The C-Terminal Fragment (176-191)
AOD-9604 (Advanced Obesity Drug) is a synthetic analog corresponding to the C-terminal fragment (residues 176-191) of human Growth Hormone, stabilized with an additional N-terminal tyrosine. It was engineered specifically to isolate the lipolytic (fat-burning) properties of hGH while stripping away its systemic growth and metabolic side effects.
Unlike full-length hGH or secretagogues (e.g., Tesamorelin, Ipamorelin), AOD-9604 does not bind to the primary Growth Hormone Receptor (GHR). Instead, it mimics the lipolytic domain of hGH, acting directly on white adipose tissue through the upregulation of beta-3 adrenergic receptors (β3-AR).
Metabolic Decoupling: Zero IGF-1 Impact
The primary clinical advantage of AOD-9604 is its complete lack of metabolic disruption. Because it lacks the active domains of the 191-amino acid hGH molecule, it cannot trigger the hepatic cascade that produces IGF-1. This means AOD-9604 does not stimulate cellular proliferation, long bone growth, or cartilage expansion.
Crucially, AOD-9604 does not induce insulin resistance or negatively impact fasting glucose—the most common limiting factor in long-term GH or secretagogue administration. In a heavily cited 12-week clinical trial involving obese subjects (Heffernan et al., 2001), administration of AOD-9604 resulted in a 2.6 kg weight loss (compared to 0.8 kg in placebo) with zero detected alterations to IGF-1 levels or glucose tolerance.
Clinical Dosing Protocol
AOD-9604 administration must be rigorously timed around fasting windows due to its reliance on the β3-AR pathway. The presence of insulin powerfully inhibits lipolysis; injecting AOD-9604 in a fed state actively blunts its efficacy.
• The Standard Dose: 250mcg to 300mcg per day, administered subcutaneously via an insulin syringe into visceral adipose tissue (typically the abdomen).
• Timing Protocol: Injections must occur strictly fasted. The optimal window is immediately upon waking, followed by 30-60 minutes of fasted, low-intensity steady-state (LISS) cardio to maximize free fatty acid oxidation. Do not consume calories (especially carbohydrates) for at least 1-2 hours post-injection.
• Cycle Duration: AOD-9604 is typically run for 8-12 weeks, followed by a washout period to prevent potential receptor desensitization, though its benign side effect profile allows for longer deployment compared to potent secretagogues.