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AOD-9604

unknown risk

Also: Anti-Obesity Drug 9604 · HGH Fragment 177-191

Preliminary Research Only

AOD-9604 is the lipolytic fragment of human growth hormone (amino acids 177-191), modified for stability. It specifically targets fat metabolism without the anabolic effects of full HGH, having completed a Phase 3 obesity trial that did not achieve primary endpoints.

Molecular Weight
1817.1 g/mol
Formula
C78H123N23O23S2
Common Dosing
500 mcg/day subcutaneous (from Phase 3 trial)
Category
research
Last Reviewed
2025-01-15

Reported Benefits

Fat Metabolism

Preliminary 12 studies

Activates lipolytic pathways in adipose tissue; inhibits lipogenesis in animal studies.

Weight Loss

Insufficient 5 studies

Phase 3 trial (METRO) did not meet primary weight loss endpoints.

Cartilage Repair

Preliminary 4 studies

Limited data suggests potential for osteoarthritis application.

Mechanism of Action

AOD-9604 activates beta-3 adrenergic receptors in adipose tissue, stimulating lipolysis (fat breakdown) without activating IGF-1 receptor or inducing insulin resistance — distinguishing it from full-length HGH. The mechanism is specific to the C-terminal fragment's interaction with adipocyte receptors.

Key Clinical Studies

White HM et al. (2009)

RCT · Phase 3 METRO trial

Failed primary weight loss endpoint vs placebo; secondary metabolic benefits noted

Overview

AOD-9604 represents an interesting case study in pharmaceutical peptide development: a fragment of natural HGH specifically engineered to retain only the lipolytic (fat-burning) activity while eliminating the diabetogenic and anabolic effects. It reached Phase 3 clinical trials but ultimately failed to demonstrate sufficient weight loss efficacy for regulatory approval.

Phase 3 Failure Context

The METRO trial enrolled over 500 participants but did not achieve statistically significant weight loss vs. placebo. This is a meaningful negative finding that distinguishes AOD-9604 from peptides with no human trial data. The failure does not rule out all potential applications — secondary endpoints showed metabolic improvements, and the cartilage repair indication remains under investigation.

Fragment 176-191 Confusion

The related compound “Fragment 176-191” refers to a slightly different numbering of the same HGH C-terminal region. These are often conflated in consumer markets but may have slightly different activity profiles. AOD-9604 includes a specific modification (tyrosine at position 177) that enhances stability.

Research Status

Despite Phase 3 failure for obesity, research continues for joint/cartilage applications. Nutraceutical status has been pursued in some markets with regulatory success as a food supplement ingredient.

Regulatory Status

Research Only

FDA Generally Recognized as Safe (GRAS) status sought but not granted; Phase 3 obesity trial conducted; no approval

Safety Profile

Side Effects

  • Injection site reactions
  • Headache (mild)
  • Transient nausea

Contraindications

  • Active malignancy
  • Pregnancy

Drug Interactions

  • Insulin

Primary Uses

Fat metabolismWeight lossCartilage repairAnti-obesity

Weekly Briefing

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Disclaimer: This information is for educational and research purposes only. Not medical advice. Consult a qualified healthcare provider before using any compound.