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Explore  /  AOD-9604 (hGH fragment 176-191 analog)
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AOD-9604 (hGH fragment 176-191 analog)

F
lead outcome
Weight loss / obesity (the intended use)
grades vary by outcome ↓
Peptide⚠ WADA-banned
also called — AOD-9604 · "Anti-Obesity Drug 9604" · CJC-tyrosine-fragment. INCI: none
(intended:) fat loss / lipolysis(failed:) obesity/weight-loss drug(gray-market:) joint/recovery

The register's cleanest honest-debunk: a fat-loss peptide that was properly tested in humans — and failed. Three points define this entry: (1) unlike most gray-market compounds (F because untested), AOD-9604 is F because it was tested and didn't work — it ran six human trials in 900+ people and miss

In brief

AOD-9604 is a synthetic fragment of growth hormone's fat-burning tail (residues 176-191, stabilised with a tyrosine and a disulfide bridge), engineered by Metabolic Pharmaceuticals in the 1990s to isolate GH's lipolytic effect without its growth/IGF-1/glucose effects. On the design goal it succeeded — it doesn't raise IGF-1 or disturb blood sugar, and its safety across six trials in 900+ people was reassuring. But on the thing that matters, it failed: a pivotal Phase 2b trial in 500+ obese adults missed its primary weight-loss endpoint, the effect was too small to be clinically meaningful, and Metabolic Pharmaceuticals abandoned it in 2007. This is the register's clearest example of an honest debunk — not "unproven because nobody studied it," but "studied properly and it didn't work." It's still sold everywhere for fat loss; the single most useful fact a reference can carry is that it flunked its own pivotal trial. It's also not FDA-approved, FDA-flagged as a risk-bearing bulk substance, and WADA-banned in sport.

Legal standing, by region
European Union
Not FDA-approved (gray-market)

not approved; investigational/research chemical; not a cosmetic.

United States · your region
Not approved

not FDA-approved for any use; listed by the FDA as a bulk drug substance that may present safety risks (i.e. flagged, not endorsed).

⚠ WADA-prohibited in sportSport WADA-prohibited: growth-hormone fragments including AOD-9604 / hGH 176-191 are on the banned list. Detectable; sanctionable regardless of intent.
Evidence, by outcome

An honest grade per outcome — drawn from the evidence, not any catalogue. Hype and undemonstrated marketing claims grade low.

OutcomeEvidence base · effectGrade
Weight loss / obesity (the intended use)
The strongest kind of "F" — tested in a proper trial and failed. Not a data gap; a negative result
Pivotal Phase 2b (~500+ obese adults, 12 wk, placebo-controlled): did NOT meet primary endpoint; effect modest, not clinically meaningful → development abandoned 2007
F
Lipolysis / fat metabolism (mechanistic)
Real in the lab / animals — but the lab effect did not translate into human weight loss (that's the whole lesson)
Animal + in-vitro: stimulates fat breakdown, inhibits lipogenesis (receptor-independent)
D
IGF-1 / glucose neutrality (the design goal)
Here the molecule genuinely delivered — it is metabolically clean; unfortunately "clean but ineffective" doesn't make a drug
Human trials: no IGF-1 elevation, no glucose disturbance
B
Joint / osteoarthritis (repurposing)
Not established; a second unproven indication
Explored post-obesity; some interest
F
Safety / tolerability
Well-characterised, well-tolerated (this is genuinely its strong suit) — but safety without efficacy isn't a therapy; and it's FDA-flagged as a bulk substance + WADA-banned
6 trials, 900+ participants

Identity a synthetic 16-amino-acid peptide based on the C-terminal region of human growth hormone (residues ~176/177-191) with two engineering tweaks: a tyrosine added at the N-terminus and a disulfide bridge (cyclisation) that makes it far more resistant to enzymatic breakdown in plasma (better stability/bioavailability than the raw fragment). The design hypothesis: isolate GH's fat-burning (lipolytic) action while leaving out its growth-promoting, IGF-1-raising and diabetogenic effects. ## Mechanism (as proposed) AOD-9604 corresponds to the C-terminal lipolytic domain of hGH. In preclinical models it stimulates lipolysis (fat breakdown) and inhibits lipogenesis (new fat formation) — but, crucially, it does not bind/activate the classical growth-hormone receptor, so it produces these fat effects without the IGF-1 rise, insulin resistance, or tissue-growth signals of full-length GH. Mechanistically that's an appealing "clean lipolysis" story — and it's real in animals. The problem is purely translational: the isolated lipolytic effect, genuine in the lab, simply wasn't powerful enough to drive meaningful weight loss in humans at the doses tested. Elegant mechanism, clean safety, negative pivotal trial.

Sources — 5 cited
01Ng FM, Heffernan M, et al. — C-terminal hGH fragment lipolysis work (Monash / Metabolic Pharmaceuticals); Effects of a synthetic hGH fragment on lipid metabolism. Am J Physiol Endocrinol Metab. 2000 (PMID 10950816).
02Phase 2b obesity trial (Metabolic Pharmaceuticals, ~500+ adults) — primary endpoint not met; development discontinued ~2007 (reported across the clinical-review literature).
03FDA — AOD-9604 listed among bulk drug substances flagged for potential safety risks (not compoundable/approved).
04WADA 2026 Prohibited List — growth-hormone fragments incl. AOD-9604 / hGH 176-191.
05Safety database: six controlled trials, 900+ participants (well-tolerated; no IGF-1/glucose signal).
Review status
Not yet reviewed

A credentialed reviewer (PharmD / PhD / MD) will be named before this entry is finalised. Until then, treat it as a working draft. Last updated July 2026 (status stable — a failed/abandoned obesity program; unlikely to change absent a new indication with real data).

Grades reflect the published evidence, not our interest. No dosing, reconstitution, or administration is published for research compounds — that restraint is deliberate.

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AOD-9604 — the fat-loss peptide that failed its human trial: the honest evidence · Vallydia