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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 · HGH Frag 176-191 · Frag 176-191 · Fragment 176-191

(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 missed its primary weight-loss endpoint in a pivotal Phase 2b; (2) its safety was actually good (no IGF-1/glucose problems) — the failure was efficacy, which is the more damning kind; (3) it's still sold everywhere for fat loss, making the honest "it flunked its own pivotal trial" the single most useful thing a reference can say.

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

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

How we grade →

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

—

Disclosure

Vallydia sells its own cosmetic serums, and some ingredients graded here belong to the same categories as those products. Grades are drawn from the published evidence by the method we publish, and applied to our own ingredients on the same terms — our copper-peptide serum is graded no more kindly than the peptides it competes with. We disclose the interest so you can weigh it.

Trade names shown here (for example Matrixyl, Argireline, Syn-Ake) are the property of their respective owners and are used only to identify the ingredient under discussion. Their appearance implies no affiliation with, or endorsement by, the proprietor.

Evidence changes

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We track new research and update these grades as the evidence moves. Leave your email and we'll tell you if the evidence for AOD-9604 (hGH fragment 176-191 analog) changes - nothing else.

Not the same as its namesake

The bare growth-hormone fragment 176-191 ("Frag 176-191") is NOT equivalent to AOD-9604. AOD-9604 is a MODIFIED analog of that fragment - stabilised with an added N-terminal tyrosine and a disulfide bridge - not the unmodified peptide. Searches for the bare fragment resolve to this entry for reference, but the register does not treat them as the same molecule: AOD-9604's clinical record (including its failed pivotal Phase 2b) was generated on the modified analog and does not transfer to the unmodified fragment.

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.

Chemical identifiers

Cross-reference identifiers for the authoritative external databases — not a recipe, and nothing about how to use it.

PubChem CID71300630

InChIKeyGVIYUKXRXPXMQM-BPXGDYAESA-N

SMILESCC[C@H](C)[C@@H](C(=O)N[C@@H](C(C)C)C(=O)N[C@@H](CCC(=O)N)C(=O)N[C@H]1CSSC[C@H](NC(=O)[C@@H](NC(=O)CNC(=O)[C@@H](NC(=O)[C@@H](NC(=O)[C@@H](NC(=O)[C@@H](NC1=O)CCCNC(=N)N)CO)C(C)C)CCC(=O)O)CO)C(=O)NCC(=O)N[C@@H](CC2=CC=CC=C2)C(=O)O)NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CC3=CC=C(C=C3)O)N

via PubChem exact-name match (AOD-9604) · high confidence

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).

Updated 2026-07-13 (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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This site provides neutral scientific reference and sells only products lawful in your region. Nothing here is medical advice, a recommendation, or an offer to supply unapproved medicines. No dosing or administration is published for research compounds. Cosmetic peptides per Regulation (EC) 1223/2009. Unapproved injectable peptides are neither sold nor advertised in the EU (Directive 2001/83/EC, Title VIII). © 2026 Vallydia.