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STUDresearch · Non-peptide

Bimagrumab

Also known as

BYM338 · bima

Community talk. May be wrong. Not medical advice. Not a protocol. Not for human or animal use.

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Non-peptide Some talk Systemic IV / SubQ (trials) Growth factors / muscle

Systemic antibody against activin receptor pathway.

What people say Bimagrumab is an investigational monoclonal antibody against activin type II receptors, studied for body-composition and metabolic outcomes. It is a biologic, not a peptide vial product. Doses people talk about
Registered Phase 2 arms10 or 30 mg/kg IV

NCT05616013 used protocol-defined visits rather than a simple continuous monthly calendar.

Phase 1 subcutaneous bolus arms52.5, 150 or 300 mg SC weekly

Three fixed bolus arms, 12 weekly doses in a controlled Phase 1 study of adults aged at least 70; separate from the IV arms and SC-infusion formulations.

Route, formulation and schedule differ across studies. Milligram-per-kilogram IV regimens cannot be converted into a gray-market vial routine.

Half-life & effect duration

Half-life in the body
  • IV · high concentrationsAbout 19 days
  • IV · fastest clearanceAbout 5 days
Felt duration people report
  • Felt durationNo consistent firsthand window reported
  • Observed during studiesMuscle spasms, rash or digestive effects; body changes assessed over weeks
Timing context & sources
How it may feel Controlled studies report adverse events such as muscle spasms, rash and diarrhea, while community threads mostly discuss access, cost and trial expectations. The inspected threads did not supply a verified first-person use diary.
Cycles people discuss Older notes describe unverified weeks-on/off discussion driven by cost and caution. Checked threads contained no verified self-use calendar; controlled studies use protocol-defined schedules. Timing Human study schedules use IV infusions weeks apart, often in monthly or four-week patterns. These are study-specific infusion visits, not a daily SubQ peptide-stack schedule. Stacks Conceptually vs myostatin drugs: Compared with other myostatin/activin axis agents. Watch for Trial adverse events / monitoring: Earlier trial discussion flags GI and muscle-enzyme changes and lab monitoring. In the checked single-dose IV study, commonly reported events included muscle spasms, rash and diarrhea; that study does not establish the safety of unverified products.
Related
ACE-031Apitegromab

Tap a line to jump into the full notes. Research only — may be wrong.

Timing context & sources

Half-life in the body

Sponsor documentation reports roughly 5–19 days after human IV administration, depending on concentration.

The estimate spans maximal clearance to the high-concentration linear region. It summarizes prior human development data, not one trial cohort or one universal terminal value.

Exact estimation sample and derivation are not supplied in the cited protocol passage. Rooks's single-dose study could not derive half-life by NCA. Not SC kinetics, felt duration or a dosing instruction.

  • Bimagrumab sponsor protocol — JAMA Supplement 2, human PK (opens in a new tab)Supplement 2, zoi201022supp2_prod_1614013899.27858.pdf; CBYM338X2211 amended protocol v05 clean; section 1.3.2, printed pages 36–37. Human single/repeat IV concentration-dependent half-life estimates.Sponsor synthesis of prior human IV development data. Exact estimation cohort and derivation are not supplied here; not a direct NCA estimate from the associated trial, SC kinetics or felt duration. The separate ClinicalTrials.gov protocol copy redacts this passage.
  • Rooks et al. — Safety and pharmacokinetics of bimagrumab in older and obese adults (opens in a new tab)Full text Methods, Results, pharmacokinetics and adverse-events sections for single 3 or 30 mg/kg IV dosing; 12-week safety follow-up in obese adults and 20 weeks in older adults.Small single-dose studies; nonlinear PK prevented a conventional noncompartmental half-life estimate and body-composition endpoints are not subjective duration.

Felt duration people report

The reviewed evidence does not establish a dependable felt-effect window after a dose.

Studies measured adverse events and body-composition endpoints over weeks; inspected community threads contained expectations rather than verified use diaries.

Endpoint timing is not a first-person duration diary, and the community evidence set was small and access-focused.

Other context in this card

What people say 5

  • Body-comp talk: Bimagrumab is discussed for recomp, strength continuity, or soft-tissue recovery depending on class. forum
  • Training confound: PRs and scale changes almost always co-travel with diet phase and programming. anecdote
  • Suppression / lipid chatter: Hormonal agents pull bloodwork and PCT conversations even when marketed “mild.” forum
  • Lean mass: Trials reported increases in lean mass. trial
  • Metabolic interest: Obesity/insulin-sensitivity exploration in some programs. trial

Doses people talk about 4

  • Research-chem listings: treat unlabeled “bimagrumab” vials as high mislabel risk. forum
  • Not a daily SC “peptide stack” dose: monthly/q4w-class IV monoclonal schedules dominate literature. trial
  • Trial-style bands: human studies commonly used ~10–30 mg/kg IV every several weeks (exact arm depends on study) for muscle/obesity research contexts. trial
  • Framing: Bimagrumab (BYM338) is a monoclonal antibody against ActRII — clinic/trial dosing, not a peptide vial culture. trial

How it may feel 5

  • First-person evidence: The inspected community threads discussed availability, cost, IV logistics and trial expectations but contained no verified user account of taking bimagrumab. forum
  • Days 2–7: Side-effect window for many agents; benefits, if any, are easy to mis-attribute. forum
  • Weeks 1–2: First honest checkpoint in self-logs. forum
  • Observed study effects: In a single-dose IV study, commonly reported events included muscle spasms, rash, diarrhea and upper-respiratory infection; oral and generic injection-site language does not apply to that study. trial
  • Months: Antibody PK and endpoint windows are longer than daily peptides. trial

Cycles people discuss 4

  • Unverified self-cycle discussion: Older notes describe weeks-on / weeks-off, with cost and caution offered as reasons rather than hard science. The checked threads contained no verified self-use calendar; controlled studies use protocol-defined schedules. forumtrial
  • No magic cycle: There is rarely one universal “correct” on/off calendar across forums. forum
  • Dosing intervals: Weeks between infusions in programs. trial
  • Reassess: Stop and reassess if adverse effects appear; this is not medical care. forum

Timing 3

  • Timing practicalities: People time doses around side effects, training, and sleep more than perfect PK. forum
  • Human PK: Sponsor documentation reports a concentration-dependent half-life of about 19 days at high concentrations and about 5 days at maximum clearance after human IV administration. These program estimates are not a universal terminal half-life or a subjective-effect window; the Rooks single-dose study could not derive half-life by noncompartmental analysis. trial
  • Published PK: Where human PK exists it should override forum half-life memes for Bimagrumab. trial

More on what it is 5

  • Research posture: Educational summary of public discussion and literature themes only. forum
  • How people talk about it: Forum volume is a popularity signal for Bimagrumab, not proof it works for you. forum
  • What it is: Monoclonal antibody vs activin type II receptors explored for muscle mass and metabolic outcomes. trial
  • Not a gray-market vial peptide: Biologic antibody — clinic/trial context, not typical research-chem pen culture. trial
  • Research only: Not approved advice for self-experimentation; legality and access vary by place. forum

Stacks 2

  • Conceptually vs myostatin drugs: Compared with other myostatin/activin axis agents. forum
  • Less is clearer: Solo runs make personal n=1 easier to interpret than five-compound blasts. forum

Storage notes 2

  • No mix instructions here: STUDresearch does not list reconstitution, diluent volumes, or syringe unit charts. People reconstitute many different ways and vial labels differ — that content creates more confusion than clarity. forum
  • Storage (general talk only): Unopened research products are usually kept cool, dry, and away from light per the seller label. Anything after first use is product-specific — follow the label, not a universal forum SOP. forum

Watch for 6

  • Access: Essentially unavailable as consumer research chem. forum
  • Injection site (if injected): Redness, itch, lumps, bruise — technique and product quality matter. forum
  • Unknowns: Long-term safety for gray-market preparations is often poorly characterized. forum
  • Stack noise: Sides logged on multi-agent stacks cannot be blamed cleanly on one compound. forum
  • Seek care red flags: Severe allergic reaction, chest pain, neuro changes, or uncontrolled BP/glucose need real medical care — not forum advice. forum
  • Trial adverse events / monitoring: Earlier trial discussion flags GI and muscle-enzyme changes and lab monitoring. In the checked single-dose IV study, commonly reported events included muscle spasms, rash and diarrhea; that study does not establish the safety of unverified products. trial

Updated: 2026-08-12

Evidence mix Mostly community / anecdote tags Full: every bullet (trial + community). Use Scan for a faster bro-science read.
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