A small piece of the growth-hormone molecule designed to encourage fat burning without raising growth-hormone levels.
Fat loss, especially when growth-hormone–based options aren't a good fit.
Its large human weight-loss trial didn't beat a placebo, so today's use goes beyond what was actually proven.
What it is
AOD-9604 is a small fragment taken from the end of the growth hormone molecule — specifically, the portion researchers believed was responsible for stimulating fat breakdown. The idea behind isolating it was smart: if you can capture the fat-burning effect without triggering growth hormone release, you avoid the insulin resistance and IGF-1 elevation that come with GH-axis peptides. And that part worked — AOD-9604 does not raise IGF-1, which makes it genuinely useful in situations where growth hormone pathway concerns exist. What didn't work was the larger goal: when put through Phase 2b/3 human trials as a weight loss drug, it didn't outperform placebo in statistical terms, which is why the pharmaceutical program was discontinued. The GRAS designation sometimes cited for it applies only to food-additive amounts, not injectable therapeutic doses.
Potential benefits
Fat Breakdown (Lipolysis)
Animal data and early-phase human trials showed fat metabolism effects. Large-scale weight loss vs. placebo was not statistically significant in Phase 3.
No IGF-1 Elevation
Does not raise IGF-1 — meaningful distinction from GH-axis peptides and the primary reason it's preferred for fat-loss in cancer-risk or metabolic patients.
Cartilage & Joint Repair
Emerging animal and early human data. Often combined with BPC-157. Evidence is early-stage.
Metabolic Effects
Some data suggests modest effects on metabolic rate and fat oxidation. Not established in large human trials.
Risks and contraindications
Side Effects
- Headache, nausea (reported in clinical trials)
- Injection site irritation
- Chest tightness — small number of early trial participants
- Compound quality risk — unregulated sourcing
Theoretical Risks
- Long-term GH fragment receptor effects unknown
- Combination peptide stacking risks not studied
- Drug interactions with GLP-1 agonists, insulin not characterized
Contraindications / cautions
- Active malignancy · Pregnancy · Breastfeeding
- Under 18 · Known hypersensitivity to GH-derived compounds
- On GLP-1 agonists or insulin (caution — interaction risk)
- Family history hormone-sensitive cancers (caution)
Research reality
Animal studies showed real fat reduction and metabolic improvement — compelling enough that the compound advanced to full human trials, which is a higher bar than most peptides in this space ever reach.
Phase 1, 2, and 2b/3 trials were completed for obesity treatment. Early-phase safety looked favorable. The larger definitive trial did not show statistically significant weight loss compared to placebo, which is why it was discontinued as a pharmaceutical development program.
The short-term safety data from clinical trials is more complete and reassuring than most peptides in this guide. Long-term safety for ongoing use — which is how it tends to be used in functional medicine today — doesn't exist from rigorous human trials.
One of the cleaner short-term safety profiles in the peptide space, with real clinical trial history. The Phase 3 failure matters — current body composition use extrapolates beyond what those trials studied. No IGF-1 elevation makes it a reasonable option where GH-axis concerns apply.