Evidence memo / GH / IGF axis

AOD-9604

Also: HGH Frag 176-191 · hGH fragment 176-191 · Tyr-hGH 177-191 · AOD9604 · LAT8881 identity context · modified C-terminal hGH fragment

A modified growth-hormone-fragment peptide with sparse historical obesity-development evidence, stronger product-identity and compounding-safety concerns, and no established modern obesity or body-composition use.

Claim-specific / contestedSafety/regulatory watchSafety / regulatory watch

The verdict

Our read at a glance.

Whether historical AOD-9604 obesity-development evidence and growth-hormone-fragment biology support current weight-management, body-composition, or wellness claims.

The signal
FDA's 2024 PCAC briefing evaluated AOD-9604 free base and AOD-9604 acetate in the 503A bulk-substance context and states that the larger historical OPTIONS obesity study did not show a significant primary-endpoint weight-loss difference versus placebo. ANZCTR documents the OPTIONS trial registration, but this source set does not cite posted trial results.
The unknown
Whether any well-characterized AOD-9604 product has clinically meaningful modern obesity or body-composition outcome evidence, and how current compounded, research-use, or internet-market products relate to studied material.
Our read
A safety/regulatory watch because the public claim space is much larger than the direct human evidence. AOD-9604 free base/acetate, LAT8881 non-obesity registry contexts, AOD9401, native hGH fragments, full hGH, compounded products, research-use products, and internet-market products are separate evidence categories and should not be treated as equivalent.

The mechanism

How it works.

AOD-9604 is a synthetic peptide copying the tail end (the C-terminal region) of human growth hormone, the part linked to fat metabolism rather than growth. The idea is that this fragment triggers fat cells to break down stored fat and burn it, without the blood-sugar and IGF-1 effects of the full growth-hormone molecule. The fat-burning mechanism comes mainly from animal and cell work, and a larger human obesity trial did not beat placebo, so it has not been shown to drive meaningful fat loss in people.

Safety & regulatory boundary

The consequential part.

FDA lists AOD-9604 among nominated-but-withdrawn bulk substances that may present significant safety risks and identified potential immunogenicity, peptide impurity/API characterization issues, limited safety information, and unclear causality for serious adverse events. This is not an FDA approval document or a global legal-status conclusion.

What's next

What we're watching.

FDA compounding-status updates, independent peer-reviewed clinical outcomes, product characterization standards, and clearer safety reporting. Date-limited checks found no direct AOD-9604 obesity record in ClinicalTrials.gov; LAT8881 registry records are non-obesity contexts and are not treated as public evidence for this memo.

Context

Why this is discussed.

It is often promoted with a simple growth-hormone-fragment weight-control story, while the public evidence base is mostly older development context, regulatory review, identity records, and nonhuman or analytical literature.

The evidence base

31 cited references.

Regulatory & labels6

FDA briefing document: AOD-9604-related bulk drug substances

U.S. Food and Drug Administration · 2024-11-05

FDA PCAC slide deck: AOD-9604 human safety study

U.S. Food and Drug Administration · 2024-12-04

WADA statement on substance AOD-9604

World Anti-Doping Agency · 2013-04-22

The 2026 prohibited list

World Anti-Doping Agency · Effective 2026-01-01

Indexed literature (PubMed)18

AOD-9604 metabolic

Wilding · 2004

Sponsor & other sources4

ANZCTR: the effect of AOD9604 on weight loss in obese adults / OPTIONS Study

Australian New Zealand Clinical Trials Registry · Registered 2005; last updated 2007

PubChem: AOD-9604

National Library of Medicine · Record modified 2025

GSRS: UNII 7UP768IP4M / LAT-8881

FDA / NIH NCATS · Current database page

NCATS Inxight Drugs: LAT-8881 / AOD-9604

NIH / NCATS · Current database page

Keep reading

Related published memos.