AOD-9604 — Research Reference

AOD-9604 (Advanced Obesity Drug 9604) is a stabilised synthetic analogue based on the C-terminal region (approximately residues 177–191) of human growth hormone (HGH), with a tyrosine residue added at the N-terminus to enhance structural stability. It was developed by Metabolic Pharmaceuticals (Melbourne, Australia) as a candidate therapeutic for obesity, on the basis that this region of HGH drives fat metabolism without the anabolic, blood glucose, and IGF-1 effects associated with full-length growth hormone.

AOD-9604 received FDA Investigational New Drug (IND) status and progressed through Phase 2 and Phase 3 clinical trials. The Phase 3 obesity trials did not meet their primary endpoint for weight loss, though the compound was reported to be well-tolerated in human trials.

Quick Reference

Overview

The research hypothesis underlying AOD-9604 is that the fat-metabolising activity of growth hormone resides in its C-terminal region. Full-length HGH has anabolic effects (muscle growth, IGF-1 elevation, insulin antagonism) that are primarily attributed to its N-terminal region and receptor binding characteristics. Research into the C-terminal fragment of HGH began in the 1990s, with studies demonstrating that this region stimulates lipolysis (fat breakdown) and inhibits lipogenesis (fat storage) in animal models without producing the blood glucose elevation, IGF-1 elevation, or anabolic effects associated with full HGH.

AOD-9604 differs from the “raw” HGH Fragment 176-191 in that it incorporates a tyrosine residue at the N-terminus and corresponding structural modifications that improve in vitro and in vivo stability. The compound was designated “AOD-9604” as a reference to Metabolic Pharmaceuticals’ compound numbering, and both names are used in the research literature. The two compounds are sometimes used interchangeably in anecdotal research contexts, though AOD-9604 strictly refers to the stabilised pharmaceutical-grade variant.

The proposed mechanism of lipolytic activity involves β3-adrenergic receptor stimulation in adipocytes, promoting the breakdown of stored triglycerides into free fatty acids and glycerol. This is distinct from the mechanism of GLP-1 agonists or other fat-loss compounds.

Reported Protocols

Subcutaneous Administration

Subcutaneous injection is the primary reported administration route. Commonly reported doses range from 250 mcg to 500 mcg per day, administered as a single morning injection or split into two daily injections.

• Single morning injection: 500 mcg administered subcutaneously upon waking, in a fasted state, is the most commonly reported protocol in anecdotal accounts.
• Split dosing: Some research accounts describe 250 mcg twice daily (morning and pre-workout or pre-sleep), though the single morning injection is more frequently cited.
• Fasted administration: Administration in a fasted state is commonly reported to maximise the lipolytic effect; elevated insulin may attenuate fat-mobilising activity.
• Cycle duration: Commonly reported cycles range from 4 to 12 weeks.

Oral Administration Note

Some anecdotal accounts describe oral AOD-9604 administration. The oral bioavailability of peptides is generally poor due to enzymatic degradation in the GI tract, and oral AOD-9604 has not been established to produce the same systemic effects as subcutaneous injection in controlled research.

Reported Effects

Lipolysis (Fat Breakdown)

Research has investigated AOD-9604 for its potential role in stimulating lipolysis in adipose tissue via β3-adrenergic receptor activation. Preclinical studies have reported fat mass reduction in obese animal models without changes in blood glucose or IGF-1. Human Phase 2 trials conducted by Metabolic Pharmaceuticals reported body fat reduction in some participant groups, though Phase 3 primary endpoints were not met.

Lipogenesis Inhibition

Research has investigated AOD-9604 for its potential role in inhibiting lipogenesis — the synthesis of new fatty acids and their storage in adipocytes. This dual action of promoting fat breakdown while inhibiting fat accumulation is proposed as the basis for the compound’s fat-selective effects.

No Reported Anabolic or IGF-1 Effects

A key reported distinction from full-length HGH is that AOD-9604 does not appear to elevate IGF-1 or produce anabolic effects on muscle or bone in research at commonly reported doses. Research has not reported the insulin antagonism, blood glucose elevation, or carpal tunnel effects associated with full HGH administration.

No Reported Blood Glucose Effect

Research and clinical trial data have not identified blood glucose changes with AOD-9604 at doses used in obesity research, consistent with the hypothesis that glucose regulation is mediated by HGH’s N-terminal region rather than the C-terminal fragment.

Reported Side Effects

Reported side effects in research and anecdotal accounts include the following.

Human clinical trials (Phase 2 and Phase 3) reported AOD-9604 to be generally well-tolerated. The compound has been reported not to produce the edema, joint pain, insulin resistance, or IGF-1 elevation associated with full-length synthetic GH.

Storage & Handling

Lyophilized Powder (Unreconstituted)

• Refrigerator (2–8°C): Preferred; reported stable for 12 months or more
• Room temperature: Short-term stability acceptable; refrigerator strongly preferred
• Freezer: Acceptable for long-term storage; avoid repeated freeze-thaw cycles
• Protect from light and moisture

Reconstituted Solution

• Refrigerator (2–8°C): Use within 4–6 weeks of reconstitution
• Do not freeze reconstituted AOD-9604
• Bacteriostatic water is the preferred diluent for multi-dose vials
• Discard if the solution becomes cloudy or shows particulate matter

See the Reconstitution Guide for step-by-step instructions.

Frequently Asked Questions

What is the difference between AOD-9604 and HGH Fragment 176-191? HGH Fragment 176-191 refers to the exact C-terminal 16 amino acids (residues 176–191) of human growth hormone as a raw fragment. AOD-9604 is a stabilised pharmaceutical-grade derivative of this region, incorporating a tyrosine residue at the N-terminus and structural modifications that improve stability. Both compounds are studied for lipolysis and fat metabolism. AOD-9604 was developed as a drug candidate and progressed through clinical trials; Fragment 176-191 is studied as a research compound. In anecdotal research contexts, the two names are sometimes used interchangeably. See the HGH Fragment 176-191 profile for comparison.

Does AOD-9604 affect growth hormone or IGF-1? Research and clinical trial data have not identified meaningful changes in GH or IGF-1 at commonly reported research doses. This selectivity for fat metabolism without anabolic hormone elevation is the primary pharmacological distinction from full-length HGH.

Was AOD-9604 in clinical trials? Yes. AOD-9604 received FDA Investigational New Drug (IND) status and was investigated in Phase 2 and Phase 3 clinical trials for obesity by Metabolic Pharmaceuticals. The Phase 3 primary endpoint for body weight reduction was not met, and the compound was not advanced to regulatory approval. The clinical trial programme established a human safety profile.

Can AOD-9604 be stacked with other fat-loss peptides? Anecdotal research accounts describe combining AOD-9604 with GLP-1 agonists or other metabolic compounds. No clinical data on combination approaches is available.

Related Pages

Goals: Fat Loss · Appetite & Weight Management

Class: Fat Loss & Lipolytic Peptides

References & Further Reading

• Heffernan M, et al. (2001). The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following diet in obese mice. International Journal of Obesity, 25(10), 1442–1449. PubMed →
• Ng FM, et al. (1990). Metabolic effects of a synthetic human growth hormone fragment. Molecular and Cellular Endocrinology, 74(1–2), 75–83. PubMed →
• Heffernan MA, et al. (2000). The effects of a synthetic growth hormone fragment on obesity-related indicators. Endocrinology, 141(1), 422–427. PubMed →