Head to head
MK-677 against Somatropin
Raising your own growth hormone against injecting growth hormone itself. One is FDA-approved with defined indications; the other completed phase 3 and did not gain approval, which is a fact usually left out of the pitch for the oral option.
Column A
MK-677Ibutamoren (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.
Column B
SomatropinSomatropin (recombinant human growth hormone)
FDA-approved recombinant human growth hormone used for growth hormone deficiency and several other approved indications.
Side by side, on the facts we can check
| Attribute | MK-677 | Somatropin |
|---|---|---|
| Category | Growth Hormone | Growth Hormone |
| FDA status | Not FDA-approved (failed to gain approval after Phase 3) | FDA-approved for GH deficiency and other indications |
| Half-life | ~24 hours | ~3-4 hours (subcutaneous) |
| Molecular weight | 624.8 Da | 22,124 Da |
| Mechanism | Agonizes the ghrelin/GH secretagogue receptor (GHS-R1a), increasing GH and IGF-1 while also stimulating appetite. | Directly activates growth hormone receptors, raising IGF-1 and driving growth, protein synthesis, and metabolic effects. |
| Human studies cited | 3 | 2 |
| Legal status, US | Not approved; research use only | FDA-approved, prescription only |
Frequently asked questions
What is the difference between MK-677 and Somatropin?
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. Somatropin: FDA-approved recombinant human growth hormone used for growth hormone deficiency and several other approved indications.
Which has stronger research evidence, MK-677 or Somatropin?
This database does not grade compounds. It counts what was run in people: 3 of the 3 studies cited on the MK-677 profile were human work, against 2 of 3 for Somatropin. Those counts are of our own citation lists and understate any larger literature, and neither is a recommendation.
Are MK-677 and Somatropin FDA-approved?
MK-677: Not FDA-approved (failed to gain approval after Phase 3). Somatropin: FDA-approved for GH deficiency and other indications.
Related posts
Blog articles that cover MK-677 or Somatropin, newest first.
Reviewed Sep 2026. This page sets two published records side by side. It is educational, it is not medical advice, and it contains no dosing protocols or recommendations for personal use.