AOD-9604, what the science actually shows

AOD-9604 is a modified fragment of the C-terminus of human growth hormone (hGH) studied for fat metabolism. Not FDA-approved. Evidence base: reached Phase IIb human trials but failed to demonstrate weight loss; limited efficacy data.

A modified fragment of human growth hormone (amino acids 177-191) researched for fat metabolism. The Phase IIb oral trial did not meet its primary endpoint. The mechanism data still tells an interesting story.

Evidence
★★☆☆☆ Limited
Type
GH Fragment
Structure
16 amino acids

What AOD-9604 is

AOD-9604 is a synthetic peptide corresponding to the C-terminal fragment (amino acids 177-191) of human growth hormone, with an added tyrosine residue. Developed by Metabolic Pharmaceuticals in Australia to isolate the fat-metabolizing properties of growth hormone without growth-promoting or diabetogenic effects. 'AOD' stands for Anti-Obesity Drug.

Mechanism, in plain English

AOD-9604 mimics the lipolytic region of growth hormone. It stimulates the beta-3 adrenergic receptor pathway in fat tissue, increasing the release of stored fatty acids. Unlike full-length hGH, it does not compete for the GH receptor or raise IGF-1 levels. In animal models, it reduced body fat without affecting lean mass, blood sugar, or tissue growth. The mechanism is receptor-selective.

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What the evidence shows

Preclinical data showed significant fat reduction in obese mice and rats without changing food intake. A Phase IIb human trial (oral formulation) in obese adults ran for 24 weeks but did not achieve statistically significant weight loss versus placebo. The injectable form showed more promising earlier data. AOD-9604 was granted GRAS status by the FDA in 2014 as a food ingredient, distinct from drug approval.

FDA status

Not FDA-approved as a drug. GRAS status as a food ingredient (2014). WADA-prohibited in sport.

Common synonyms

AOD-9604, hGH fragment 177-191, Anti-Obesity Drug 9604, Tyr-hGH(177-191)

Safety and adverse-event landscape

Animal studies and Phase I/II trials reported no serious adverse events. The GRAS determination supports a favorable safety profile at food-ingredient doses. Long-term human safety data at therapeutic doses is limited.

Frequently asked questions

No. It was granted GRAS status in 2014 as a food ingredient, which is a different regulatory pathway from drug approval.
The trial used an oral formulation. Peptides generally have poor oral bioavailability. The injectable form showed more promise.
No. Unlike full-length growth hormone, AOD-9604 does not bind the GH receptor and does not increase IGF-1.
No. Peptexa is educational only.

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