Comparison
AOD-9604 vs PT-141
Side-by-side of AOD-9604 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.
AOD-9604
AOD 9604 peptide: 16-amino-acid hGH fragment 176-191. Preclinical lipolytic activity, phase 2 obesity trial showed no weight loss vs placebo.
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
AOD-9604
- •Modified 16-amino-acid synthetic fragment of human growth hormone (residues 176-191)
- •Preclinical models show lipolytic activity in adipose tissue without GH-axis growth effects
- •Phase 2 obesity trial (Heffernan 2001) showed no significant weight-loss difference versus placebo
- •Anecdotal protocols use 250 to 500 mcg subcutaneously daily on an empty stomach
- •No FDA approval; the obesity drug development program was discontinued in 2007
- •Granted GRAS status in some jurisdictions for compounded use; not validated for fat loss in humans
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 | AOD-9604 | PT-141 |
|---|---|---|
| Category | peptide | peptide |
| Also known as | hGH fragment 176-191, Human Growth Hormone Fragment 176-191 | Bremelanotide, Vyleesi |
| Half-life (hr) ↗ | 0.5 | 2.7 |
| Typical dose (mg) ↗ | 0.3 | 1.75 |
| Dosing frequency | daily | as needed (max once per 24 hours, max 8 per month) |
| Routes | subcutaneous | subcutaneous |
| Onset (hr) | 1 | 0.75 |
| Peak (hr) | 2 | 1.5 |
| Molecular weight | 1815.17 | 1025.18 |
| Molecular formula | C78H125N23O23S2 | C50H68N14O10 |
| Mechanism | Modified C-terminal fragment of human growth hormone proposed to stimulate beta-3 adrenergic receptor signaling in adipocytes, increasing lipolysis and fatty-acid oxidation without engaging the GH receptor or activating IGF-1. | 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; research-use-only grey market in most jurisdictions | 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 | unknown | allowed |
| DEA / Rx | Not FDA approved; not scheduled; research-chemical status | 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 | 221231-10-3 | 189691-06-3 |
| PubChem CID | 71300630 | 9941379 |
| Wikidata | Q4654106 | Q422059 |
Safety profile
AOD-9604
Common side effects
- injection-site reactions
- transient mild headache (anecdotal)
- minimal in clinical trials
Contraindications
- pregnancy
- lactation
- no established human safety profile for chronic use
Interactions
- beta-blockers: theoretical antagonism of beta-3 adrenergic lipolytic signaling(minor)
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?
PT-141 comes out ahead for most readers on the criteria we weight: 2 catalogued goals, research-only / gray-market sourcing, with a Tier-A outcome catalogued. AOD-9604 is the right call when one of the conditionals below applies.
- → If your priority is fat loss, pick AOD-9604.
- → If your priority is body composition, pick AOD-9604.
- → 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; AOD-9604 is the safer pick if that applies.
Default choice: PT-141. Wider use case, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for AOD-9604 only if your priority sits squarely in the goals it owns 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 AOD-9604 and PT-141?
AOD-9604 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, AOD-9604 or PT-141?
AOD-9604 half-life is 0.5 hours; PT-141 half-life is 2.7 hours.
Can you stack AOD-9604 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.
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