What is the dosing range for MK-677 (Ibutamoren)?

MK-677 (Ibutamoren) is typically dosed at 10mg (low), 25mg (moderate), or 50mg (high) mg, administered once daily oral. These ranges are aggregated from preclinical research and community protocols — not medical dosing guidance.

What are the reported side effects of MK-677 (Ibutamoren)?

Reported side effects of MK-677 (Ibutamoren) include: Water retention, Increased appetite, Elevated fasting glucose (long-term), Fatigue (initial, transient), Carpal tunnel syndrome (high doses), Elevated prolactin, Lethargy / morning grogginess.

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MK-677 (Ibutamoren)

Also known as: Ibutamoren, Nutrobal, MK677, L-163,191

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MK-677 is a research compound not approved for human use. For informational and research purposes only.

📚 Content aggregated from:2 peer-reviewed sources·r/Peptides community·PubMed / NCBI

Overview

Oral non-peptide growth hormone secretagogue that mimics ghrelin to stimulate GH and IGF-1 release without injection. Long half-life (~24 hours) enables once-daily oral dosing. Widely researched for body composition, sleep quality, and IGF-1 elevation.

Research Summary

MK-677 binds the ghrelin receptor (GHS-R1a) to stimulate pulsatile GH release and increase circulating IGF-1. Unlike peptide GHRPs it survives oral administration. Clinical trials demonstrate significant increases in GH pulsatility and IGF-1 without suppression of the endogenous GH axis, though long-term use raises glucose metabolism concerns.

Dosing Range

low

10mg

moderate

25mg

high

50mg

Units: mg · Frequency: once daily oral

Dosing ranges are aggregated from preclinical research and community protocols. Not medical dosing guidance.

Administration Routes

Oral (capsule/liquid)

Reconstitution Notes

Oral compound — no reconstitution needed. Typically supplied as capsules or liquid solution. Store at room temperature away from light.

Step-by-step reconstitution guide →

Supplies you'll need

Insulin Syringes (U-100)Reconstitution Needles Lambda BAC Water Alcohol Prep Pads

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Reported Side Effects

Water retention
Increased appetite
Elevated fasting glucose (long-term)
Fatigue (initial, transient)
Carpal tunnel syndrome (high doses)
Elevated prolactin
Lethargy / morning grogginess

Research Papers

2 peer-reviewed sources

Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults

New England Journal of Medicine1996

MK-677 increases growth hormone and IGF-1 without affecting cortisol

Journal of Clinical Endocrinology & Metabolism1998

Community Experiences

Aggregated from public forums. Anecdotal — not clinical evidence.

r/Peptides

Community reports on oral dosing protocols, sleep improvements, and managing water retention with MK-677.

View original thread

r/PEDs

User experiences with ibutamoren for body composition and recovery.

View original thread

Overview

MK-677 (ibutamoren) is a non-peptide, orally active growth hormone secretagogue developed by Merck in the 1990s. Unlike GHRP peptides that require injection, MK-677 survives digestion due to its small-molecule structure and achieves systemic bioavailability after oral administration.

Its primary distinction is a ~24-hour half-life, enabling once-daily dosing — a major practical advantage over injectable GHRPs that must be dosed multiple times per day. This makes MK-677 one of the most convenient GH-stimulating compounds in the research toolkit.

Mechanism

MK-677 is a potent, selective agonist of the ghrelin receptor (GHS-R1a). By mimicking acylated ghrelin, it:

Stimulates pulsatile GH release from the anterior pituitary
Increases IGF-1 production in the liver (the primary anabolic mediator)
Does not suppress endogenous GH axis — the natural feedback loop remains intact
Increases appetite via NPY/AgRP hypothalamic neurons (the same pathway as ghrelin)

Unlike exogenous GH administration, MK-677 works through the natural pulsatile release mechanism, preserving the physiologic pattern of GH secretion.

GH Axis Effects

| Parameter | Effect | |-----------|--------| | GH pulse amplitude | ↑↑↑ | | IGF-1 | ↑↑↑ | | Cortisol | ↔ (minimal) | | Prolactin | ↑ (mild) | | Fasting insulin | ↑ (long-term concern) | | Appetite | ↑↑ |

Dosing Notes

10mg/day: Lower IGF-1 increase; fewer side effects; often used for sleep and recovery
25mg/day: Research-standard dose; significant IGF-1 elevation; moderate water retention
50mg/day: Maximum studied; greater water retention and glucose effects; used in short-cycle contexts

Timing: Best taken at night with food to blunt the appetite surge and allow GH pulse during sleep.

Glucose and Metabolic Considerations

A key finding in long-term MK-677 research is mild insulin resistance. GH itself is counter-regulatory to insulin, so sustained GH elevation can impair fasting glucose over weeks. This is the primary reason MK-677 cycles are limited in length and why metabolic monitoring is relevant in research protocols.