AOD-9604 vs Tirzepatide

AOD-9604 stimulates lipolysis and inhibits lipogenesis through mechanisms believed to be independent of the insulin-like growth factor pathway. It appears to mimic the fat-metabolising action of growth hormone without triggering the proliferative effects associated with full GH or GH-releasing peptides. Oral bioavailability has been observed in some formulations, making it of interest for non-injectable protocols.

AOD-9604 (anti-obesity drug 9604; Tyr-hGH(177–191)) is a synthetic 16-amino-acid peptide corresponding to the C-terminal lipolytic fragment of human growth hormone, modified with an N-terminal tyrosine residue for stability, and investigated as a candidate anti-obesity compound on the premise that the lipolytic activity of hGH resides in this C-terminal domain — separable from the growth-promoting and insulin-antagonizing effects mediated by other regions of the full-length molecule. AOD-9604 is proposed to stimulate fat metabolism through beta-3 adrenergic receptor-mediated pathways without activating IGF-1 production or the anabolic receptor domains of full-length GH, making it theoretically safer than GH itself for metabolic applications; preclinical studies in obese mice demonstrated lipolytic effects and body weight reduction. Clinical trials were conducted in humans by Metabolic Pharmaceuticals, and Phase 2/3 data generated in Australia suggested modest weight loss effects; however, the primary trial results were never published in PubMed-indexed peer-reviewed journals, and the best indexed primary evidence for AOD-9604 remains a preclinical study in obese mice demonstrating effects on lipid metabolism. AOD-9604 has no FDA approval and no approved indication in any jurisdiction; despite its human clinical program, the absence of published peer-reviewed primary trial data means clinical efficacy and safety cannot be independently evaluated, and the compound is currently available only as a research peptide. AOD-9604 is supplied as a lyophilized powder requiring reconstitution with bacteriostatic water before subcutaneous administration; the volume of BAC water added to the vial determines the concentration of the resulting solution, following standard peptide reconstitution methodology. Research on AOD-9604 peptide dosage was conducted in both the preclinical obese-mouse model and the Phase 2/3 human clinical program in adult obesity populations; clinical trial dosage data exists from the Metabolic Pharmaceuticals program, though primary results were not published in indexed peer-reviewed journals. Oral formulations of AOD-9604 were also evaluated in the clinical program as an alternative to subcutaneous delivery. AOD-9604 dosage context In the Metabolic Pharmaceuticals clinical program, AOD-9604 was evaluated at oral doses of 1mg and 9mg daily, and via subcutaneous injection at approximately 1mg/day in Phase 2/3 human obesity studies. In the research peptide community, subcutaneous protocols commonly reference 250–300mcg once daily, administered to the subcutaneous adipose tissue of the abdomen. These figures derive from the research context rather than an approved clinical protocol — AOD-9604 has no approved dosing for any human indication. Reconstitution follows standard peptide preparation: a 5mg vial combined with 2mL bacteriostatic water yields 2,500mcg/mL (0.1mL = 250mcg per injection). Oral formulations were evaluated in the clinical trial as a potential non-injectable route; no commercial oral AOD-9604 product exists. AOD-9604 side effects and safety profile The safety data from AOD-9604's clinical program includes several notable findings: no elevation in IGF-1 levels was observed at studied doses — a key distinction from full-length growth hormone, where IGF-1 elevation drives concerns about cell proliferation and potential oncogenicity. No significant disruption of fasting glucose or insulin sensitivity was documented. No serious adverse events attributable to AOD-9604 were reported in published trial summaries. The absence of anabolic receptor activity (no binding to the GH receptor growth-promoting domain) is the proposed basis for this benign safety profile compared to GH itself. Long-term safety data does not exist due to the absence of Phase 3 completion and product approval. Research-grade AOD-9604 carries standard purity and contamination risks associated with unregulated compounding. Providers offering AOD-9604 through supervised clinical programs are searchable in the PeptideBase provider directory.

Tirzepatide is a dual agonist of both GLP-1 and GIP (glucose-dependent insulinotropic polypeptide) receptors. GIP receptor activation adds a complementary mechanism to GLP-1 agonism — enhancing insulin secretion, reducing glucagon, and modulating adipose tissue metabolism independently of GLP-1 pathways. The combination produces greater average weight reduction in clinical trials than selective GLP-1 agonists at comparable doses.

Tirzepatide is a once-weekly injectable dual agonist of GLP-1 and GIP receptors, FDA approved for type 2 diabetes (Mounjaro) and weight management (Zepbound). Clinical trials demonstrate weight reductions exceeding those seen with semaglutide in head-to-head comparisons. Compounded formulations are offered by telehealth and functional medicine providers across the US. It represents the current clinical benchmark for pharmacological weight management. Mechanism of action: Tirzepatide activates two incretin receptors simultaneously — the glucagon-like peptide-1 (GLP-1) receptor and the glucose-dependent insulinotropic polypeptide (GIP) receptor. GLP-1 activation suppresses appetite, slows gastric emptying, and potentiates insulin secretion; GIP activation independently stimulates insulin release and may reduce some of the GI side effects associated with pure GLP-1 agonism. The dual mechanism produces greater appetite suppression and metabolic improvement than either receptor pathway alone, which accounts for the superior weight reduction seen in clinical trials relative to semaglutide. Clinical evidence: The SURMOUNT trial program established tirzepatide's weight reduction profile. SURMOUNT-1 (2022) found a mean weight reduction of 22.5% over 72 weeks at the highest dose (15mg/week) vs 2.4% with placebo — the largest mean weight reduction reported for any approved pharmacological intervention at that time. SURMOUNT-5 (2024) was a direct head-to-head comparison with semaglutide 2.4mg: tirzepatide 10mg and 15mg produced significantly greater weight reductions (20.2% vs 13.7% for semaglutide). The SURPASS trials established cardiometabolic and glycaemic benefits in T2D contexts. Tirzepatide vs semaglutide: Tirzepatide's dual GIP+GLP-1 mechanism produces greater mean weight reductions in trials but also a distinct side effect profile. GI tolerability may be slightly better than pure GLP-1 agonism for some users due to the GIP component, though nausea and gastrointestinal symptoms remain the most common adverse effects. Semaglutide has a larger body of long-term safety data; tirzepatide has superior head-to-head efficacy data. Prescribers select between them based on clinical context, cost, access, and patient response history. Access and regulatory status: Tirzepatide requires a prescription from a licensed provider. Branded formulations (Mounjaro, Zepbound) are available at licensed pharmacies. Compounded tirzepatide has been subject to evolving FDA guidance around shortage status; access through compounding channels varies by jurisdiction and regulatory period. Providers offering tirzepatide-based programs are indexed in the PeptideBase directory.