Comparison
GHRP-2 vs PT-141
Side-by-side of GHRP-2 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.
GHRP-2
GHRP-2 peptide (pralmorelin, KP-102) is a synthetic hexapeptide ghrelin-receptor agonist that triggers pulsatile growth hormone release via the pituitary.
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
GHRP-2
- •Hexapeptide ghrelin-receptor agonist that stimulates pulsatile GH release within 15 to 30 minutes
- •Strongest appetite signal among GHRPs at standard doses; centrally mediated via NPY/AgRP
- •Produces measurable cortisol and prolactin rise (more than ipamorelin, less than GHRP-6)
- •Approved in Japan as pralmorelin for GH-deficiency diagnostic provocation; not FDA approved
- •Anecdotal protocols use 100 to 300 mcg subcutaneously 2 to 3 times daily on an empty stomach
- •Banned by WADA under S2; detection methods validated in accredited labs
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 | GHRP-2 | PT-141 |
|---|---|---|
| Category | peptide | peptide |
| Also known as | Growth Hormone Releasing Peptide 2, Pralmorelin, KP-102, GPA-748 | Bremelanotide, Vyleesi |
| Half-life (hr) ↗ | 0.5 | 2.7 |
| Typical dose (mg) ↗ | 0.1 | 1.75 |
| Dosing frequency | 2-3x 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 | 817.97 | 1025.18 |
| Molecular formula | C45H55N9O6 | C50H68N14O10 |
| Mechanism | Hexapeptide agonist of the growth-hormone secretagogue receptor (GHS-R1a). Suppresses hypothalamic somatostatin tone and stimulates pituitary somatotrophs, producing a pulsatile GH release with secondary cortisol, prolactin, and ACTH elevation. | 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; approved in Japan as pralmorelin (diagnostic); research-use-only grey market in US/EU; 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 in US (research chemical); approved diagnostic in Japan | 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 | 158861-67-7 | 189691-06-3 |
| PubChem CID | 9919072 | 9941379 |
| Wikidata | Q7235681 | Q422059 |
Safety profile
GHRP-2
Common side effects
- acute hunger
- head pressure or flushing
- water retention
- vivid dreams
- tingling at injection site
- transient lethargy
Contraindications
- pregnancy
- active malignancy
- history of pituitary tumor
- uncontrolled diabetes
- severe insulin resistance
Interactions
- CJC-1295: synergistic GH release; commonly co-administered for larger pulse(minor)
- sermorelin: additive GH release via parallel GHRH and ghrelin pathways(minor)
- insulin: sustained GH can blunt insulin sensitivity over weeks(moderate)
- corticosteroids: blunt GH response and amplify cortisol load(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?
GHRP-2 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 GHRP-2.
- → If your priority is post-training recovery, pick GHRP-2.
- → 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; GHRP-2 is the safer pick if that applies.
Default choice: either is defensible. GHRP-2 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 GHRP-2 and PT-141?
GHRP-2 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, GHRP-2 or PT-141?
GHRP-2 half-life is 0.5 hours; PT-141 half-life is 2.7 hours.
Can you stack GHRP-2 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