Comparison
Hexarelin vs PT-141
Side-by-side of Hexarelin 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.
Hexarelin
Hexarelin peptide is a ghrelin-receptor hexapeptide. Largest acute GH pulse in the GHRP class, highest cortisol and prolactin lift, CD36 cardioprotective sign.
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
Hexarelin
- •Synthetic hexapeptide GHS-R1a agonist; produces the largest acute GH pulse of the synthetic GHRP class
- •Independent CD36 signaling produces cardioprotective effects in rodent ischemia models, GH-independent
- •Pronounced tachyphylaxis: GH response attenuates over 2 to 4 weeks of daily dosing
- •More cortisol and prolactin elevation than GHRP-2 or ipamorelin
- •Anecdotal protocols use 100 to 200 mcg subcutaneously 1 to 2 times daily for 2 to 4 week pulses
- •Banned by WADA under S2; advanced through phase 2 trials but never reached registration
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 | Hexarelin | PT-141 |
|---|---|---|
| Category | peptide | peptide |
| Also known as | Examorelin, EP-23905, His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH2 | Bremelanotide, Vyleesi |
| Half-life (hr) ↗ | 1 | 2.7 |
| Typical dose (mg) ↗ | 0.1 | 1.75 |
| Dosing frequency | 1-2x daily | as needed (max once per 24 hours, max 8 per month) |
| Routes | subcutaneous, intranasal, intravenous | subcutaneous |
| Onset (hr) | 0.25 | 0.75 |
| Peak (hr) | 0.5 | 1.5 |
| Molecular weight | 887.04 | 1025.18 |
| Molecular formula | C47H58N12O6 | C50H68N14O10 |
| Mechanism | Hexapeptide agonist of GHS-R1a producing acute GH release with cortisol and prolactin co-elevation. Independent CD36 binding produces GH-independent cardioprotective signaling in preclinical models. | 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 2 trials in EU but never registered; 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 | 140703-51-1 | 189691-06-3 |
| PubChem CID | 3037387 | 9941379 |
| Wikidata | Q5743550 | Q422059 |
Safety profile
Hexarelin
Common side effects
- water retention
- vivid dreams
- head pressure or flushing
- transient lethargy
- tingling at injection site
- moderate hunger
Contraindications
- pregnancy
- active malignancy
- history of pituitary tumor
- uncontrolled diabetes
- prolactin-sensitive states
Interactions
- CJC-1295: synergistic GH release; accelerates tachyphylaxis if used continuously(minor)
- sermorelin: additive GH release via parallel GHRH and ghrelin pathways(minor)
- insulin: sustained GH can blunt insulin sensitivity over weeks(moderate)
- corticosteroids: amplify cortisol load; blunt GH response(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?
Hexarelin 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 Hexarelin.
- → If your priority is post-training recovery, pick Hexarelin.
- → 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; Hexarelin is the safer pick if that applies.
Default choice: either is defensible. Hexarelin 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 Hexarelin and PT-141?
Hexarelin 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, Hexarelin or PT-141?
Hexarelin half-life is 1 hours; PT-141 half-life is 2.7 hours.
Can you stack Hexarelin 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