Growth Hormone Secretagogues

MK-677

Also known as: Ibutamoren · Nutrobal · MK677

Oral growth hormone secretagogue — the only GH stimulator you can take by mouth.

Half-Life
~24 hours
Administration
Oral
Category
Growth Hormone Secretagogues
Citations
1 studies

What is MK-677?

MK-677 (Ibutamoren) is an orally active, non-peptide ghrelin receptor agonist that stimulates GH and IGF-1 release. It is unique among GH secretagogues in that it is orally bioavailable — no injections required. It produces sustained GH and IGF-1 elevation and is widely used for anti-aging, muscle building, and sleep improvement.

Mechanism of Action

MK-677 mimics ghrelin by binding to GHSR-1a receptors in the pituitary and hypothalamus, stimulating GH release. Unlike injectable GHRPs, its oral bioavailability and long half-life produce sustained (rather than pulsatile) GH elevation. It also increases IGF-1 levels significantly.

MK-677 Dosing Protocol

10–25 mg/day oral, taken before bed (amplifies nocturnal GH pulse). Start at 10 mg to assess tolerance (hunger and water retention are common). Most users settle at 12.5–25 mg/day. Can be used long-term (months to years).

Administration Routes
Oral
Half-Life
~24 hours

Want a personalized protocol? Tell PepBot your goals, health status, and experience level for a custom MK-677 protocol.

MK-677 Benefits

Oral GH stimulation (no injections)
Increased GH and IGF-1 levels
Improved sleep quality (deep sleep)
Muscle gain and fat loss
Improved skin and hair quality
Bone density improvement
Anti-aging effects

Side Effect Profile

Increased hunger (significant — ghrelin mimetic), water retention, mild lethargy, potential insulin resistance with long-term use. Numbness/tingling (carpal tunnel-like) at higher doses. Generally well-tolerated.

MK-677 Stacking Guide

MK-677 works synergistically with these compounds. Click any to learn more, or ask PepBot to build you a complete stack.

Research & Citations

Frequently Asked Questions about MK-677

Does MK-677 suppress testosterone?
No — MK-677 does not suppress testosterone. It works through the GH axis, not the HPG (testosterone) axis. This is one of its major advantages over SARMs. It can be used without PCT and stacked with SARMs to add GH/IGF-1 benefits without additional hormonal suppression.

Still have questions about MK-677?

PepBot has encyclopedic knowledge of MK-677 — dosing, stacking, interactions, latest research, and personalized protocols. Ask anything.