Comparison
Ipamorelin vs PT-141
Side-by-side of Ipamorelin and PT-141. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
Ipamorelin
Ipamorelin peptide benefits: selective ghrelin-receptor GHRP, 200 to 300 mcg dosage, GH pulse without cortisol or prolactin rise, CJC-1295 stack vs sermorelin.
PT-141
PT-141 peptide (bremelanotide, Vyleesi): MC4R agonist for libido and erectile dysfunction. 1.75 mg subcutaneous, 30 to 60 min onset, 2 to 4 h half-life.
Effects at a glance
Ipamorelin
- •Pentapeptide GHS-R1a agonist with the cleanest selectivity profile in the GHRP class
- •Minimal cortisol and prolactin elevation at standard doses (substantially less than GHRP-2 or hexarelin)
- •~2 hour plasma half-life, longest of the synthetic GHRPs
- •Largest human safety database (~600 participants in Helsinn's postoperative ileus phase 2)
- •Standard pairing for CJC-1295 no-DAC at 200 to 300 mcg subcutaneously 2 to 3 times daily
- •Banned by WADA under S2; never reached registration despite phase 2b development
PT-141
- •Cyclic 7-amino-acid synthetic peptide and melanocortin receptor agonist (MC4R-preferring)
- •FDA approved in 2019 as Vyleesi for hypoactive sexual desire disorder in pre-menopausal women
- •Acts centrally on hypothalamic sexual-desire circuits rather than peripherally on vasculature
- •On-demand dosing: subcutaneous 1.75 mg approximately 45 minutes before sexual activity
- •Common adverse effects: nausea (~40%), flushing, headache, injection-site reactions, hyperpigmentation
- •Off-label male ED use is documented but not FDA approved; mechanism is distinct from PDE5 inhibitors
Side-by-side
| Attribute | Ipamorelin | PT-141 |
|---|---|---|
| Category | peptide | peptide |
| Also known as | NNC 26-0161, Aib-His-D-2-Nal-D-Phe-Lys-NH2 | Bremelanotide, Vyleesi |
| Half-life (hr) ↗ | 2 | 2.7 |
| Typical dose (mg) ↗ | 0.2 | 1.75 |
| Dosing frequency | 2-3x daily | as needed (max once per 24 hours, max 8 per month) |
| Routes | subcutaneous, intravenous | subcutaneous |
| Onset (hr) | 0.25 | 0.75 |
| Peak (hr) | 1 | 1.5 |
| Molecular weight | 711.86 | 1025.18 |
| Molecular formula | C38H49N9O5 | C50H68N14O10 |
| Mechanism | Selective GHS-R1a agonist that stimulates pulsatile GH release with minimal cortisol or prolactin co-activation. Suppresses hypothalamic somatostatin and stimulates pituitary somatotrophs. | Synthetic agonist of melanocortin receptors with preference for MC4R, expressed in hypothalamic and limbic circuits regulating sexual motivation. Engages central pathways distinct from peripheral PDE5-mediated vasodilation. |
| Legal status | Not FDA approved; advanced through phase 2b in postoperative ileus before discontinuation; research-use-only grey market; banned by WADA | Prescription only as Vyleesi; FDA-approved 2019 for HSDD in pre-menopausal women. Compounded versions sold off-label for male sexual function are research-use-only grey market. |
| WADA status | banned | allowed |
| DEA / Rx | Not scheduled (research chemical) | Rx only (not a controlled substance) for the FDA-approved Vyleesi formulation |
| Pregnancy | Insufficient data; not recommended | Not recommended; contraindicated during pregnancy per Vyleesi label |
| CAS | 170851-70-4 | 189691-06-3 |
| PubChem CID | 11338566 | 9941379 |
| Wikidata | Q1666741 | Q422059 |
Safety profile
Ipamorelin
Common side effects
- injection-site irritation
- vivid dreams
- transient mild head pressure
- occasional headache
Contraindications
- pregnancy
- active malignancy
- history of pituitary tumor
- uncontrolled diabetes
Interactions
- CJC-1295: synergistic GH release via parallel GHRH and ghrelin pathways; standard pairing(minor)
- sermorelin: additive GH release; functionally similar pairing to CJC-1295 with shorter GHRH half-life(minor)
- insulin: sustained GH can blunt insulin sensitivity over weeks(moderate)
- corticosteroids: blunt GH response; reduce expected efficacy(moderate)
PT-141
Common side effects
- nausea (~40%)
- flushing
- headache
- injection-site reactions
- hyperpigmentation (focal, gums, face, breasts)
- transient blood pressure increase (~6 mmHg systolic)
Contraindications
- uncontrolled hypertension
- established cardiovascular disease
- pregnancy
- naltrexone co-administration (reduces opioid efficacy due to MC receptor crosstalk)
Interactions
- naltrexone (oral): bremelanotide reduces oral naltrexone exposure significantly; avoid co-administration(major)
- antihypertensives: transient BP rise after bremelanotide can offset BP control(moderate)
- PDE5 inhibitors (sildenafil, tadalafil): no documented adverse interaction; mechanisms are non-overlapping(minor)
Which Should You Take?
Ipamorelin and PT-141 score evenly on the criteria we weight (goal breadth, legal accessibility, evidence depth). The conditionals below should drive the decision more than any aggregate score.
- → If your priority is growth-hormone axis, pick Ipamorelin.
- → If your priority is post-training recovery, pick Ipamorelin.
- → If your priority is sexual function, pick PT-141.
- → If your priority is libido, pick PT-141.
Edge case: PT-141 is contraindicated in pregnancy; Ipamorelin is the safer pick if that applies.
Default choice: either is defensible. Ipamorelin edges out on goal breadth + legal accessibility; PT-141 is the right call if your priority sits in the goals listed above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between Ipamorelin and PT-141?
Ipamorelin and PT-141 differ in category (peptide vs peptide), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Ipamorelin or PT-141?
Ipamorelin half-life is 2 hours; PT-141 half-life is 2.7 hours.
Can you stack Ipamorelin with PT-141?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper