STUDresearch · Non-peptide
HMB
Also known as
beta-hydroxy-beta-methylbutyrate · β-hydroxy β-methylbutyrate · Ca-HMB · HMB-FA · BetaTOR-class free acid · hydroxymethylbutyrate · leucine metabolite HMB
Community talk. May contain inaccuracies. Not medical advice. Not a protocol. Not for human or animal use.
Non-peptide
Some talk
Systemic
Oral Ca-HMB capsules or powder
Performance staples (biohacking overlap)
Systemic oral leucine metabolite — muscle-spare talk on cuts and GLP threads, not a myostatin antibody.
What people say
HMB is an oral leucine metabolite (Ca-HMB or free acid). 2025–26 talk is muscle-spare on a cut or a GLP. It is not bimagrumab or trevogrumab.
Doses people talk about
GLP muscle-spare screenshots still sit on creatine, protein and lifting.
How it may feel
Usually no pump. Cut/GLP logs judge leftover strength over weeks. No antibody-style fullness diary.
Paper / ISSN daily amount3 g/day
Often split 1 g × 3 for Ca-HMB in the studies people paste. Not an antibody milligram.
ISSN body-weight figure~38 mg/kg/day
The same 3 g story for many adults in the position stand, not a second protocol.
HMB-FA same milligrams, faster peak3 g/day
HMB-FA same milligrams, faster peak than Ca-HMB in the PK comparison. Not a myostatin conversion.
Half-life & effect duration
- Half-life in the body
- Calcium HMBAbout 2.5 hours
- HMB free acidAbout 3 hours
- Felt duration people report
- Acute feelUsually no noticeable hit
- During a cutStrength retention judged over weeks, often alongside creatine and protein
Cycles people discuss
Daily while the cut, GLP, or rehab block is on — not an antibody infusion calendar.
Timing
Plasma t½ about 2.5 h (Ca-HMB) and 3 h (HMB-FA). That is not a myostatin-antibody week.
Around the dose
Clock: Split with meals for Ca-HMB logs; HMB-FA peri-workout lore is marketing plus faster peak, not a hypertrophy law.
Stacks
Screenshots pair it with creatine; GLP trays add protein and lifting. Compared with bimagrumab/trevogrumab, not stacked as antibodies.
Access talk
Gym-supplement tub, not a gray mAb. Ca-HMB powder is cheap OTC; HMB-FA gelcaps cost more.
Labs people mention
DEXA / lean-mass snapshots are what GLP-cut threads want; HMB does not have a COURAGE antibody table.
Watch for
Not a myostatin antibody. Oral 3 g is not bimagrumab or trevogrumab.
Tap a line for the full notes and source context.
Timing context & sources
Half-life in the body
About 2.5 hours for calcium HMB and about 3 hours for HMB free acid in the ISSN-cited plasma comparison.
HMB-FA peaked faster and higher than equivalent Ca-HMB; that is absorption, not a 19-day antibody clock.
Small oral PK comparison, not GLP-1 coadministration PK and not myostatin-antibody half-life.
- ISSN position stand — beta-hydroxy-beta-methylbutyrate (JISSN / PMC3568064) (opens in a new tab)3 g/day or ~38 mg/kg; Ca-HMB vs HMB-FA PK: FA peak ~30 min vs Ca ~120 min; plasma t½ ~3 h (FA) and ~2.5 h (Ca).Position stand synthesizing older PK and training papers; not a 2026 GLP-1 combination RCT and not a myostatin-antibody study.
Felt duration people report
Usually no acute feel. Cut/GLP logs judge leftover strength over weeks, confounded by creatine and protein.
There is no antibody-style fullness diary.
n=1 cut logs are not a PK or mAb comparison.
- ISSN position stand — beta-hydroxy-beta-methylbutyrate (JISSN / PMC3568064) (opens in a new tab)3 g/day or ~38 mg/kg; Ca-HMB vs HMB-FA PK: FA peak ~30 min vs Ca ~120 min; plasma t½ ~3 h (FA) and ~2.5 h (Ca).Position stand synthesizing older PK and training papers; not a 2026 GLP-1 combination RCT and not a myostatin-antibody study.
What people say
- Untrained or deficit: The diaries that sound good usually start from a cut, a layoff, or a newbie block. forum
- Trained, fed lifters: “Did nothing next to creatine” is a repeated log. forum
- GLP muscle-spare talk: 2025–26 narrative reviews name 3 g/day HMB as a plausible add-on during GLP-1 weight loss and say the GLP-specific trial is still missing. trialforum
- Not DEXA-screenshot mAb territory. COURAGE/bimagrumab tables are a different molecule class. forum
- ISSN position stand: ~3 g/day (or ~38 mg/kg) discussed for hypertrophy/strength/power when training is actually programmed — not a sit-on-the-couch pill. trial
- Older-adult / sarcopenia meta-analyses: Modest lean-mass and function signals, bigger when exercise is in the arm. trial
- Creatine + HMB marketing claims synergy; factorial evidence is mixed and often creatine-shaped. trial
Doses people talk about
- 1 g undershoot: Single-scoop “HMB blends” in pre-workouts often miss 3 g. forum
- Do not convert 3 g oral HMB into bimagrumab milligrams. forum
- Framing: Studied oral milligrams. Not an antibody milligram and not a protocol. forum
- Default paper band: 3 g/day HMB, often split 1 g × 3 with meals for Ca-HMB. trial
- HMB-FA timing talk: Same 3 g, faster plasma peak (~30 min vs ~2 h for Ca-HMB in the comparison people paste). trial
- ISSN body-weight figure: About 38 mg/kg/day in the position stand — the 3 g story for many adults, not a second ladder. trial
How it may feel
- Days 1–7: Usually no pump, no buzz. GI if they slam 3 g once. forum
- Weeks 2–8 on a cut or GLP: The hope is “scale down, lift still there.” Confounded by protein and training. forum
- If already on creatine and eating: Many logs stay flat. forum
- Stop: No receptor-withdrawal lore; people just stop buying the tub. forum
- vs antibody feel: There is no fullness diary like FLGR or bimagrumab talk. Powder is boring. forum
Around the dose
- Clock: Split with meals for Ca-HMB logs; HMB-FA peri-workout lore is marketing plus faster peak, not a hypertrophy law. forum
- Training: The threads that like it are the ones still lifting on a deficit or a GLP. forum
- Protein: People who skip protein and expect HMB to replace food get mocked in the same comments. forum
- After: No change after a few weeks next to creatine and they drop the tub first, not the creatine. forum
Cycles people discuss
- Daily while the cut / GLP / rehab block is on. Not a 4-week SARM. forum
- GLP users in those threads keep it next to creatine for the whole titration. Inferential habit. forum
- Not an antibody infusion calendar. forum
- Older-adult trials ran weeks to months. trial
Timing
- Daily 3 g is a studied intake, not because the half-life is 19 days. forum
- Do not paste myostatin-antibody weeks onto HMB. forum
- Plasma half-life about 2.5 hours (Ca-HMB) and about 3 hours (HMB-FA) in the ISSN-cited comparison. trial
- HMB-FA peaked faster and higher than an equivalent Ca-HMB dose in that PK work; urinary loss was similar. trial
- 3 g Ca-HMB peaked sooner than 1 g in Vukovich-style dose work — more plasma, more urine. trial
More on what it is
- Why people talk about it in 2025–26: Semaglutide/tirzepatide cut threads add “creatine + HMB + protein + lift” as the lean-mass cope. That stack is inferential, not a dedicated GLP+HMB RCT. forum
- Not a myostatin antibody. Bimagrumab and trevogrumab are clinic mAbs. HMB is a 3 g oral powder. forum
- Creatine pairing is the other half of almost every screenshot. forum
- What it is: Beta-hydroxy-beta-methylbutyrate, a leucine metabolite. Gym tubs are usually calcium HMB (Ca-HMB); some labels are free-acid gelcaps (HMB-FA). trial
- How discussion frames mechanism: Less ubiquitin-proteasome breakdown, some mTOR talk. Anti-catabolic more than “new muscle from nowhere.” trial
- Evidence honesty: Stronger in older, untrained, or calorie-deficit contexts; trained, well-fed lifters often see little. ISSN still treats 3 g/day as the studied amount. trial
Stacks
- + Creatine monohydrate is the default screenshot (3 g HMB + 3–5 g creatine in those posts). forum
- + Protein / lifting on semaglutide or tirzepatide is the 2025–26 GLP muscle-spare tray. Inferential. forum
- Compared with Bimagrumab / Trevogrumab, not stacked as antibodies. forum
- Not a Wolverine peptide stack. forum
Access talk
- Gym-supplement tub, not a gray mAb. Ca-HMB powder is cheap OTC; HMB-FA gelcaps cost more. forum
- Not bimagrumab, not trevogrumab, not FLGR. If a peptide shop lists “HMB,” that is still the leucine metabolite — or it is a mislabel. forum
- Pre-workout 500 mg line items are why people buy a separate 3 g tub. forum
- No reconstitution culture. forum
Labs people mention
- DEXA / lean-mass snapshots are what GLP-cut threads want; HMB does not have a COURAGE antibody table. forum
- No standard hormone panel for HMB the way TRT logs have one. forum
- On a GLP: people watch weight vs strength, not an HMB blood level. forum
- CK / recovery markers show up in older training papers more than in consumer Quest carts. trial
Storage notes
- Powder / caps, not BAC water. forum
- Dry tub; free-acid gelcaps follow ordinary cool/dark bottle talk. forum
Watch for
- Not a myostatin antibody. Oral 3 g is not bimagrumab or trevogrumab. forum
- GI if 3 g is taken as one hit, especially Ca-HMB powder. forum
- Trained-lifter nonresponse next to creatine is common enough to be the skeptic line. forum
- Underdosed blends create false-negative logs. forum
- Not a SARM and not a substitute for protein + lifting. forum
- GLP-specific RCT still missing — narrative reviews say “plausible,” not proven on semaglutide. trial
Evidence mix
Mostly community / anecdote tags
Full: every bullet (trial + community). Use Scan for a faster bro-science read.