double-blind, placebo-controlled study. J Parenteral Enteral Nutr. 2000;24:133-9.
  7. May PE, et al. Reversal of cancer-related wasting using oral supplementation with a combination of beta-hydroxy-beta-methylbutyrate, arginine, and glutamine. Am J Surgery. 2002;183:471-479.
  8. Berk L, James J, Schwartz A, et al. A randomized, double-blind, placebo-controlled trial of a beta-hydroxyl beta-methyl butyrate, glutamine, and arginine mixture for the treatment of cancer cachexia. Support Care Cancer. 2008 Oct;16(10):1179-88.
  9. Hsieh LC, Chow CJ, Chang WC, et al. Effect of beta-hydroxy-beta-methylbutyrate on protein metabolism in bed-ridden elderly receiving tube feeding. Asia Pac J Clin Nutr. 2010;19(2):200-8.
  10. Flakoll P, Sharp R, Baier S, et al. Effect of beta-hydroxy-beta-methylbutyrate, arginine, and lysine supplementation on strength, functionality, body composition, and protein metabolism in elderly women. Nutrition. 2004 May;20(5):445-51.
  11. Hsieh LC, Chien SL, Huang MS, et al. Anti-inflammatory and anticatabolic effects of short-term beta-hydroxy-beta-methylbutyrate supplementation on chronic obstructive pulmonary disease patients in intensive care unit. Asia Pac J Clin Nutr. 2006;15(4):544-50.
  12. Kuhls DA, Rathmacher JA, Musngi MD, et al. Beta-hydroxy-beta-methylbutyrate supplementation in critically ill trauma patients. J Trauma. 2007;62(1):125-31.
  13. Slater GJ, Jenkins D. Beta-hydroxy-beta-methylbutyrate (HMB) supplementation and the promotion of muscle growth and strength. Sports Med. 2000;30:105-16.
  14. Gallagher PM, et al. Beta-hydroxy-beta-methylbutyrate ingestion, part II: effects on hematology, hepatic and renal function. Med Sci Sports Exerc. 2000;32:2116-9.
  15. Nissen S, et al. Beta-hydroxy-beta-methylbutyrate (HMB) supplementation in humans is safe and may decrease cardiovascular risk. J Nutr. 2000;130:1937-45.
  16. Gerlinger-Romero F, Guimarães-Ferreira L, Giannocco G, Nunes MT. Chronic supplementation of beta-hydroxy-beta methylbutyrate (HMβ) increases the activity of the GH/IGF-I axis and induces hyperinsulinemia in rats. Growth Horm IGF Res. 2011 Apr;21(2):57-62.
  17. Molfino A, Gioia G, Rossi Fanelli F, Muscaritoli M. Beta-hydroxy-beta-methylbutyrate supplementation in health and disease: a systematic review of randomized trials. Amino Acids. 2013 Dec;45(6):1273-92.
  18. Imai T, Matsuura K, Asada Y, et al. Effect of HMB/Arg/Gln on the prevention of radiation dermatitis in head and neck cancer patients treated with concurrent chemoradiotherapy. Jpn J Clin Oncol. 2014 May;44(5):422-7.
  19. Kimura K, Cheng XW, Inoue A, Hu L, Koike T, Kuzuya M. β-Hydroxy-β-methylbutyrate facilitates PI3K/Akt-dependent mammalian target of rapamycin and FoxO1/3a phosphorylations and alleviates tumor necrosis factor α/interferon γ-induced MuRF-1 expression in C2C12 cells. Nutr Res. 2014 Apr;34(4):368-74.
  20. Wheatley SM, El-Kadi SW, Suryawan A, et al. Protein synthesis in skeletal muscle of neonatal pigs is enhanced by administration of β-hydroxy-β-methylbutyrate. Am J Physiol Endocrinol Metab. 2014 Jan 1;306(1):E91-9.
  21. Supinski GS, Callahan LA. β-hydroxy-β-methylbutyrate (HMB) prevents sepsis-induced diaphragm dysfunction in mice. Respir Physiol Neurobiol. 2014 Jun 1;196:63-8.
  22. Alway SE, Pereira SL, Edens NK, Hao Y, Bennett BT. β-Hydroxy-β-methylbutyrate (HMB) enhances the proliferation of satellite cells in fast muscles of aged rats during recovery from disuse atrophy. Exp Gerontol. 2013 Sep;48(9):973-84.
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