Last updated: May 18, 2026
The fundamental difference
| Sermorelin | Ipamorelin | |
|---|---|---|
| Class | GHRH analog | GHRP (ghrelin agonist) |
| Receptor | GHRH receptor | GHS-R1a (ghrelin receptor) |
| Amino acids | 29 (GHRH 1-29) | 5 (synthetic pentapeptide) |
| Half-life | ~12 min | ~2 hours |
| Cortisol/prolactin effect | Minimal | Minimal |
| Appetite effect | None | Very mild |
How each works
Sermorelin tells the pituitary to make and release GH via the GHRH receptor pathway. Mimics endogenous GHRH.
Ipamorelin triggers release of stored GH from the pituitary via the ghrelin pathway.
Why they’re often stacked
GHRH + GHRP produces amplified GH release vs either alone. This is why CJC-1295 (a longer-acting GHRH analog) + Ipamorelin is more common than either monotherapy.
When to use which
- Sermorelin alone: Simple GHRH-mimetic, lower cost, multiple daily injections required
- Ipamorelin alone: Selective GHRP, lower cost than CJC-1295, fewer daily injections than sermorelin
- CJC-1295 + Ipamorelin: Synergistic combination, most-studied protocol
- Tesamorelin: FDA-approved alternative to sermorelin for visceral fat reduction
Is ipamorelin stronger than sermorelin?<br />
Different mechanisms make direct comparison hard. Ipamorelin produces a sharper GH pulse; sermorelin a more biomimetic GHRH-mediated release. Combined use is most effective.
Which has fewer side effects?<br />
Both have clean safety profiles. Ipamorelin is the cleanest GHRP class member. Sermorelin has the longest clinical history.
How often do I dose each?<br />
Sermorelin: 2-3x daily due to short half-life. Ipamorelin: 2-3x daily for pulse pattern, but longer half-life makes 1-2x daily possible.
Why use CJC-1295 instead of sermorelin?<br />
CJC-1295 is a longer-acting GHRH analog with much longer half-life (no DAC: ~30 min; with DAC: ~6 days). Convenience and stronger pituitary stimulation.