# MK-677 (Ibutamoren)

*Also known as: Ibutamoren, MK677, MK 677, Nutrobal*

Orally active growth hormone secretagogue (ghrelin receptor agonist) that elevates GH and IGF-1; the non-peptide counterpart to injectable GHRPs.

## Overview

MK-677 (ibutamoren) is an orally active, non-peptide growth hormone secretagogue that mimics ghrelin at the GHS-R1a receptor to elevate growth hormone and IGF-1 levels. Unlike the injectable GHRPs, it is taken by mouth, which is a large part of its appeal. Its half-life is roughly five hours with around 60% bioavailability, which in research contexts supports once-daily dosing. MK-677 actually has a deeper human evidence base than most compounds on this list, with multiple Phase 2 trials examining it for frailty, osteoporosis, and growth hormone deficiency. It did not gain approval, and long-term safety data remains limited. Common effects include increased appetite, transient water retention, and elevated fasting blood glucose, so the risk profile is real and worth tracking.

## Pharmacokinetics

- **Model tier:** simple
- **Half-life:** 0.2 days (5 hours)
- **Bioavailability:** 60%

## Dosing

- **Default dose:** 15 mg
- **Typical range:** 10–25 mg
- **Units:** ng/mL

## Source

- **Label:** Nass et al. (PMC2757071) + DrugBank
- **URL:** https://pmc.ncbi.nlm.nih.gov/articles/PMC2757071/
- **Notes:** Orally-active non-peptide GH secretagogue; parent half-life ~4-6h, terminal ~24h. Bioavailability ~60%.

**Tags:** muscle-building, recovery-healing, anti-aging-longevity

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**Canonical URL:** https://anabolicdex.com/compounds/mk-677
**Plot:** https://anabolicdex.com/plot?compound=mk-677