Overview
Beta-Hydroxy-Beta-Methylbutyrate (HMB) is a metabolite of the branched-chain amino acid leucine that plays a role in promoting muscle protein synthesis and reducing muscle protein breakdown. It is commonly used as a supplement to support muscle mass, strength, and recovery, particularly in populations experiencing muscle loss or undergoing physical stress. Research shows HMB supplementation can significantly improve muscle mass, strength, and physical performance in older adults with sarcopenia [9] and reduce muscle loss in aging populations [10]. In critically ill patients, such as those with COPD in intensive care, short-term HMB supplementation demonstrates anti-inflammatory and anticatabolic effects, improving protein metabolism and clinical outcomes [6]. However, evidence for ergogenic benefits in healthy, trained individuals is less consistent, with no significant improvements in strength or body composition observed in resistance-trained men [4] or collegiate athletes [5]. A recent meta-analysis found limited evidence for HMB improving endurance performance or VO₂ max in healthy individuals [1]. Overall, the most consistent benefits are seen in clinical or aging populations with muscle wasting conditions.
Dosage Guide
Therapeutic Doses
For treatment of specific conditions
Special Forms
Alternative forms for specific needs
Most common supplemental form, studied in clinical trials
Alternative form with potentially faster absorption
Clinical Notes
- Most effective in populations with elevated muscle catabolism (elderly, sarcopenic, critically ill).
- Limited evidence for benefit in healthy, trained individuals.
- Generally well-tolerated at 3 g/day; no serious adverse effects reported in short-term studies.
- Long-term safety data beyond 12 weeks are limited.
- May interact with immunosuppressants or medications affecting protein metabolism; use with caution in renal impairment.
Research
HMB supplementation shows no significant effect on endurance performance or VO₂ max in healthy individuals.
HMB supplementation helps reduce muscle loss in older adults aged 65+.
HMB improves muscle mass, strength, and physical performance in patients with sarcopenia.
3 g/day HMB for 6 weeks did not affect strength or body composition in trained men.
3 g/day HMB for 4 weeks showed no significant changes in strength or body composition in collegiate football players.
7-day HMB supplementation (3 g/day) reduced inflammation and improved protein metabolism in COPD patients in ICU.
Discusses D-β-hydroxybutyrate (a ketone body), not HMB; not directly relevant to HMB's muscle-related effects.
Focuses on exogenous ketone supplements and blood glucose; not directly related to HMB.
HMB significantly improves lean mass and physical function in sarcopenic patients.
HMB has a positive effect on fat-free mass in older adults
