MK-677

From Retapedia, the free peptide encyclopedia
"MK-677" redirects here. For other uses, see MK-677 (disambiguation).
Medical disclaimer. This article is for informational purposes only and does not constitute medical advice. Consult a qualified clinician before considering any compound discussed below. See Retapedia : Medical disclaimer.

MK-677 (also known as MK-677 or Ibutamoren) is a therapeutically researched peptide studied for its effects on growth hormone, muscle gain, sleep. Oral ghrelin receptor agonist boosting GH/IGF-1 and sleep quality. Causes insulin resistance and glucose issues. Not FDA-approved, development discontinued.

Ibutamoren (MK-677) is a potent, long-acting, orally-active, selective non-peptide agonist of the ghrelin receptor (GHS-R1a) and growth hormone secretagogue. It mimics ghrelin's action by binding to receptors in the hypothalamus and pituitary gland, increasing growth hormone secretion by 50-97% and significantly elevating IGF-1 levels while preserving natural pulsatile GH secretion patterns. Clinical trials in elderly populations demonstrated significant increases in lean body mass (1.1 kg gain vs 0.5 kg loss with placebo over 12 months), improved bone mineral density, and enhanced markers of bone formation.

Natty status
MK-677 is generally regarded as compatible with natural bodybuilding, though competitive federations may differ. See § Natty status.
Contents [hide]
  1. 1 Overview
  2. 2 Mechanism of action
  3. 3 Reported effects
  4. 4 Dosage and administration
  5. 5 Natty status
  6. 6 Research
  7. 7 Related compounds
  8. 8 References
  9. 9 External links

Overview

Notable for dramatically improving sleep quality with 20-50% increases in REM sleep and 50% increases in slow-wave sleep.

However, ibutamoren consistently impairs glucose metabolism, causing fasting blood glucose elevation, decreased insulin sensitivity, and increased HbA1c in multiple trials, leading to dose reductions or discontinuation.

One clinical trial was terminated due to serious adverse events including cardiovascular concerns and congestive heart failure cases in elderly patients.

Not FDA-approved and development appears discontinued due to safety concerns, particularly cardiovascular risks and metabolic effects.

Common side effects include increased appetite, water retention, insulin resistance, and potential increased cancer risk from elevated IGF-1.

Recommended 8-12 week cycles at 10-25mg daily, typically taken before bed for sleep benefits.

Mechanism of action

Increases lean muscle mass, bone density, and deep sleep quality. Enhances recovery and tissue healing. Risk of blood sugar issues.

Reported effects

Effects reported in the literature and from preclinical models include:

  • Preliminary data support the use of ibutamoren as an oral growth hormone secretagogue in children with partial GH deficiency, reviewed alongside long-acting GH preparations in 2025 pediatric endocrinology literature. [1] Phase I

Evidence grades: FDA approved Phase III Phase II Phase I Preclinical Anecdotal

Dosage and administration

⚠
Dosage information is included for encyclopedic purposes only. Retapedia does not provide medical advice. See Retapedia : Medical disclaimer.

Low dose

  • 10-15mg daily (ideal for sleep, longevity, first-time users)

Moderate dose

  • 20-25mg daily (clinical trial standard, body recomposition)

High dose

  • 30mg+ daily (advanced users, not recommended due to side effects)

Timing

  • Before bed: Maximizes sleep benefits, reduces daytime hunger
  • Morning: Increases appetite throughout day (useful for bulking)

Cycle duration

  • 8-12 weeks recommended, up to 16 weeks for intermediate

Half

  • life: 24 hours (once daily dosing sufficient)

General

  • Monitor fasting glucose and insulin sensitivity during use

Natty status

See also: Peptide § Natty status

MK-677 is generally regarded as compatible with the natty designation, particularly when used for therapeutic healing purposes. Opinions vary across natural bodybuilding federations, and athletes who compete should consult the rulebook of their respective sanctioning body.[2]

Research

1 active clinical trial on record — highest phase: Phase 3
View on ClinicalTrials.gov · fetched May 25, 2026

The peptide has been the subject of 9 studies and reference works collected on this site. The full bibliography is in § External links below.

Other peptides in this catalogue with overlapping mechanisms or status:

CJC-1295/Ipamorelin Stack Natty
Boosts growth hormone 3-5x higher than individual peptides. Improves sleep quality, muscle mass, fat loss, and recovery. Minimal side effects.
Ipamorelin Natty
Stimulates growth hormone release without cortisol/prolactin effects. Improves sleep quality, recovery, and body composition. Minimal side effects.
IGF-1 LR3 Natty
Powerfully increases muscle growth, protein synthesis, and fat burning. Accelerates tissue repair and recovery. Risk of hypoglycemia.
NAD+ Natty
Boosts cellular energy production and DNA repair. Activates longevity enzymes. Improves metabolism and mitochondrial health. Cellular benefits proven, human longevity unproven.

References

  1. ^ New directions in growth hormone treatment in children. Recent review
  2. a b World Anti-Doping Agency. (2026). Prohibited List 2026.

External links

Categories: Peptides | Therapeutic peptides | Growth hormone | Muscle gain | Sleep | Bone density

This page was last edited on May 25, 2026, at 01:14 (UTC).

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