Metabolic

AOD-9604

Reviewed 22 October 2026 · How we research

Also known as: AOD9604, Tyr-hGH 177-191, Advanced Obesity Drug

What is AOD-9604?

AOD-9604 (“Advanced Obesity Drug”) is a 16-amino-acid peptide made from the tail end of human growth hormone — residues 177–191 with an extra tyrosine added at the start. The idea was to keep growth hormone's fat-burning (lipolytic) effect while dropping its effects on growth, blood sugar and IGF-1.

It looked promising in obese mice, but a large human trial did not show meaningful weight loss and its development as an obesity drug was dropped in 2007. It is still widely discussed in the peptide community, often alongside the closely related “HGH fragment 176-191”.

How AOD-9604 works

In rodent fat tissue, AOD-9604 stimulated lipolysis (fat breakdown) and inhibited lipogenesis (fat storage), apparently without binding the full growth-hormone receptor. Unlike full-length growth hormone it did not raise IGF-1 or impair insulin sensitivity in those studies. Later work suggested some effects may involve beta-3 adrenergic pathways, although results in β3-receptor knockout mice were mixed.

What the research shows

• Obese mice treated for 14 days lost body weight and fat with no change in food intake.
• Human phase 1 and early phase 2 studies found it well tolerated at oral doses.
• A 2007 phase 2b trial in around 500 adults with obesity did not achieve statistically significant weight loss versus placebo, ending its obesity programme.
• Later preclinical work explored cartilage repair, without human trial results.

AOD-9604 side effects

In the human safety studies AOD-9604 was well tolerated, with adverse-event rates similar to placebo and no change in IGF-1 or glucose handling. Those studies used controlled pharmaceutical-grade material; peptides bought online carry additional risks from purity, contamination and dosing errors.

UK legal status

AOD-9604 is not a licensed medicine in the UK and has no approved use. It is sold only as a research chemical. It is on the WADA Prohibited List, so tested athletes cannot use it.

More detail, including current UK research-vial prices: AOD-9604 UK guide. For the doses used in published studies and the reconstitution maths: AOD-9604 dosing in the literature.

References

1. Heffernan M, et al. The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following chronic treatment in obese mice and β3-AR knock-out mice. Endocrinology. 2001;142:5182–5189.
2. Ng FM, et al. Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone. Horm Res. 2000;53:274–278.
3. Stier H, et al. Safety and tolerability of the hexadecapeptide AOD9604 in humans. J Endocrinol Metab. 2013;3:7–15.