The Study
The Influence of Acute Beta-Hydroxy Beta-Methylbutyrate (HMB) Ingestion on the Human Skeletal Muscle Transcriptome
This study looked at which genes turned on or off in guys' muscles after they took a supplement called HMB. It didn't compare them to people who didn't take it, so we can't say HMB caused the changes — maybe it was just the time of day or being hungry.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Scientists gave 14 young men a pill of HMB — a substance made from protein — and checked their muscle genes to see what changed.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 544 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1These gene changes look like the body is preparing to build muscle, but the study didn't measure actual muscle growth — just molecular signals.
- 2After taking HMB, 468 genes turned up and 326 turned down — including genes that help bring amino acids into muscle and build proteins, while genes that control daily body rhythms turned down.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Nutrients
Year
2026
Authors
D. Wilkinson, Iain J Gallagher, H. Crossland, Suzette L. Pereira, R. Rueda, B. Phillips, Kenneth Smith, C. Deane, P. Atherton
Related Content
Claims (6)
Taking HMB supplements does not significantly increase muscle growth in people who already eat enough protein, but might slightly affect muscle growth when calorie intake is very low or training intensity is extremely high.
Taking a 3.42-gram dose of HMB orally changes the activity of specific genes in skeletal muscle of healthy young men, increasing those related to nutrient transport and cellular signaling while decreasing those involved in circadian regulation, indicating a shift in molecular activity that may support muscle growth and metabolic adjustment.
Taking HMB shortly before or after exercise is linked to changes in the activity of certain genes in muscle tissue that help regulate the body's daily biological rhythms.
Taking HMB shortly before exercise is linked to higher levels of two specific proteins in muscle tissue that help bring in amino acids and trigger muscle growth pathways.
Taking HMB shortly before or after exercise is linked to changes in the activity of certain genes in muscle tissue that are involved in building proteins and reducing protein breakdown.
Taking HMB shortly before exercise is linked to increased activity of certain inflammation-related genes in muscle tissue, even though the breakdown of muscle proteins decreases at the same time.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.