Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.
| Ipamorelin | Sermorelin | |
|---|---|---|
| Category | Peptides | Peptides |
| Standard Dose | Research indicates 200-300 mcg administered 1-3 times daily via subcutaneous injection. | Research indicates 200-300 mcg administered once daily at bedtime via subcutaneous injection. |
| Timing | Best administered at bedtime for synergy with natural GH peak. Also effective upon waking and post-workout. Always on empty stomach. | Bedtime administration (aligns with natural nocturnal GH release). On empty stomach. |
| Cycle Duration | 12-24 week cycles with 4-8 week breaks. | 12-24 week cycles. Some protocols use continuous treatment. |
| Evidence Level | moderate_human | strong_human |
Ipamorelin is a pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) that acts as the first selective growth hormone secretagogue receptor (GHS-R1a/ghrelin receptor) agonist. Unlike other GHRPs, it selectively stimulates GH release without significantly affecting ACTH, cortisol, prolactin, or aldosterone — even at doses 200-fold above the ED50 for GH release. This selectivity profile is comparable to GHRH itself but operates through the distinct ghrelin receptor on pituitary somatotrophs.
Research indicates 200-300 mcg administered 1-3 times daily via subcutaneous injection.
Best administered at bedtime for synergy with natural GH peak. Also effective upon waking and post-workout. Always on empty stomach.
12-24 week cycles with 4-8 week breaks.
Sermorelin is a synthetic 29-amino acid peptide representing the biologically active fragment of GHRH (amino acids 1-29) with full functional activity. It activates GHRH receptors on pituitary somatotrophs, stimulating cAMP production via Gs protein/adenylate cyclase and MAP kinase pathways. Due to the interactive effects of sermorelin and endogenous somatostatin, GH release is episodic rather than continuous. Sermorelin also stimulates pituitary gene transcription of GH mRNA, increasing and preserving pituitary GH reserve.
Research indicates 200-300 mcg administered once daily at bedtime via subcutaneous injection.
Bedtime administration (aligns with natural nocturnal GH release). On empty stomach.
12-24 week cycles. Some protocols use continuous treatment.
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