A neutral, evidence-rated side-by-side of Ibutamoren (MK-677, GH secretagogue) and Ipamorelin. Figures are typical reference values, not recommendations.
| Ibutamoren (MK-677, GH secretagogue) | Ipamorelin | |
|---|---|---|
| Type | SARM | Peptide |
| Evidence level | Emerging | Limited |
| Primary class | Non-steroidal | Injectable |
| Half-life | ~24 hours | ~2 h |
| Typical dose | 20–25 mg/day | 100–300 mcg |
| Documented effects | 4 | 3 |
| Documented side effects | 4 | 3 |
Ibutamoren (MK-677) is a non-peptide growth hormone secretagogue, not a SARM, that raises GH and IGF-1 by mimicking ghrelin. It is the most human-studied compound in this group, with trials in older adults, GH-deficient patients and others. Its hallmark effects are increased appetite, water retention and higher IGF-1; it does not suppress testosterone, so no steroid profile applies.
Full Ibutamoren (MK-677, GH secretagogue) page →Ipamorelin is a selective pentapeptide growth-hormone secretagogue (a ghrelin/GHS-R agonist) that triggers a clean GH pulse with little effect on cortisol, prolactin or appetite. This selectivity makes it the most commonly used GHRP for body-composition purposes, usually stacked with a GHRH analogue. Human evidence is limited to early pharmacology; physique use is anecdotal.
Full Ipamorelin page →