HMB
Amino Acid ·Exploratory record · not publication-reviewed ·Updated July 13, 2026
Metabolite of leucine that reduces muscle protein breakdown.
Exploratory record, not a reviewed medical publication.
See the editorial and medical-review policies for the publication gate.
This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.
What the research says.
A quick, data-only summary. The full evidence, dosing, and sources are below.
HMB is an amino acid most often used for muscle preservation, recovery, strength. NutriStack rates the overall evidence as moderate. A typical adult dose is 3 g daily (split into 3 doses), commonly taken as calcium hmb or free acid hmb. This profile indexes 21 sources.
The bottom line
Evidence rating moderate. Most-documented uses: muscle preservation, recovery, strength. 21 sources indexed (2004–2025), with 0 interaction records on file.
How it works, mechanistically.
Core mechanism
Inhibits the ubiquitin-proteasome pathway responsible for muscle protein degradation. Also stimulates mTOR pathway and enhances muscle protein synthesis.18,19
Dosing & protocol.
Split doses with meals; free acid form 30 min before exercise1,2
What it actually costs.
Real-world pricing across three quality tiers. Assumes Calcium HMB.
Assumes 3 g/day split dosing. Vendor basis: BulkSupplements powder, NOW Sports/iHerb, Vitacost, and Amazon marketplace; free-acid HMB products price premium. Updated 2026-05-28.
The same dose, as food.
How much you'd eat to match a supplemental dose.
A practical food equivalent for HMB does not exist; HMB is also made in small amounts from leucine.
Full safety detail.
Side effects
- Well tolerated
- Mild GI at high doses
Contraindications
- Generally very safe
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Meta-analyses & systematic reviews
15- 1The effects of β-hydroxy-β-methylbutyrate supplementation in patients with sarcopenia: A systematic review and meta-analysisPMIDGu WT, Zhang LW, Wu FH, Wang S · Maturitas · 2025
In 5 RCTs, HMB supplementation showed beneficial effect on skeletal muscle mass index (SMD 0.32, P=0.048) and handgrip strength (SMD 0.65, P=0.034), but no evidence of benefit on physical performance measured by gait speed.
- 2Effects of oral supplementation of beta-hydroxy-beta-methylbutyrate on muscle mass and strength in individuals over the age of 50: a meta-analysisSource linkedPMIDLi N, Chen S, He Y et al. · Frontiers in Nutrition · 2025
- 3Effects of β-hydroxy-β-methylbutyrate (HMB) supplementation on lipid profile in adults: a GRADE-assessed systematic review and meta-analysis of randomized controlled trialsPMIDSadeghi B, Bahari H, Jozi H et al. · Frontiers in nutrition · 2024
Sadeghi B, Bahari H, Jozi H et al.. Effects of β-hydroxy-β-methylbutyrate (HMB) supplementation on lipid profile in adults: a GRADE-assessed systematic review and meta-analysis of randomized controlled trials. Frontiers in nutrition. 2024
- 4The effects of β-hydroxy-β-methylbutyrate or HMB-rich nutritional supplements on sarcopenia patients: a systematic review and meta-analysisPMIDSu H, Zhou H, Gong Y et al. · Frontiers in medicine · 2024
Su H, Zhou H, Gong Y et al.. The effects of β-hydroxy-β-methylbutyrate or HMB-rich nutritional supplements on sarcopenia patients: a systematic review and meta-analysis. Frontiers in medicine. 2024
- 5Effects of exercise with or without β-hydroxy-β-methylbutyrate supplementation on muscle mass, muscle strength, and physical performance in patients with sarcopenia: a systematic review and meta-analysisPMIDFeng Y, Chen P, Li T et al. · Frontiers in nutrition · 2024
Feng Y, Chen P, Li T et al.. Effects of exercise with or without β-hydroxy-β-methylbutyrate supplementation on muscle mass, muscle strength, and physical performance in patients with sarcopenia: a systematic review and meta-analysis. Frontiers in nutrition. 2024
- 6Effect of β-hydroxy-β-methylbutyrate (HMB) on the Muscle Strength in the Elderly Population: A Meta-AnalysisPMIDLin Z, Zhao A, He J · Frontiers in Nutrition · 2022
In 9 RCTs with 896 subjects, HMB supplementation had a statistically significant overall impact on muscle strength-related indicators (SMD 0.41, 95% CI 0.28-0.54, p<0.00001) in the elderly population.
- 7Supplementation with the Leucine Metabolite beta-hydroxy-beta-methylbutyrate (HMB) does not Improve Resistance Exercise-Induced Changes in Body Composition or Strength in Young Subjects: A Systematic Review and Meta-AnalysisSource linkedPMIDJakubowski JS, Nunes EA, Teixeira FJ et al. · Nutrients · 2020
- 8Beta-Hydroxy-beta-methylbutyrate and its impact on skeletal muscle mass and physical function in clinical practice: a systematic review and meta-analysisPMIDBear DE et al. · American Journal of Clinical Nutrition · 2019
15 RCTs with 2,137 patients showed some evidence supporting HMB for increasing skeletal muscle mass and strong evidence for improving muscle strength.
- 9The Effects of Beta-Hydroxy-Beta-Methylbutyrate Supplementation on Recovery Following Exercise-Induced Muscle Damage: A Systematic Review and Meta-AnalysisPMIDRahimi MH, Mohammadi H, Eshaghi H et al. · Journal of the American College of Nutrition · 2018
Rahimi MH, Mohammadi H, Eshaghi H et al.. The Effects of Beta-Hydroxy-Beta-Methylbutyrate Supplementation on Recovery Following Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis. Journal of the American College of Nutrition. 2018
- 10Effect of HMB supplementation on body composition, fitness, hormonal and inflammatory profile in trained and competitive athletes: a meta-analysisSource linkedPMIDSanchez-Martinez J, Santos-Lozano A, Garcia-Hermoso A et al. · J Sci Med Sport · 2018
- 11β-hydroxy-β-methylbutyrate free acid supplementation may improve recovery and muscle adaptations after resistance training: a systematic reviewPMIDSilva VR, Belozo FL, Micheletti TO et al. · Nutrition research (New York, N.Y.) · 2017
Silva VR, Belozo FL, Micheletti TO et al.. β-hydroxy-β-methylbutyrate free acid supplementation may improve recovery and muscle adaptations after resistance training: a systematic review. Nutrition research (New York, N.Y.). 2017
- 12Effect of beta-hydroxy-beta-methylbutyrate supplementation on muscle loss in older adults: a systematic review and meta-analysisPMIDWu H et al. · Archives of Gerontology and Geriatrics · 2015
Seven RCTs with 287 older adults showed HMB supplementation contributed to greater muscle mass preservation compared to controls.
- 13Effects of beta-hydroxy-beta-methylbutyrate on muscle strength loss during immobilization: a meta-analysisSource linkedPMIDWu H, Xia Y, Jiang J et al. · Clin Nutr · 2015
- 14Beta-hydroxy-beta-methylbutyrate supplementation in health and disease: a systematic review of randomized trialsPMIDMolfino A, Gioia G, Rossi Fanelli F et al. · Amino acids · 2013
Molfino A, Gioia G, Rossi Fanelli F et al.. Beta-hydroxy-beta-methylbutyrate supplementation in health and disease: a systematic review of randomized trials. Amino acids. 2013
- 15Effects of beta-hydroxy-beta-methylbutyrate supplementation during resistance training on strength, body composition, and muscle damage in trained and untrained young men: a meta-analysisPMIDRowlands DS et al. · Journal of Strength and Conditioning Research · 2009
HMB is effective in preventing exercise-related muscle damage in both trained and untrained individuals during resistance training.
Randomized controlled trials
3- 16Effects of preoperative beta-hydroxy-beta-methylbutyrate, arginine, and glutamine supplementation on cardiac surgery: A randomized controlled trialPMIDOgawa M, Satomi-Kobayashi S, Yoshida N et al. · Clinical nutrition (Edinburgh, Scotland) · 2025
Ogawa M, Satomi-Kobayashi S, Yoshida N et al.. Effects of preoperative beta-hydroxy-beta-methylbutyrate, arginine, and glutamine supplementation on cardiac surgery: A randomized controlled trial. Clinical nutrition (Edinburgh, Scotland). 2025
- 17HMB free acid gel supplementation during resistance trainingSource linkedPMIDWilson JM, Lowery RP, Joy JM et al. · Br J Nutr · 2014
- 18Mechanism of the attenuation of proteolysis-inducing factor stimulated protein degradation in muscle by beta-hydroxy-beta-methylbutyratePMIDSmith HJ et al. · Cancer Research · 2004
At 50 micromol/L concentration, HMB completely attenuated PIF-induced protein degradation and induction of the ubiquitin-proteasome proteolytic pathway.
Reviews & position papers
2- 19Mechanism of Action and the Effect of Beta-Hydroxy-Beta-Methylbutyrate (HMB) Supplementation on Different Types of Physical Performance - A Systematic ReviewPMIDTeixeira FJ et al. · Journal of Strength and Conditioning Research · 2019
HMB inhibits ubiquitin-proteasome protein degradation, decreases cell apoptosis, stimulates mTOR-mediated protein synthesis, and enhances GH/IGF-1 axis and muscle stem cell proliferation.
- 20International Society of Sports Nutrition position stand: beta-hydroxy-beta-methylbutyrate (HMB)Source linkedPMIDWilson JM, Fitschen PJ, Campbell B et al. · J Int Soc Sports Nutr · 2013
Common questions.
Quick answers about HMB, drawn from the data on this page.
What is HMB?
Metabolite of leucine that reduces muscle protein breakdown.
What is HMB used for?
Commonly cited benefits of HMB include: Muscle preservation; Recovery; Strength. NutriStack rates the overall evidence as moderate.
What is a typical dose of HMB?
A typical adult dose of HMB is 3 g daily (split into 3 doses). The commonly recommended form is Calcium HMB or free acid HMB. These are general ranges, not personalized advice; confirm the right dose with a clinician.
What are the side effects of HMB?
Reported side effects include well tolerated, mild gi at high doses. This is educational information; check with a healthcare professional before use.
How strong is the evidence for HMB?
NutriStack rates this as Moderate, meaning several aligned RCTs or one large RCT plus supporting reviews. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.
Use this with your stack
HMB in NutriStack.
Add it to your stack, see how it interacts with everything else you take, and get a Stack Score that updates the moment it does.