MK-677

MK-677 (ibutamoren) is a non-peptide, orally-active ghrelin-receptor agonist. It is the most-cited oral GH secretagogue and is studied for sustained…

Orally-active small-molecule ghrelin-receptor agonist studied for sustained GH/IGF-1 elevation.

MK-677 (ibutamoren) is a non-peptide, orally-active ghrelin-receptor agonist. It is the most-cited oral GH secretagogue and is studied for sustained increases in GH and IGF-1 over 24-hour windows.

Overview

MK-677 is technically a small molecule (not a peptide) that mimics ghrelin at the GHS-R1a receptor. Its oral availability and long duration of action have made it a research staple for sustained GH elevation studies.

Mechanism of action

Non-peptide ghrelin mimetic — selective agonist at GHS-R1a, producing sustained GH and IGF-1 elevation across the dosing interval.

Researched applications

• Sustained GH/IGF-1 elevation research
• Body-composition studies
• Sleep-architecture research

Quick facts

Property	Detail
Class	Non-peptide ghrelin (GHS-R1a) agonist
Route	Oral
Half-life	~24 hours
Typical research dose	10–25 mg/day

Half-life

Reported half-life: ~24 hours.

Other growth hormone support peptides

MK-677 sits in our growth hormone support category. These are the other compounds in the same category, useful when you are deciding which reference page to read next.

• CJC-1295 — A growth hormone–releasing hormone analog studied for endogenous GH support.
• Ipamorelin — Selective ghrelin-receptor agonist studied for clean GH pulses.
• Sermorelin — GHRH (1-29) analog used in long-running clinical and research literature.

MK-677 head-to-head

• Ipamorelin vs Ibutamoren (MK-677): Ipamorelin vs ibutamoren (MK-677) side by side: mechanism, half-life, GH pulse pattern, oral vs injectable, and typical cycle length.

Storage and shelf life

State	Conditions	Shelf life
Lyophilized (Powder)	Refrigerate 2–8°C (36–46°F) or freeze	12–24 months refrigerated; longer frozen
Reconstituted	Refrigerate 2–8°C only; no freezing	21–30 days typically
In Transit	Insulated packaging; ice packs	Minimize time; avoid heat exposure
MK-677 (Oral)	Room temp okay; cool/dry preferred	Per manufacturer; typically 12+ months

Sources

• Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults — PubMed / NCBI (accessed 2026-06-13): https://pubmed.ncbi.nlm.nih.gov/19064627/

Review status

This reference page was last reviewed on 2026-06-13 by the Clarity Wellness editorial team.

Important

All peptide products referenced are intended solely for research, investigational, or licensed professional use. They are not FDA-approved and are not intended to diagnose, treat, cure, or prevent any disease. Consult a licensed medical practitioner before any personal or clinical use.

Frequently asked questions

Is MK-677 a peptide?

Technically no — it is a small-molecule ghrelin mimetic, but it is commonly grouped with peptides because it targets the same GH pathway.

Can MK-677 be taken orally?

Yes. Oral availability is one of its main research distinctions versus injectable secretagogues like Ipamorelin.