What is AOD-9604?
AOD-9604 (Anti-Obesity Drug 9604) is a synthetic fragment of human growth hormone (hGH), corresponding to amino acids 176–191 of the C-terminal end with an additional tyrosine modification at the N-terminal position.
It was developed by Metabolic Pharmaceuticals in Australia with the specific goal of isolating the lipolytic (fat-burning) effects of hGH without the adverse metabolic effects of the full hormone:
| Feature | Full hGH | AOD-9604 |
|---|---|---|
| Lipolysis (fat burning) | ✅ | ✅ |
| Anabolic effects (muscle mass) | ✅ | ❌ |
| IGF-1 elevation | ✅ | ❌ |
| Insulin resistance | ✅ (at high doses) | ❌ |
| Fluid retention | ✅ | ❌ |
Lipolytic mechanism of action
AOD-9604 acts on the beta-3 adrenergic receptor in adipose tissue, activating hormone-sensitive lipase (HSL) which releases stored fatty acids from adipocytes. It also inhibits lipogenesis (new fat formation).
This mechanism is specific to adipose tissue, which explains why it does not produce the systemic effects of full hGH.
Clinical trials
Metabolic Pharmaceuticals completed Phase 1 and Phase 2 trials:
- Phase 1: No significant adverse effects at doses up to 1 mg/day oral.
- Phase 2 (12 weeks): Statistically significant fat loss vs. placebo, with no effects on glucose, IGF-1, or cardiovascular parameters.
- The Phase 2B trial did not achieve sufficient statistical significance to justify Phase 3, and the program was discontinued for commercial reasons, not safety concerns.
GRAS classification
In 2014, the FDA classified AOD-9604 as GRAS (Generally Recognized as Safe) for oral use in functional foods — an unusual distinction for a research peptide that implies a solid safety record at oral doses.
Frequently asked questions — Evidence-based objections
”Will I lose muscle?”
AOD-9604 does not activate protein synthesis or the anabolic effects of hGH. Muscle loss in Phase 2B studies is minimal (12-week studies only, no long-term data published). No published % breakdown. Mitigation: protein ≥1.6 g/kg + strength training.
”Does fatty liver improve?”
Fatty liver changes were not measured in published Phase 2B trials. AOD-9604 acts on systemic adipose tissue, not specifically on the liver. The mechanism (beta-3 lipolysis) is general, not hepatic-specific.
”What happens when I stop?”
No human withdrawal data (Phase 2B never completed). ~30 min half-life subcutaneously suggests rapid clearance. Expected: partial weight rebound once caloric deficit ends, similar to other lipolytic agents.
”Is it safe?”
FDA GRAS classification (2014) is the strongest endorsement of safety profile. Phase 1 and 2 showed no significant adverse effects. Program discontinued for commercial reasons, not safety. No reports of pancreatic or thyroid harm in trials.
Reconstitution (reference)
With 2 mg + 1.0 mL bacteriostatic water: 1 unit on a U-100 syringe ≈ 10 mcg.
Not approved for clinical use. For research use only. Trials were discontinued for commercial reasons. The safety profile is among the best documented of metabolic research peptides.
Reported protocol (research reference)
| Vial sizes | 2 mg, 5 mg |
|---|---|
| Reported dose | Clinical trials used 1 mg/day oral or 250–500 mcg subcutaneous/day. No currently approved protocol. |
| Half-life | ~30 minutes subcutaneous. |
| FDA status | Not FDA approved |