Page data last changed: . Registry refreshes and identity assessments are separate from scientific content review.
Not a peptide, but dominates overlapping search demand with peptide GH research.
Also known as: Ibutamoren · MK677
Part of the Growth hormone & IGF peptides cluster
Overview
MK-677 (ibutamoren) is an orally active ghrelin receptor agonist often searched alongside peptide GH secretagogues. It is a small molecule, not a peptide, but belongs to the same research conversation.
Source & context
Biological / chemical source: Synthetic non-peptide (often discussed alongside peptides)
Primary research or clinical context: Research compound (not an approved drug)
Why it appears on a peptide site
Search behavior groups MK-677 with CJC-1295, ipamorelin, and related compounds. We include it for educational disambiguation: it is not a peptide chain.
Structure & chemistry
Molecular identity & reference confidence
Source-supported reference
The selected reference is ibutamoren free base, 528.7 Da. The generated624.8 Da record is the mesylate salt; it is a separate form. This synthetic nonpeptide has no amino-acid sequence model.
- Molecular form
- Ibutamoren free base
- Species
- Not applicable: synthetic nonpeptide small molecule
- Termini (N / C)
- Not applicable: nonpeptide / Not applicable: nonpeptide
Average reference mass · Molecular identity assessment: 2026-10-05
Reference policy updated: 2026-10-05
- PubChem PUG REST selected parent properties · 2026-10-05
- PubChem selected-parent identifiers with depositor attribution · 2026-10-05
- NIH GSRS independently selected parent record · 2026-10-05
- Molecular formula
- C27H36N4O5S
- Average reference mass
- ≈ 528.7
- Backbone
- Ibutamoren free base
- C-terminus
- Not applicable: nonpeptide
- PubChem CID: 178024
- CAS RN: 159634-47-6
- UNII: GJ0EGN38UL
Chemistry values: curated profile, PubChem.
Clinical development snapshot
ClinicalTrials.gov lists 8 registered studies with “MK-677” as an intervention (snapshot 2026-09-06). A registry footprint is not evidence of efficacy or approval.
| NCT | Title | Phase | Status | Updated |
|---|---|---|---|---|
| NCT06948214 | Phase 3 Study of LUM-201 in Children With Growth Hormone Deficiency | Phase 3 | recruiting | 2026-09-04 |
| NCT05364684 | The Impact of Ibutamoren on Nonalcoholic Fatty Liver Disease | Phase 2 | completed | 2026-01-06 |
| NCT01343641 | Growth Hormone Secretagogue MK-0677's Effect on Lean Body Mass in Chronic Kidney Disease Stage 4/5 Subjects | Phase 2 | withdrawn | 2018-05-14 |
| NCT00395291 | Growth Hormone Secretagogue MK-0677 Effect on IGF-1 Levels in ESRD Patients | Not applicable | completed | 2017-02-20 |
| NCT00128115 | Treatment of Sarcopenia in Post-Hip Fracture Patients (0677-032) | Phase 2 | terminated | 2016-01-20 |
| NCT00074529 | Study of MK0677 for the Treatment of Alzheimer's Disease (0677-030)(COMPLETED) | Phase 2 | completed | 2015-07-24 |
MK-677 — reconstitution calculator
Enter how much peptide is in the vial and how much diluent (e.g. bacteriostatic water) is added. The tool returns the resulting solution concentration — and, for any amount you type, the volume it corresponds to. This is educational arithmetic, not a dosing recommendation.
Reference form: Ibutamoren free baseAverage reference mass: 528.7 Da
Enter an amount to see the volume it corresponds to.
Educational concentration mathematics only. This tool does not recommend a dose, amount, or protocol, and nothing here is medical advice. Many peptides are not authorized by Health Canada for human use — see our reconstitution and bacteriostatic-water guides for context.
Change log
Dated observations from the data pipeline (registry flags, trial footprints, identifiers) and editorial reviews of this profile.
- ChemistryPubChem formula updated to C28H40N4O8S2.
FAQ about MK-677
What is MK-677?+
MK-677 (ibutamoren) is an orally active ghrelin receptor agonist often searched alongside peptide GH secretagogues. It is a small molecule, not a peptide, but belongs to the same research conversation.
What Canadian product status is recorded for MK-677?+
Canadian product status for MK-677 has not been verified in this profile. No verified record here does not mean no authorization exists. Status depends on the product, formulation and use; consult Health Canada's product records.
What is the length of the selected reference form for MK-677?+
The selected reference form (Ibutamoren free base) is a peptidomimetic without a conventional peptide chain; an amino-acid length does not apply.
Related peptides
References & further reading
- 1.Murphy et al. (1998). MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism. J Clin Endocrinol Metab
- 2.Cobani et al. (2025). Hepatotoxicity induced by MK-677. BMJ Case Rep
- 3.Kintz et al. (2026). 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. Clin Chim Acta
- 4.Cardaci et al. (2022). LGD-4033 and MK-677 use impacts body composition, circulating biomarkers, and skeletal muscle androgenic hormone and receptor content: A case report. Exp Physiol
- 5.Copinschi et al. (1997). Prolonged oral treatment with MK-677, a novel growth hormone secretagogue, improves sleep quality in man. Neuroendocrinology
- 6.Copinschi et al. (1996). Effects of a 7-day treatment with a novel, orally active, growth hormone (GH) secretagogue, MK-677, on 24-hour GH profiles, insulin-like growth factor I, and adrenocortical function in normal young men. J Clin Endocrinol Metab
- 7.Sevigny et al. (2008). Growth hormone secretagogue MK-677: no clinical effect on AD progression in a randomized trial. Neurology
- 8.Lee et al. (2018). Effect of the Orally Active Growth Hormone Secretagogue MK-677 on Somatic Growth in Rats. Yonsei Med J
- 9.PubChem — compound summary for Ibutamoren / MK-677 (CID 178024)
- 10.Wikipedia — Ibutamoren (MK-677)