MK-677 vs Ipamorelin
An oral non-peptide secretagogue versus an injectable peptide.
Ibutamoren (oral ghrelin receptor agonist)
A non-peptide, orally active ghrelin receptor agonist that raises growth hormone and IGF-1. Completed but did not pass Phase 3 for approval.
Ipamorelin Acetate
A selective growth hormone secretagogue and ghrelin receptor agonist that stimulates pulsatile GH release with minimal effect on cortisol or prolactin.
| Attribute | MK-677 | Ipamorelin |
|---|---|---|
| Category | Growth Hormone | Growth Hormone |
| FDA status | Not FDA-approved (failed to gain approval after Phase 3) | Not FDA-approved |
| Half-life | ~24 hours | ~2 hours |
| Molecular weight | 624.8 Da | 711.85 Da |
| Mechanism | Agonizes the ghrelin/GH secretagogue receptor (GHS-R1a), increasing GH and IGF-1 while also stimulating appetite. | Agonizes the ghrelin/GH secretagogue receptor (GHS-R1a) on the pituitary, stimulating pulsatile growth hormone secretion. |
| Legal status (US) | Not approved; research use only | Not approved; research use only |
Frequently asked questions
What is the difference between MK-677 and Ipamorelin?
MK-677: A non-peptide, orally active ghrelin receptor agonist that raises growth hormone and IGF-1. Completed but did not pass Phase 3 for approval. Ipamorelin: A selective growth hormone secretagogue and ghrelin receptor agonist that stimulates pulsatile GH release with minimal effect on cortisol or prolactin.
Which has stronger research evidence, MK-677 or Ipamorelin?
MK-677 is rated Moderate and Ipamorelin is rated Moderate for evidence level in this database. Evidence level reflects the quality of published research, not a recommendation.
Are MK-677 and Ipamorelin FDA-approved?
MK-677: Not FDA-approved (failed to gain approval after Phase 3). Ipamorelin: Not FDA-approved.
Evidence levels reflect the quality of published research, not a recommendation. This comparison is educational and is not medical advice.