The Pep Test Guide 2026
The Pep Test Guide 2026U.S. vendor guide
All compounds
Anti-aging

AOD-9604

Also known as: HGH fragment 176-191

HGH fragment without growth-promoting effect. Preclinical with indications of fat oxidation.

AOD-9604

What is AOD-9604

AOD-9604 is a synthetic fragment of human growth hormone (hGH). More precisely: It corresponds to the amino acids 176-191 at the C-terminus of hGH, plus an additional tyrosine residue at the N-terminus for stabilization. The complete hGH molecule has 191 amino acids, so AOD-9604 is only a small section with 16 amino acids.

The name AOD stands for "Anti-Obesity Drug". The molecule was identified at the Howard Florey Institute in Australia in the 1990s from Frank Ng. Metabolic Pharmaceuticals licensed the program and conducted phase 2 clinical trials for obesity. Admission was never achieved.

CAS No: 221231-10-3. Molecular weight: 1815.1 g/mol. Sequence: Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe.

Mechanism of action

The idea behind AOD-9604 was to isolate the fat-burning effects of hGH without taking along the anabolic effects (muscle building, IGF-1 increase) and the adverse effects (insulin resistance, water retention, GH-related hypertrophies).

In animal studies, the C-terminal fragment showed a direct lipolytic effect on adipocytes, presumably via beta-3 adrenergic mechanisms, without IGF-1 or other classical GH effects being mediated. This theoretical "clean" fat burning without the shadows from full hGH made AOD-9604 an interesting anti-obesity candidate substance.

In human studies, however, this selectivity was not as clearly reproducible as in animal models. The effects on body weight were significantly weaker than expected in the completed phase 2 studies.

Areas of application in research

  • Obesity: Main indication in original development, clinically disappointing
  • Bone and joint healing: Later studies on osteoarthritis
  • Sports injuries: Off-label application in the self-application community
  • Lipolysis support: In combination with diet and training

Study situation

The database on humans is thinner than often assumed.

Important works:

  • Ng et al. (Hormone Research, 2000): Early preclinical characterisation
  • Metabolic Pharmaceuticals Phase 2 trials: 12-week study in obese subjects, marginal weight reduction with no significant advantage over placebo
  • Heffernan et al. (Journal of Endocrinology, 2001): Lipolytic action in vitro and in animals
  • Kim et al. (Osteoarthritis and Cartilage, 2010): Effect on chondrocytes in osteoarthritis models

What is clear: In animals, the HGH fragment exhibits lipolytic properties. What remains unclear: whether this effect on humans is clinically relevant. The completed phase 2 studies were the primary reason for the development stop.

GTAC (Gene Therapy Advisory Committee) and Therapeutic Goods Administration (TGA) in Australia have classified AOD-9604 as "generally recognized as safe" (GRAS) in 2014, but this is not synonymous with clinical efficacy.

Mixing (reconstitution)

Typical Vial sizes: 2 mg, 5 mg lyophilisate.

  • 5-mg Vial with 2 ml of bacteriostatic water → 2.5 mg/ml (corresponds to 250 mcg per 0.1 ml)
  • 5-mg Vial with 5 ml → 1 mg/ml for smaller doses

After mixing cooling 2 to 8 degrees, stability about 4 to 6 weeks. Lyophilisateeeee stable at -20 degrees over years.

Dosage range (research data)

In Phase 2 studies:

  • 1 mg per day, subcutaneous
  • Has also been tested in higher doses without clear added value

In the research use community:

  • 300 to 500 mcg per day, subcutaneous
  • Frequency: once a day, ideally sober in the morning
  • Cycle duration: 4 to 12 weeks

These values are research references, not clinically validated.

Side effects

In the Phase 2 studies, the tolerability profile was favorable:

  • Local irritation at the injection site
  • Rare headaches
  • Rare nausea
  • No GH-typical side effects (no IGF-1 increase, no insulin resistance, no water retention)

Compared to full hGH, AOD-9604 is significantly better tolerated. The price of this tolerability is the weaker clinical effect.

Theoretical long-term risks are unclear because there are no sufficiently long studies.

Half-Life and Pharmacokinetics

Elimination half-life: about 30 minutes to 1 hour. Bioavailability subcutaneously high. Maximum plasma level after about 30 minutes.

metabolism via peptidic degradation processes. No relevant CYP interactions. excretion renal as fragments.

Oral bioavailability is limited but higher than many other peptides, leading to trials of Oral formulations.

Frequent questions

Does AOD-9604 work for weight loss? In clinical trials, weight loss was marginal and not superior to placebo. In self-application, users report subjective effects, but this is not scientifically reliable.

Is AOD-9604 the same as hGH? No. It is only a small fragment (amino acids 176-191) and does not have the anabolic effect of full growth hormone. It does not increase IGF-1 relevant.

Does AOD-9604 have doping relevance? WADA explicitly does not have AOD-9604 on the prohibited list because it does not show GH-typical anabolic effects. Status can change when applying competition check current list.

Can AOD-9604 be used Orally? There are research use vendors with Oral formulations. However, Oral bioavailability is limited and clinically unestablished.

How is AOD-9604 different from GLP-1 agonists? Completely different mechanism. GLP-1 agonists (semaglutide, tirzepatide) act via appetite inhibition and gastric emptying. AOD-9604 theoretically acts directly on fat cells. The GLP-1 class has shown dramatically stronger clinical effects.

Legal status U.S.

As of 2026: AOD-9604 does not have a pharmaceutical license in Germany, Austria and Switzerland. Sales in the research-use-only rail.

In Australia, AOD-9604 is available as a dietary supplement ingredient in some products, but this does not apply to the EU market.

WADA status: not on the prohibited list (as of 2026).

Self-import: §73 AMG restrictions on therapeutic intention.

Related compounds

  • hGH (somatotropin)Complete growth hormone
  • tesamorelineAuthorised GHRH analogue for HIV lipodystrophy
  • ipamoreline/CJC-1295: Stimulate the body's own GH release
  • MK-677Oral ghrelin mimetic, increased GH/IGF-1
  • semaglutidee / tirzepatideeGLP-1 agonists for weight reduction

Note: All information is for research information only. These peptides are not approved as medicines in Germany. The contents do not replace medical advice. Application to humans is not legally covered in Germany.