AOD-9604

What is AOD-9604?

AOD-9604 (Anti-Obesity Drug 9604) is a synthetic peptide made up of 16 amino acids. It is a modified fragment of human growth hormone (hGH 177-191), designed to specifically stimulate fat breakdown without triggering the unwanted side effects of the full growth hormone, such as an increase in IGF-1, tissue growth, or blood sugar fluctuations. The peptide has a molecular weight of 1,817 Daltons and was originally developed by Metabolic Pharmaceuticals as a drug to treat obesity.

Structurally, AOD-9604 corresponds to the amino acid sequence Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe. The key difference from the natural hGH fragment 177-191 lies in the modification at the N-terminus (the start of the chain): AOD-9604 carries a tyrosine there instead of a phenylalanine. This targeted swap was intended to isolate the lipolytic (fat-burning) effect of growth hormone and separate it from systemic side effects.

Functionally, you can think of the peptide as a selective tool: while the full growth hormone simultaneously affects muscle growth, bone density, glucose metabolism, and fat burning, AOD-9604 was designed to activate fat burning in isolation. The other metabolic pathways should remain untouched, which is the theoretical basis of the substance.

How is AOD-9604 used?

In clinical studies, AOD-9604 was given both orally (in capsule or tablet form at 0.25-1 mg per day) and subcutaneously (as an injection under the skin at 200-300 µg per day). Outside of clinical trials, users almost exclusively use the subcutaneous injection at 200-500 µg per dose, split into several doses throughout the day. Oral forms from the earlier studies are no longer in circulation.

A key pharmacokinetic property is the short half-life of about 15-20 minutes: the active substance is rapidly metabolized in the body. A single daily dose is therefore considered barely effective, which is why user protocols spread 2-3 individual doses across the day. In studies, injections were mostly given into the subcutaneous fat fold on the abdomen or thigh, matching the guide to injection sites.

The study duration in human trials was up to 24 weeks, while experience reports often mention cycles of 4-6 weeks. Since AOD-9604 was never approved as a drug, there are no official medical dosage recommendations; all reports outside the studies are purely user practice.

How does AOD-9604 work?

AOD-9604 differs fundamentally from the full growth hormone in its mechanism of action: it does not bind to the classic GH receptor and therefore does not cause a clinically relevant increase in IGF-1. Its effect is primarily based on activating hormone-sensitive lipase (HSL) in the adipocytes (fat cells) and on interacting with the beta-3-adrenoceptor signaling pathway, through which the body's own adrenaline also releases fatty acids.

At the cellular level, AOD-9604 targets two effects: increasing lipolysis (the release of stored fats) and simultaneously inhibiting lipogenesis (the formation of new fat tissue). In-vitro studies on isolated human fat tissue confirmed increased lipolytic activity. In animal models with obese mice and rats, the peptide significantly reduced body weight and fat mass. Since this effect also occurred in beta-3-knockout mice without a functional beta-3 receptor, the involvement of other signaling pathways such as the MEK-ERK pathway is being discussed.

The theoretical benefit was to stimulate fat burning without an IGF-1 increase, cell proliferation, or impaired insulin sensitivity. Although this mechanism could be reproduced in the test tube and in animal models, confirmation in large-scale clinical human trials failed.

How effective is AOD-9604?

The effectiveness of AOD-9604 for weight loss in humans is not scientifically proven: while preclinical in vitro and animal models showed positive effects on fat burning, the pivotal Phase 2b OPTIONS study with over 500 obese participants missed its primary efficacy endpoint. There was no statistically significant weight loss compared to placebo, and the development program was discontinued in 2007.

Decisive for the evaluation of the OPTIONS study was its design: all over 500 participants followed a controlled diet and exercise program alongside the treatment. Even under these test conditions, which are optimal for weight loss, AOD-9604 showed no measurable benefit over placebo. Combining the peptide with exercise and a calorie-reduced diet brings no proven added value according to the scientific data.

While early Phase 2a studies with around 300 participants hinted at weak trends of moderate weight loss, these results could not be reproduced in the methodologically stricter Phase 2b. Such discrepancies between early pilot data and large confirmatory studies are a common phenomenon in pharmaceutical drug research.

The AOD-9604 study program

The clinical study program for AOD-9604 included six studies between 2001 and 2007 with a total of over 900 participants at doses from 0.25 mg to 54 mg. The range went from intravenous and oral tolerance tests to a Phase 2a study with around 300 participants and the Phase 2b OPTIONS study with more than 500 participants.

Clinical testing began with safety and tolerability studies of intravenous and oral administration. After Phase 2a with around 300 participants provided preliminary signals of weight reduction, the Phase 2b OPTIONS study started as the decisive efficacy test of the entire program.

OPTIONS was designed as a randomized, placebo-controlled double-blind study. The over 500 obese participants received oral AOD-9604 at different dose levels combined with a standardized lifestyle intervention. A significant difference from the placebo group did not emerge, which is why Metabolic Pharmaceuticals officially discontinued the obesity program in March 2007; the company subsequently filed for bankruptcy.

What remained as a usable result of the six studies was an extensive safety database: in over 900 participants, AOD-9604 showed consistently high tolerability, which explains the continued interest in experimental user circles.

Dosage: what the studies show - and the reality

In human studies, AOD-9604 was tested subcutaneously at doses of 200-300 µg per day and orally at 0.25-1 mg per day over periods of up to 24 weeks. Since no regulatory approval was granted, there are no validated medical intake guidelines. The short half-life of 15-20 minutes leads to daily amounts being divided into several individual doses in community practice.

In user communities, injection doses of 200-500 µg per administration are often described, given several times a day. These figures are based on purely subjective experience reports and do not constitute a medical dosage recommendation. The very short half-life of 15-20 minutes means that a single daily dose is likely to be ineffective, as the active substance is already completely broken down after a few minutes.

From vial to use: mixing and dosing AOD-9604

AOD-9604 is usually supplied as a freeze-dried (lyophilized) powder and is reconstituted with sterile BAC water for subcutaneous injection. The calculation follows a simple scheme: the amount of solvent divided by the amount of peptide determines the concentration, from which the injection volume for the desired dose is derived. A detailed guide to reconstitution and storage is provided in the peptide guides.

Example calculation: If a vial contains 2 mg of AOD-9604 powder and is dissolved with 2 ml of BAC water, the active substance concentration is 1 mg/ml (1,000 µg/ml). For a single dose of 250 µg (0.25 mg), you need 0.25 ml of solution. With a standard U-100 insulin syringe with a total volume of 1 ml, this corresponds to a marking of 25 units (IU).

Given the short half-life of 15-20 minutes, administration is usually spread over several subcutaneous doses into the fat tissue of the abdomen or thigh. Since AOD-9604 is not an approved drug, products from the internet are not subject to any pharmaceutical purity control; information on active substance content and sterility is often unverified. Criteria for identifying counterfeits are explained in the protection and vendor radar.

Side effects and common mistakes

In the six clinical studies with over 900 participants, AOD-9604 proved to be well tolerated: the side effect profile was at the level of placebo, with no serious adverse events, IGF-1 increases, or impaired glucose tolerance. Documented mild side effects were limited to local skin reactions such as redness or itching at the injection site, mild headaches, and occasional gastrointestinal complaints such as nausea.

This safety profile explains the continued popularity in the biohacking scene despite the lack of proven efficacy. The peptide does not affect IGF-1 levels or insulin sensitivity. However, good tolerability does not compensate for the lack of the desired pharmacological effect.

• Wrong expectations about weight loss: The clinical evidence in humans is insufficient - the Phase 2b study missed its endpoint, even with diet and exercise.
• Ignoring the half-life: AOD-9604 is broken down in 15-20 minutes; a single daily dose is likely ineffective, so splitting into several doses is necessary.
• Black market purchases without quality control: Buying online carries unpredictable risks regarding purity, sterility, and dose consistency.
• Use in sport: AOD-9604 is on the WADA doping list and leads to positive doping tests.
• Lack of medical supervision: Since there is no approval, there are no medically validated protocols or follow-up examinations.

Approval and legal status

AOD-9604 is not approved as a drug by any regulatory authority worldwide - neither by the FDA in the US, nor by the EMA in the EU, nor by the BfArM in Germany. The World Anti-Doping Agency (WADA) explicitly lists the substance in the category of growth hormone fragments, which means its use in competitive sport is strictly prohibited.

Legally, AOD-9604 may not be prescribed as a medication or sold through public pharmacies in Germany and the European Union. Online shops often advertise the peptide as a "dietary supplement" or "research chemical," which obscures the actual legal gray area. Athletes must be aware that a positive test for AOD-9604 constitutes a violation of anti-doping regulations and can lead to disciplinary bans.

Additional risks arise from unregulated sources: since no GMP standards are controlled for unapproved peptides, purity, contamination, and actual dosage remain uncertain. The tolerability documented in clinical studies applies only to pharmaceutically tested investigational products and cannot be transferred to freely traded products. For more in-depth substance profiles, see the peptide library.