Ibutamoren (MK-677)
An oral ghrelin receptor agonist that stimulates sustained GH and IGF-1 elevation.
Medically reviewed by Dr. Jonathan Snipes, MD. Last reviewed May 6, 2026.What It Is
Ibutamoren (MK-677) is an oral compound that mimics ghrelin, stimulating growth hormone release. It's unique because it's taken as a capsule, not an injection.
How It Works
By activating the ghrelin receptor, it signals the pituitary to release GH. Unlike injectable peptides, its effects last 24 hours per dose, maintaining elevated GH and IGF-1.
Who It's For
Those who prefer oral dosing over injections. People looking for sustained GH elevation for muscle growth, recovery, and sleep improvement.
Who Should Avoid It
May increase appetite significantly. Monitor blood sugar. Not for diabetics without careful management. Avoid with active cancer.
Protocol & Pricing
OBP Pharmacy Price
From $1.65/cap
You pay pharmacy price. No markup.
Starting Dose
12.5-25mg/day
Form
Capsule (12.5mg or 25mg)
Dosing Protocol
1 capsule daily, taken in the evening to align with natural GH peak. Start at 12.5mg and assess tolerance.
Beyond Use Date
180 Days from compounding (USP <797>)
Use within this window from the date your vial is compounded. BUD is set per USP <797> sterile compounding standards and printed on every label.
Stacking Guide
Stacks Well With
Related Peptides
Common questions about Ibutamoren (MK-677)
- What is ibutamoren (MK-677)?
- Ibutamoren (also known as MK-677) is an orally active small-molecule ghrelin receptor agonist that stimulates pituitary growth hormone release. Despite the molecule often being lumped with peptides, it is not technically a peptide; it is a small-molecule mimetic of the ghrelin receptor's natural ligand. It has been studied for sarcopenia, growth hormone deficiency, and recovery support.
- Is MK-677 a peptide, a SARM, or a steroid?
- None of those. MK-677 is a small-molecule ghrelin receptor agonist (a growth hormone secretagogue). It does not contain a peptide bond, does not bind androgen receptors (so it is not a SARM), and does not contain a steroid backbone. It is regulated as an investigational compound; WADA banned it for elite competitive sport.
- Is MK-677 safe?
- MK-677 has been studied in clinical trials at doses of 25 mg per day for up to 12 months without serious adverse events. Common side effects include increased appetite (the ghrelin-agonist mechanism), mild fluid retention, transient elevations in fasting glucose, and occasional next-day grogginess if dosed too late. Patients with diabetes or pre-diabetes should use MK-677 with provider monitoring of fasting glucose and HbA1c.
- How is MK-677 dosed?
- Common oral protocols deliver 10 to 25 mg once daily. Most patients dose in the evening to align the GH pulse with natural overnight release and to limit daytime appetite increase. Optimal Balance Pharmacy compounds MK-677 in capsule form against PeptideRx prescriptions; your provider sets the dose based on your goals.
- Does MK-677 affect testosterone or natural GH production long-term?
- MK-677 does not directly affect testosterone or the HPG axis the way exogenous testosterone or anabolic steroids do. It works on the ghrelin receptor to stimulate the body's own GH release, so it preserves the negative feedback loop of natural pulsatile GH. Long-term continuous use can cause some adaptation in receptor sensitivity; cycling protocols (8 to 12 weeks on, 4 weeks off) are common.