Compound research
AOD-9604: Research Overview & Current Status
AOD-9604 is a Growth hormone fragment peptide (hGH 176-191 modified fragment). Current research status: discontinued in clinical development. AOD-9604 completed six human clinical trials (over 900 participants) for obesity between 2001-2007 but development was discontinued in 2007 after a Phase IIb trial failed to show statistically significant weight loss versus placebo. It has never received FDA, EMA, or TGA approval for any indication, and in December 2024 the FDA determined AOD-9604 should not be included on the 503A Bulks List for compounding, citing limited long-term safety data and immunogenicity concerns.
Overview
AOD-9604 is a modified fragment of the C-terminal region (amino acids 176-191) of human growth hormone, engineered by Metabolic Pharmaceuticals Ltd. in Australia in the 1990s to isolate GH's lipolytic (fat-metabolizing) activity while removing its broader growth-promoting and metabolic effects.
Growth hormone fragment peptide (hGH 176-191 modified fragment)
Research timeline
1990s
AOD-9604 developed by Metabolic Pharmaceuticals Ltd. (Australia) as a modified hGH fragment isolating lipolytic activity.
Source →2001-2007
Metabolic Pharmaceuticals conducted six human clinical trials involving over 900 participants evaluating AOD-9604 for obesity management.
Source →circa 2005
Phase IIa trial (12 weeks, 300 participants) reported modest weight reduction of 2.6 kg versus 0.8 kg for placebo.
Source →2007
Phase IIb trial (24 weeks, 536 subjects) found no statistically significant weight-loss difference versus placebo, leading Metabolic Pharmaceuticals to terminate obesity-indication development.
Source →Post-2007
AOD-9604 was licensed for exploration in osteoarthritis research, pivoting away from the obesity indication.
Source →2024
FDA determined AOD-9604 should not be added to the 503A Bulks List for compounding pharmacies, citing limited long-term safety data, peptide impurities, and immunogenicity concerns.
Source →2026
As of April 2026, AOD-9604 is listed as 'Nominated but Withdrawn' from FDA Category 2 nomination status.
Source →
Active & recent research
AOD-9604 Phase IIb obesity trial (completed, negative result)
Weight-loss efficacy versus placebo over 24 weeks in 536 subjects; did not reach statistical significance
AOD-9604 in osteoarthritis research
Investigating a pivot indication after the obesity trial program was discontinued
Key findings
- A 12-week Phase IIa trial (300 participants) reported a modest but statistically distinguishable weight reduction (2.6 kg vs. 0.8 kg placebo), which supported advancement to Phase IIb.
- The subsequent 24-week Phase IIb trial (536 subjects) — the largest and most rigorous trial conducted — found no statistically significant difference in weight loss versus placebo, which led directly to program termination in 2007.
- Across all six completed trials (900+ participants), AOD-9604 was reported as well-tolerated with minimal adverse effects; the program failure was attributed to efficacy, not safety.
- The FDA's December 2024 determination against including AOD-9604 on the 503A Bulks List reflects ongoing regulatory concern about limited long-term human safety data even outside the original obesity indication.
Safety & regulatory notes
AOD-9604 is not FDA-approved for any indication. Its formal obesity development program was discontinued in 2007 due to lack of efficacy in the pivotal Phase IIb trial, not due to safety findings — the trials reported it as well-tolerated. However, in December 2024 the FDA declined to add AOD-9604 to the 503A Bulks List used by compounding pharmacies, citing limited long-term safety data, peptide impurity concerns, and potential immunogenicity, and its FDA Category 2 nomination was subsequently withdrawn.
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Where it's sold for research
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AOD-9604 FAQ
Is AOD-9604 FDA-approved for weight loss?+
No. AOD-9604 was never approved by the FDA, EMA, or TGA. Its obesity clinical development program was discontinued in 2007 after a Phase IIb trial failed to show statistically significant weight loss versus placebo.
Why was AOD-9604 development discontinued?+
Development ended for efficacy reasons, not safety: the pivotal Phase IIb trial (536 subjects, 24 weeks) found no statistically significant weight-loss benefit at the tested dose compared with placebo.
Was AOD-9604 considered safe in its trials?+
Across six completed trials with over 900 participants, AOD-9604 was reported as well-tolerated with minimal adverse effects; the program's failure was attributed specifically to lack of efficacy.
What is AOD-9604's current regulatory status?+
As of the FDA's December 2024 determination, AOD-9604 is not included on the 503A Bulks List for pharmaceutical compounding, and its FDA Category 2 nomination has been withdrawn, reflecting ongoing regulatory caution about limited long-term safety data.
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