MK-677

Mechanism

Small-molecule GHS-R1a agonist that raises GH and IGF-1 orally.

Reported effects

What sources associate with this compound. Reported categories, not outcomes we have graded — each would need its own citation and rung.

• Lean-mass gain
• GH/IGF-1 elevation
• Oral convenience

Figures

Every figure below is replotted by this site from values published in the cited paper's text or tables — the numbers are the study's, the drawing is ours, and the evidence rung on each image is the rung of its source.

Half-life, storage & sport

Elimination half-life

not on file — The only figure published is 6 to 13 hours in plasma, quoted by the authors of a randomised dialysis trial from the sponsor's unpublished investigator's brochure rather than measured in their study. No Merck pharmacokinetic paper stating a half-life could be retrieved. It is in any case the half-life of the molecule, not the roughly 24 hours a single daily oral dose keeps growth hormone and IGF-1 raised.

Storage

Lyophilised: Powder (small molecule, not a peptide): -20C, sealed, protect from moisture. Reconstituted: In DMSO solvent: -80C 6 months, -20C 1 month; avoid freeze-thaw. — source. MedChemExpress technical datasheet, ibutamoren mesylate.

In sport (WADA 2026)

Prohibited, at all times — named S2.2.4 (GHS: ibutamoren (MK-677)). the list

Literature on file 7

• review or editorial
  Therapeutic Peptides in Aesthetic, Metabolic and Endocrine Conditions: Effects, Safety, Clinical Applications, and Future Perspectives. graded on: indexed as "review-article" - secondary literature, not a study — “review-article”
• human observational
  Systematic review of undeclared prohibited substances and pharmacological adulterants in dietary supplements: prevalence, detection, and risks in sport. graded on: a synthesis of human studies — “Systematic review”
• human case series
  Knowing the minimal detectable dose can facilitate the interpretation of a hair test result: II. Case example with ibutamoren (MK-677), a growth hormone secretagogue. graded on: two documented human dosing cases (single 10 mg dose; 60 x 10 mg over 90 days) with hair assay — read from the abstract — “abstract review”
• animal in vivo
  Acute stress suppresses hunger-driven food seeking through PVN activation: Reversal by anxiolytic drug and ghrelin receptor agonist, with anxiolytic-like effects of refeeding. graded on: an animal model — read from the indexed abstract — “mice”

Not graded

3 citations whose study design could not be read from the title. Left ungraded rather than guessed at.

• not graded
  Ibutamoren Mesylate (2006)
• not graded
  Growth Hormone Secretagogues as Potential Therapeutic Agents to Restore Growth Hormone Secretion in Older Subjects to Those Observed in Young Adults.
• not graded
  NCT00474279: Effects of an Oral GH Secretagogue (MK-677) on Body Composition and Functional Ability of Older Adults graded on: NCT00474279 is completed and has posted no results - a registration, not a reported outcome — “NCT00474279”

What is circulated not evidence 3

Claims passed around in community guides and vendor copy, recorded because they circulate — not because they are true. Each is shown with the page it was read from and what this record actually holds. Checked 2026-08-24.

• unverified community data dose ubiquitous agrees with the record

  A 20-30 mg nightly oral dose, taken before bed to align with the nocturnal GH pulse, is circulated as the standard protocol, with 10-15 mg advised as a start.

  recommended to take it before bed to align with the body's natural growth hormone cycle

  On the record Dosing on file is 10-25 mg daily; the 30 mg upper end circulated exceeds the on-file range, and no timing (morning versus night) record exists.

  Source 1 · Source 2

• unverified community data side effect common cannot be checked

  Reduced insulin sensitivity and raised blood sugar are circulated as side effects users should watch.

  MK-677 can also impact blood sugar levels and reduce insulin sensitivity

  On the record The record's benefit rows are lean-mass gain, GH/IGF-1 elevation and oral convenience; check the compound's side-effect table for an insulin-sensitivity row before treating this as uncovered.

  Source 1

• unverified community data side effect ubiquitous nothing on file either way

  Intense hunger in the first weeks that later subsides, lethargy, and lower-limb water retention are circulated as the expected early side effects.

  increased appetite, which arises from its action on the ghrelin receptor

  On the record Hunger is mechanistically consistent with the ghrelin-mimetic record; the 'subsides after 3 weeks' time course is a community observation with no record behind it.

  Source 1

Identity

PubChem CID 6450830 computed 3D conformer

Skeletal formulathe canonical depiction

Drawn by PubChem from CID 6450830, the identifier on this record.

Molecular weight

624.8

Molecular formula

C28H40N4O8S2

CAS number

159752-10-0

PubChem CID

6450830

InChI key

DUGMCDWNXXFHDE-VZYDHVRKSA-N

SMILES

CC(C)(C(=O)N[C@H](COCC1=CC=CC=C1)C(=O)N2CCC3(CC2)CN(C4=CC=CC=C34)S(=O)(=O)C)N.CS(=O)(=O)O

InChI

InChI=1S/C27H36N4O5S.CH4O3S/c1-26(2,28)25(33)29-22(18-36-17-20-9-5-4-6-10-20)24(32)30-15-13-27(14-16-30)19-31(37(3,34)35)23-12-8-7-11-21(23)27;1-5(2,3)4/h4-12,22H,13-19,28H2,1-3H3,(H,29,33);1H3,(H,2,3,4)/t22-;/m1./s1

Classified as

Ghrelin Receptor Agonismmechanism

This is the mechanism behind the compounds usually filed as secretagogues, and it explains why appetite effects appear in the same records as growth hormone effects rather than as an unrelated aside.

Growth Hormone / IGF-1 Axispathway

The lab value people actually track, IGF-1 in ng/mL, sits two steps downstream of where most of these compounds act, so a record's mechanism and its measurable marker are rarely the same thing.

Oralroute

Route sets what a milligram means. An oral figure and an injected figure for the same compound are not comparable amounts, and treating one as the other is one of the commonest ways a record gets misread.

Also called

• MK-677
• MK-677 (Ibutamoren)

Listed prices 116

What 44 shops we track listed for MK-677, read from their own public catalogues on 2026-09-14. We take no commission on these and they are not ranked by any payment — how vendors are scored.

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