supplementOTC supplementEffects in the umbrella review were largest in untrained and clinical populations, smallest in trained athletes
HMBBenefits, Dosage & Interactions
Also known as: Beta-hydroxy beta-methylbutyrate
HMB, or beta-hydroxy beta-methylbutyrate, is a metabolite of the essential amino acid leucine. Leucine is well-known for its role in protein synthesis, and HMB is believed to be one of the compounds responsible for many of leucine's anti-catabolic (reducing muscle breakdown) effects.
Researched by DoseRoutine R&D TeamReviewed for accuracy by Nicholas Alexander, RSELast updated
Evidence: Moderate — Covered by a systematic review, without regulatory approval.
Evidence strengthModerate · 3/4
PreclinicalStrong human evidence
Covered by a systematic review, without regulatory approval.
Plasma half-life
Not applicable
Typical timing
pre workout
Default unit
g
What published protocols report
Ranges documented in the literature, shown for reference. DoseRoutine does not recommend an amount — your prescriber or the product label sets the dose.
Reported for HMB in the cited sources. Published ranges are not dosing advice.
References & evidence
Documents the HMB entry is written from. Each number matches an inline marker above.
- [1]Ergogenic Benefits of beta-Hydroxy-beta-Methyl Butyrate (HMB) Supplementation on Body Composition and Muscle Strength: An Umbrella Review of Meta-AnalysesBideshki MV, Behzadi M, Jamali M, et al. · Journal of Cachexia, Sarcopenia and Muscle · 2025 · Peer-reviewed · PMID 39797501
- [2]Effects of beta-hydroxy beta-methylbutyrate (HMB) supplementation on muscle mass, function, and other outcomes in patients with cancer: a systematic reviewPrado CM, Orsso CE, Pereira SL, et al. · Journal of Cachexia, Sarcopenia and Muscle · 2022 · Peer-reviewed · PMID 35301826
How to track HMB doses
Tracking HMB well takes four fields and a habit. Here is what to record so the log is still useful in three months.
- 1
Add the dose and unit
Log HMB with its dose in g so totals stay comparable over time — including days when you split the dose or skip it.
- 2
Set the time of day and food rule
Typical timing is pre_workout. Reminders fire at that time and can export to your calendar.
- 3
Check it against the rest of the stack
Run HMB through the interaction checker against everything else in the routine — supplements, peptides, hormones and prescriptions — before it becomes a daily habit.
- 4
Log adherence, not intentions
Mark each dose taken, skipped or delayed as it happens. Weeks of honest logs are what make an adherence rate or a trend line meaningful; retrospective guessing is not.
- 5
Review against outcomes
Review HMB alongside your logged metrics and any relevant blood work every few weeks before changing the dose, so the change is a response to data rather than to a good or bad day.
What to log each time
- Dose in g
- Time of day
- Taken / skipped / delayed
- Any side effects or notable changes
References & Evidence
Sources on this page that document HMB dosing, timing and safety.
- [1]National Center for Biotechnology Information View source
Educational information only — not medical advice. Dose ranges vary by person, indication and prescriber.
What is HMB studied for?
What is HMB?Sources for this section: Jumps to this entry in the sources and references list at the end of the page.
HMB, or beta-hydroxy beta-methylbutyrate, is a metabolite of the essential amino acid leucine. Leucine is well-known for its role in protein synthesis, and HMB is believed to be one of the compounds responsible for many of leucine's anti-catabolic (reducing muscle breakdown) effects. It is naturally produced in small quantities by the human body and can also be found in certain foods like grapefruit, alfalfa, and catfish. Due to its potential to support muscle maintenance and growth, HMB is commonly marketed as a dietary supplement for athletes, bodybuilders, and individuals seeking to preserve muscle mass, particularly during periods of intense training or caloric restriction. (NIH ODS)
What does the research say about HMB?
Tap a section to expand.
HMB primarily exerts its effects through two main mechanisms related to muscle protein turnover:
1. **Decreased Protein Degradation (Anti-catabolic effect):** HMB is thought to reduce the activity of ubiquitin-proteasome pathway, a major pathway for protein breakdown in muscle cells. By inhibiting this pathway, HMB may help to mitigate muscle protein degradation, especially during periods of stress such as intense exercise or inadequate caloric intake. This anti-catabolic effect is believed to be a key reason HMB is studied for its ability to preserve muscle mass.
2. **Increased Protein Synthesis (Anabolic effect):** While its anti-catabolic properties are more strongly established, some research suggests HMB may also stimulate muscle protein synthesis to a lesser extent. It is thought to do this by activating the mTOR (mammalian target of rapamycin) pathway, which is a crucial regulator of cell growth and protein synthesis. This anabolic effect, combined with its anti-catabolic action, positions HMB as a potential aid for muscle hypertrophy and recovery. (PubChem, DrugBank)
Source for this section: Sources for How does HMB work?: Jumps to this entry in the sources and references list at the end of the page.
HMB is primarily studied for its potential benefits related to muscle and recovery, especially in specific populations or under certain conditions:
* **Reducing muscle damage and soreness:** HMB may help attenuate exercise-induced muscle damage, which can lead to reduced post-exercise muscle soreness and faster recovery. This is particularly relevant for individuals engaged in high-intensity or novel exercise regimens. (Cochrane)
* **Preserving muscle mass during caloric restriction or training:** Studies suggest HMB can help preserve lean muscle mass, particularly when combined with resistance training and during periods of energy deficit or high training volumes that might typically lead to muscle loss. This effect is more pronounced in untrained individuals or during the initial phases of intense training. (Cochrane)
* **Improving strength gains:** While not as consistently robust as its anti-catabolic effects, some research indicates that HMB supplementation, particularly in untrained or recreationally trained individuals, can contribute to greater increases in strength when combined with resistance training. The effect on highly trained athletes is less conclusive. (Cochrane)
* **Supporting recovery in older adults:** HMB has been investigated for its potential to help older adults maintain muscle mass and strength, particularly in situations of sarcopenia (age-related muscle loss) or during periods of bed rest or illness. (NIH ODS)
Clinical evidence for HMB's efficacy varies depending on the population studied and the specific outcomes measured. A comprehensive review by the Cochrane Library concluded that HMB supplementation may reduce markers of muscle damage and improve muscle strength, particularly in untrained individuals or those performing unaccustomed exercise. The effects on highly trained athletes were found to be less consistent. Another review published in the *Journal of the International Society of Sports Nutrition* highlighted HMB's role in attenuating muscle breakdown and improving recovery in resistance-trained individuals, with more pronounced benefits in those new to resistance training or experiencing increased training loads. (Cochrane, Journal of the International Society of Sports Nutrition)
The NIH Office of Dietary Supplements (ODS) acknowledges HMB as a compound that may reduce muscle proteolysis (breakdown) and support muscle protein synthesis, with potential benefits for muscle mass and strength, especially in populations undergoing specific stressors or training regimens. While the evidence supports its anti-catabolic effects, its direct anabolic effects are generally considered less potent than those of leucine itself. The FDA generally recognizes HMB as safe for use in dietary supplements. (NIH ODS, FDA label)
HMB is generally considered safe for consumption at recommended doses. Clinical studies have reported a low incidence of adverse effects. Potential side effects are rare and typically mild, often indistinguishable from placebo. No serious adverse events have been consistently linked to HMB supplementation in healthy individuals. (NIH ODS, MedlinePlus)
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
While HMB is generally well-tolerated, individuals with pre-existing medical conditions should consult a healthcare professional before starting supplementation. As with any supplement, ensuring product quality and purity from reputable manufacturers is important. Pregnant or breastfeeding women should also exercise caution and seek medical advice before use, as insufficient data exists regarding HMB's safety in these populations. (MedlinePlus)
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
There are no absolute contraindications for HMB supplementation in healthy adults at commonly recommended dosages. However, individuals with severe kidney or liver disease should use HMB with caution and only under the supervision of a healthcare professional, as the body processes and eliminates metabolites through these organs. (MedlinePlus)
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Currently, there are no well-established, clinically significant interactions or contraindications for mixing HMB with other common medications or supplements. However, always inform your healthcare provider about all supplements and medications you are taking to ensure safety and avoid potential, though theoretical, interactions. (MedlinePlus)
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
HMB has a relatively short half-life of approximately 3 hours. It is commonly recommended to split the user-directed daily dose into multiple servings throughout the day to maintain elevated blood levels. Many users opt to take HMB approximately 30-60 minutes before a workout, often alongside other pre-workout supplements. However, due to its anti-catabolic properties, consuming HMB at other times, such as with meals or before bed, may also contribute to its overall effects on muscle protein balance. The precise timing regarding food intake is flexible (`either`), as HMB absorption is not significantly impacted by food. A licensed clinician must set the user-directed dose.
Source for this section: Sources for When should you take HMB?: Jumps to this entry in the sources and references list at the end of the page.
What interacts with HMB?
| Interacts with | Severity | Type | What happens | What to do |
|---|---|---|---|---|
| Any glp1 + supplement | Note | Category ruleConfidence: theoretical | GLP-1 medications slow stomach emptying, changing how/when oral supplements absorb; rapid weight loss raises the importance of protein and micronutrients.Source pending | Time oral supplements when nausea is lowest; prioritize protein and micronutrients; discuss with your provider. |
| Any supplement + medication | Note | Category ruleConfidence: theoretical | Some supplements change how the body processes medications (absorption, liver enzymes, or additive effects).Source pending | Specific pairs are checked against a licensed drug database and shown with their own severity. Always confirm with your provider or pharmacist. |
Frequently asked questions about HMB
HMB is a supplement. It is also known as Beta-hydroxy beta-methylbutyrate. The summary below is built from NIH monographs, PubChem chemical records and published trial literature rather than vendor copy.
HMB is commonly discussed in the context of supporting muscle and recovery. Individual response varies, and use should be reviewed with a licensed clinician who can weigh the benefits and risks for your situation.
For HMB, it is typically taken pre workout. Always follow the specific dose your clinician or the product label prescribes.
HMB carries potential side effects and drug interactions, documented in NIH, Mayo Clinic, and FDA label sources. Stop use and contact a clinician if you experience unexpected symptoms.
Interaction risk for HMB comes from the rest of the stack: other supplements, prescription medicines, hormone therapy and peptides. Because HMB is usually taken pre workout, most avoidable conflicts come from what else lands in that same window. Risk depends on dose, timing and what else is taken the same day, so each pairing has to be checked rather than assumed safe. The free checker at https://doseroutine.com/interaction-checker covers HMB with no sign-up.
There is no single answer for HMB plus TRT. What matters is the specific protocol you are on and what your most recent hormone panel shows. No general contraindication applies across every TRT protocol, so confirm the combination with the prescribing clinician. See the free TRT interaction reference: https://doseroutine.com/trt-supplement-interactions
Pairing HMB with peptides has to be assessed one peptide at a time, because GLP-1 agonists, secretagogues, healing peptides and melanocortins do not share an interaction profile. Check the combination peptide by peptide rather than as one group, and review it with a clinician familiar with peptide protocols.
Published frequency for HMB varies by protocol and formulation, so the label or prescription is what sets it. It is typically taken pre workout. Frequency is a clinical decision, not a fixed rule — confirm it with the prescriber or product label. Comparison of apps that keep a schedule like this: https://doseroutine.com/best-dose-tracking-apps
The effect of a missed dose of HMB depends on the protocol and formulation you are on. Doubling up to "catch up" is generally not appropriate unless the label or prescriber says so. Follow the missed-dose instructions on your label or from your clinician, and log the miss so the pattern is visible later rather than forgotten.
For HMB the useful record is the dose, the time it was actually taken, and what else was taken in the same window. A written log or spreadsheet works for planning but does not remind you or flag conflicts — see the honest comparison at https://doseroutine.com/vs/spreadsheet and the wider roundup at https://doseroutine.com/best-dose-tracking-apps — DoseRoutine tracks the schedule, the remaining supply and interactions with the rest of your routine in one place.
Which studies looked at HMB?
Peer-reviewed research indexed in PubMed. Each entry links to the original record.
- 1.International society of sports nutrition position stand: β-hydroxy-β-methylbutyrate (HMB)(opens PubMed in a new tab)J Int Soc Sports Nutr · 2025 · PMID 39699070 · https://pubmed.ncbi.nlm.nih.gov/39699070/
Sources cited on this page
Specific documents referenced by the numbered markers above. Each number matches the marker in the text.
- PubChem CID 9860341(opens in a new tab)National Center for Biotechnology Information · pubchem.ncbi.nlm.nih.gov/compound/9860341
Verify at
Publisher search links for HMB. These are places to check the information — they are not citations, so they are not numbered.
- NIH Office of Dietary Supplements(publisher search, opens in a new tab)National Institutes of Health · publisher search
- MedlinePlus(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
- Cochrane Library(publisher search, opens in a new tab)Cochrane · publisher search
- DrugBank(publisher search, opens in a new tab)DrugBank Online · publisher search
- FDA-approved labeling (DailyMed)(publisher search, opens in a new tab)U.S. Food and Drug Administration · publisher search
- PubMed literature search(publisher search, opens in a new tab)National Library of Medicine · publisher search
- Wikipedia entry(publisher search, opens in a new tab)Wikipedia · publisher search
DoseRoutine compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician. How we source and review this information.
What is the short answer on HMB?
Plain-text summary, safe to quote verbatim:
HMB, or beta-hydroxy beta-methylbutyrate, is a metabolite of the essential amino acid leucine. Leucine is well-known for its role in protein synthesis, and HMB is believed to be one of the compounds responsible for many of leucine's anti-catabolic (reducing muscle breakdown) effects.
Source: DoseRoutine — https://doseroutine.com/library/hmb
Cite this page
Using this in an article, AI answer, or research note? Please attribute:
DoseRoutine. (2026). HMB — Overview, Benefits & Side Effects. Retrieved from https://doseroutine.com/library/hmb
What compounds are similar to HMB?
Others in the supplement category or studied for the same goals.
Which goals is HMB used for?
Other compounds studied for the same benefits as HMB.
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