Peptides — Established

AOD-9604 (HGH Fragment 176–191)

AOD-9604 is a fragment of human growth hormone (amino acids 176–191) that retains fat-burning lipolytic effects without stimulating IGF-1 or insulin. The "diet peptide" evidence reviewed.

Evidence: Preclinical + Phase II Trials Admin: Subcutaneous Injection Key: No IGF-1 Stimulation
Important Disclaimer

Research peptides are not approved for human use in most countries including India. This page is for educational purposes only. Consult a physician before use.

What is AOD-9604?

AOD-9604 (Anti-Obesity Drug 9604) is a synthetic peptide corresponding to amino acids 176–191 of the C-terminal region of human growth hormone (HGH), with a tyrosine at the N-terminus added for stability. This specific region of HGH is the portion responsible for lipolytic (fat-breaking) activity.

The rationale for isolating this fragment is elegant: full HGH stimulates growth and IGF-1 production throughout the body, including effects that increase insulin resistance and theoretical risk of cell proliferation. If only the fat-metabolizing activity could be isolated in a fragment, you would get the weight management benefit without the metabolic and safety concerns of full HGH.

AOD-9604 was developed by Metabolic Pharmaceuticals (an Australian company) specifically as an anti-obesity drug, and was the first peptide to complete Phase II clinical trials focused on fat loss.

Why No IGF-1 Stimulation Matters

Full human growth hormone works through two parallel mechanisms:

  1. Direct receptor binding: GH receptor activation → lipolysis, glucose effects, direct tissue effects
  2. IGF-1 induction: Liver produces IGF-1 in response to GH → anabolic effects, cell proliferation, insulin sensitization/resistance

AOD-9604 activates lipolysis through the beta-3 adrenergic receptor pathway, bypassing the GH receptor entirely. This means:

Clinical Trial History

AOD-9604 progressed through Phase II clinical trials for obesity under Metabolic Pharmaceuticals:

Honest Comparison

AOD-9604 should not be compared favorably to GLP-1 agonists for fat loss. Semaglutide (Wegovy) produces 15–17% body weight reduction. AOD-9604's Phase II results were modest and inconsistent — in the range of 1–2 kg over several months. Different league entirely.

Cartilage Research: A Different Direction

AOD-9604 has shown more consistent promise in a completely different area — cartilage and osteoarthritis:

AOD-9604 vs GLP-1 Drugs

Feature AOD-9604 Semaglutide (Wegovy)
Mechanism Beta-3 adrenergic activation (cellular metabolic shift) GLP-1 receptor agonism (CNS appetite suppression)
Average weight loss Modest, inconsistent (1–3 kg in trials) 15–17% body weight in Phase III trials
IGF-1 effect None None
FDA status GRAS (safe), not approved as drug FDA approved for obesity
Phase III trials Not completed for obesity Completed — highly effective
Additional benefits Cartilage repair (Phase II) Cardiovascular protection, T2DM

Dosing (Circulating Protocols)

Common protocols used in research and biohacking communities — not validated clinical dosing:

Frequently Asked Questions

Does AOD-9604 cause weight loss?

AOD-9604 showed modest fat reduction in some Phase II trials but results were inconsistent. The effect size is substantially smaller than GLP-1 agonists like semaglutide. It may have some lipolytic activity, particularly for visceral fat, but is not a meaningful obesity treatment by current standards.

How does AOD-9604 differ from full HGH?

AOD-9604 is just the C-terminal fragment (amino acids 176–191) of HGH responsible for lipolytic activity. It does not stimulate IGF-1, does not cause insulin resistance, and does not have the growth-promoting effects of full HGH. This makes it safer metabolically but also limits its anabolic benefits.

What is AOD-9604's safety profile?

AOD-9604 obtained FDA GRAS (Generally Recognized as Safe) status from Phase II trials — making it one of the few research peptides with formal human safety validation. No IGF-1 elevation or insulin resistance was observed in trials. The safety profile was acceptable.

AOD-9604 vs semaglutide for fat loss — which is better?

This comparison is not close. Semaglutide (Ozempic/Wegovy) consistently produces 10–15% body weight reduction in clinical trials. AOD-9604's Phase II trials showed modest and inconsistent results. If the goal is meaningful fat loss, GLP-1 agonists have overwhelmingly stronger evidence.

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