Also called Anti-Obesity Drug 9604, hGH fragment 177-191 (modified), Tyr-hGH 177-191
A piece of growth hormone meant to burn fat that failed its biggest human trial.
AOD-9604 is a short peptide (16 amino acids) made from the tail end of human growth hormone, pieces 177 to 191, plus one extra amino acid. It was developed in Australia in the 1990s and 2000s as an anti-obesity pill. The goal was to keep growth hormone's fat-burning effect without its effects on growth, blood sugar or IGF-1 (a growth signal made by the liver).
In rats and mice, it made fat cells burn stored fat faster and make less new fat. Unlike full growth hormone, it didn't raise IGF-1 or hurt blood sugar control in those animals. Whether it does much to fat in people is the open question.
Some human studies
The evidence is weak. Rodent studies from 2000–2001 showed fat loss, but the developer's largest human trial, a 24-week study in about 500 people reported in 2007, didn't beat placebo, and those results were never published in a peer-reviewed journal. Short human studies looked safe enough, but people now mostly inject it at doses that were never tested.
Why: It's thought to leave the body fast, so people take it daily. Taking it on an empty stomach is meant to avoid the insulin bump from food, which blocks fat burning. None of this has been tested in trials.
Start at the low end, and change one thing at a time. If you take medication or have a health condition, check with a doctor first.
Set up for a 2 mg vial. Change any number to match yours. New to this? Read how to mix a vial and mg vs mL vs units first.
Pick your dose and how long you'll run it. We'll count what you need.
Get help right away for swelling of the face or throat, trouble breathing, chest pain, or a spreading, hot, red injection site.
Powder: fridge or freezer. Once mixed: fridge, use within about 4 weeks.
FDA: Not approved as a drug. In 2024 the FDA proposed keeping it off the list of substances pharmacies may compound, citing immune-reaction and impurity concerns.
Sport (WADA): Prohibited at all times. WADA has stated it falls under S0 (non-approved substances); it is also named as a growth hormone fragment under S2.
No. It's a small piece of growth hormone. It doesn't raise IGF-1 and doesn't have growth hormone's effects on muscle or growth.
The animal results looked good, but the biggest human trial didn't beat placebo. Any fat loss people notice is hard to separate from diet and exercise.
Almost. They're nearly identical pieces of growth hormone sold under different names, and both lack strong human evidence.
Last checked 2026-10