AOD-9604 vs PT-141
A neutral, side-by-side comparison of two metabolic peptides — their mechanisms, dosing ranges, administration routes, side effects, and research evidence. For research and educational purposes only.
AOD-9604
AOD-9604 is a modified fragment of the C-terminus of human growth hormone (hGH), specifically amino acids 176–191. It was developed to replicate the fat-metabolizing activity of hGH without the growth-promoting, insulin-desensitizing, or mitogenic effects of full-length hGH. Research has focused on its ability to stimulate lipolysis and inhibit lipogenesis through a non-GHR-dependent mechanism.
Full profilePT-141
PT-141 (Bremelanotide) is a synthetic melanocortin receptor agonist FDA-approved for hypoactive sexual desire disorder (HSDD) in premenopausal women. It acts centrally on the nervous system rather than peripherally, distinguishing it mechanistically from PDE5 inhibitors like sildenafil.
Full profile| AOD-9604 | PT-141 | |
|---|---|---|
| Category | Metabolic | Metabolic |
| Also known as | Anti-Obesity Drug 9604, hGH Fragment 176-191, Tyr-hGH Frag 176-191 | Bremelanotide, Vyleesi, Melanocortin receptor agonist |
| Evidence | Investigational (in trials) | FDA-approved |
| Dosing range | 250mcg–1000mcg mcg, Once daily, on an empty stomach | 0.5mg–2mg mg, as needed, 45 minutes before activity (max 1x per 24h) |
| Administration | Subcutaneous injection, Oral (significantly reduced bioavailability) | Subcutaneous injection, Intranasal (historical — discontinued due to BP concerns) |
| Key side effects | Injection site redness or irritation, Mild flushing (transient), Headache (rare), Considered low side-effect profile compared to full hGH | Nausea (most common — ~40% in trials), Flushing, Headache, Transient blood pressure elevation |
| Cited sources | 3 references | 1 reference |
Key differences
- Evidence level differs: AOD-9604 is investigational (in trials), while PT-141 is fda-approved.
- Administration: AOD-9604 — Subcutaneous injection, Oral (significantly reduced bioavailability); PT-141 — Subcutaneous injection, Intranasal (historical — discontinued due to BP concerns).
- Dosing units differ: AOD-9604 is dosed in mcg, PT-141 in mg — they operate at different scales.
- Frequency: AOD-9604 is typically Once daily, on an empty stomach; PT-141 is as needed, 45 minutes before activity (max 1x per 24h).
- Research depth: this profile cites 3 sources for AOD-9604 vs 1 for PT-141.
How each works
AOD-9604
Animal studies consistently demonstrate that AOD-9604 reduces body fat in obese rodents without affecting blood glucose or IGF-1 levels — a significant distinction from hGH. It appears to act directly on fat cells via beta-adrenergic pathways. Phase 2 human clinical trials for obesity were conducted but did not meet primary endpoints for the oral formulation; injectable forms were not advanced to Phase 3. AOD-9604 received GRAS (Generally Recognized As Safe) status in the US for food use, though this does not confer therapeutic approval.
PT-141
PT-141 activates MC3R and MC4R receptors in the hypothalamus, triggering downstream sexual arousal pathways independent of vascular effects. Phase 3 trials supporting Vyleesi approval showed statistically significant improvements in desire and reductions in distress in women with HSDD. Off-label research explores use in men with erectile dysfunction refractory to PDE5 inhibitors.
This comparison aggregates public research and structured profile data for informational purposes only. It is not medical advice and does not recommend either compound for human use. Consult a qualified healthcare provider before considering any peptide.