WhatPeptide

MK-677

An oral non-peptide ghrelin receptor agonist often discussed with GH peptides due to GH/IGF-1 stimulating effects. Placed on FDA Category 2 list (September 29, 2023) as 'Ibutamoren mesylate.'

Moderate evidence FDA Category 2 GH Secretagogue

Written by WhatPeptide Editorial Team · Last updated 2026-03-17

FDA Category 2 — compounding availability may be limited.
Non-peptide small molecule (ghrelin receptor agonist) commonly discussed alongside peptides.

Half-life

Elimination half-life ~4–6 hours; pharmacodynamic GH-elevation duration ~24 hours

Dosage range

10-25 mg oral daily (published research context)

Administration

Oral

Research level

Moderate

How MK-677 works

MK-677 is an orally active GHSR agonist that increases endogenous GH and IGF-1 secretion. It also increases appetite and may affect glucose handling with chronic use. While often grouped with peptides in practice, it is pharmacologically a small molecule.

Also known as: Ibutamoren, LUM-201 analog class

Research relevance

GH Boost
Strong research relevance 80
Muscle Growth
Moderate relevance 70
Sleep & Relaxation
Moderate relevance 65
Recovery & Healing
Moderate relevance 55
Anti-Aging & Longevity
Moderate relevance 55
Fat Loss
Some relevance 35
Cognition & Focus
Some relevance 25
Hair & Skin
Some relevance 20
Sexual Health
Some relevance 20
Injury Rehab
Some relevance 20

Side effects & safety

Increased appetite Water retention Lethargy Insulin resistance concerns

Contraindications

Pregnancy
Diabetes or prediabetes without supervision
Cancer history

Consult a healthcare provider before use if any of these apply to you.

Key studies

FAQ

What is MK-677? +
An oral non-peptide ghrelin receptor agonist often discussed with GH peptides due to GH/IGF-1 stimulating effects. Placed on FDA Category 2 list (September 29, 2023) as 'Ibutamoren mesylate.' Its mechanism of action is supported by moderate clinical and preclinical evidence.
What is MK-677 researched for? +
MK-677 has the strongest research relevance for GH Boost, Muscle Growth, Sleep & Relaxation. Evidence is supported by moderate clinical and preclinical evidence.
What are the side effects of MK-677? +
Reported side effects include Increased appetite, Water retention, Lethargy, Insulin resistance concerns. Key contraindications: Pregnancy; Diabetes or prediabetes without supervision; Cancer history.
Is MK-677 FDA approved? +
MK-677 is classified as FDA Category 2, meaning compounding availability may be limited.
How is MK-677 administered? +
MK-677 is typically administered via oral route. Researched dosage range: 10-25 mg oral daily (published research context). Half-life: Elimination half-life ~4–6 hours; pharmacodynamic GH-elevation duration ~24 hours.

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