MK-677 (Ibutamoren)
Also known as: Ibutamoren · Ibutamoren mesylate · MK-0677 · L-163,191
An orally active, non-peptide growth-hormone secretagogue studied for its ability to raise growth hormone and IGF-1 levels by mimicking the hormone ghrelin.
MK-677 (Ibutamoren) at a glance
| Name | MK-677 (Ibutamoren) |
|---|---|
| Also known as | Ibutamoren, Ibutamoren mesylate, MK-0677, L-163,191 |
| Category | Growth-hormone axis |
| Type | Peptide |
| Sequence | Non-peptide small molecule (ghrelin-receptor agonist) |
| Typical dose | ~10-25 mg per day |
| Frequency | Once daily, commonly at night |
| Route | Oral (research) |
| Half-life | Approximately 4-6 hours, supporting once-daily oral use in the literature. |
Overview
MK-677 is a small-molecule compound that acts as an agonist at the ghrelin receptor (GHSR) rather than a true peptide. Because it is orally bioavailable, it has been investigated in human trials as a way to sustain elevated growth-hormone and IGF-1 output without injection. Studies have looked at its effects on body composition, appetite and, in older adults, muscle and bone parameters. It remains an investigational compound and is not an approved medicine.
How it’s thought to work
- Acts as an agonist at the growth-hormone secretagogue receptor (GHSR), mimicking ghrelin.
- Appears to stimulate pulsatile release of growth hormone from the pituitary.
- Downstream elevation of IGF-1 is thought to mediate many of its studied effects.
- Also stimulates appetite through central ghrelin-receptor activity.
Researched uses
- Raising growth-hormone and IGF-1 levels in clinical research
- Effects on lean body mass and body composition
- Investigated for age-related decline in muscle and bone
Commonly cited protocol
| Typical dose | ~10-25 mg per day |
|---|---|
| Frequency | Once daily, commonly at night |
| Route | Oral (research) |
| Notes | Oral dosing is frequently cited because the compound is not injected. |
Reconstitution
Typically supplied as capsules or an oral solution rather than a lyophilized vial, so insulin-syringe unit math does not apply.
Cautions
- A research chemical not approved by the FDA for human use; banned by WADA in sport.
- Reported to increase appetite and, in some studies, fasting glucose and insulin resistance.
- Can cause water retention and transient edema in the published literature.
- Long-term safety in healthy people is not well established.
MK-677 (Ibutamoren) FAQ
What is MK-677 (Ibutamoren)?
An orally active, non-peptide growth-hormone secretagogue studied for its ability to raise growth hormone and IGF-1 levels by mimicking the hormone ghrelin.
How does MK-677 (Ibutamoren) work?
Acts as an agonist at the growth-hormone secretagogue receptor (GHSR), mimicking ghrelin. Appears to stimulate pulsatile release of growth hormone from the pituitary. Downstream elevation of IGF-1 is thought to mediate many of its studied effects. Also stimulates appetite through central ghrelin-receptor activity.
What is MK-677 (Ibutamoren) used for?
Raising growth-hormone and IGF-1 levels in clinical research; Effects on lean body mass and body composition; Investigated for age-related decline in muscle and bone.
What is a typical MK-677 (Ibutamoren) dose?
~10-25 mg per day, Once daily, commonly at night, Oral (research). This is a commonly cited figure for context only, not medical advice.
How do you reconstitute MK-677 (Ibutamoren)?
Typically supplied as capsules or an oral solution rather than a lyophilized vial, so insulin-syringe unit math does not apply.
What is the half-life of MK-677 (Ibutamoren)?
Approximately 4-6 hours, supporting once-daily oral use in the literature.