Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.
| Ipamorelin | PT-141 (Bremelanotide) | |
|---|---|---|
| Category | Peptides | Peptides |
| Standard Dose | Research indicates 200-300 mcg administered 1-3 times daily via subcutaneous injection. | Research indicates 1.75 mg administered via subcutaneous injection approximately 45 minutes before anticipated sexual activity. |
| Timing | Best administered at bedtime for synergy with natural GH peak. Also effective upon waking and post-workout. Always on empty stomach. | 45-60 minutes before anticipated sexual activity. Effects last 6-72 hours depending on individual response. |
| Cycle Duration | 12-24 week cycles with 4-8 week breaks. | As-needed basis. Not intended for daily use. |
| 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.
PT-141 (Bremelanotide) is a synthetic cyclic heptapeptide melanocortin analog that acts as an agonist at MC3R and MC4R melanocortin receptors, with higher affinity for MC4R. It enhances sexual desire by activating presynaptic MC4Rs on neurons in the medial preoptic area (mPOA) of the hypothalamus, increasing dopamine release — an excitatory neurotransmitter for sexual desire. Unlike PDE5 inhibitors, PT-141 works centrally through the CNS rather than peripherally on blood flow, addressing desire rather than just erectile mechanics.
Research indicates 1.75 mg administered via subcutaneous injection approximately 45 minutes before anticipated sexual activity.
45-60 minutes before anticipated sexual activity. Effects last 6-72 hours depending on individual response.
As-needed basis. Not intended for daily use.
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