Side-by-Side Comparison · 2026

MK-677 vs Sermorelin

MK-677 vs Sermorelin — mechanism, half-life, dosing, and research status compared. Which is right for your protocol?

MK-677
Growth Hormone & IGF

MK-677 (ibutamoren) is an orally active, non-peptide ghrelin receptor agonist (GHS-R1a) that stimulates GH release from the pituitary without requiring injection. It was developed by Merck and advanced through Phase II trials for growth hormone deficiency, muscle wasting, and fra...

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Sermorelin
Growth Hormone

Sermorelin is a synthetic analog of the first 29 amino acids of endogenous GHRH, retaining full biological activity at the GHRH receptor. It was FDA approved (Geref) for GH deficiency in children from 1997 until its voluntary market withdrawal in 2008 for commercial reasons - not...

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Key Parameters
Parameter MK-677 Sermorelin
Category Growth Hormone & IGF Growth Hormone
Research Phase II (Discontinued) Extensively Studied
Half-Life ~24 hours ~10–20 min
Typical Dose 10–25 mg 200–500 µg
Frequency Once daily Once daily (bedtime)
Route Oral Subcutaneous
FDA Status Not Approved Compounding Only

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Frequently Asked Questions
What is the difference between MK-677 and Sermorelin?
MK-677: MK-677 (ibutamoren) is an orally active, non-peptide ghrelin receptor agonist (GHS-R1a) that stimulates GH release from the pituitary without requiring injection. It was developed by Merck and advance... Sermorelin: Sermorelin is a synthetic analog of the first 29 amino acids of endogenous GHRH, retaining full biological activity at the GHRH receptor. It was FDA approved (Geref) for GH deficiency in children from...
Which has a longer half-life, MK-677 or Sermorelin?
MK-677 half-life: ~24 hours. Sermorelin half-life: ~10–20 min.
Can you stack MK-677 and Sermorelin?
MK-677 and Sermorelin are sometimes used together in research protocols. Always consult relevant literature and follow appropriate guidelines.

For research use only. Not medical advice. ASCEND does not conduct or endorse any specific research protocol. Always consult relevant scientific literature and regulatory guidelines.