AOD-9604 vs Retatrutide

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.

Triple GIP/GLP-1/glucagon receptor agonist; targets three pathways for synergistic fat reduction

Retatrutide (LY3437943) is an investigational triple hormone receptor agonist that simultaneously activates GLP-1, GIP (glucose-dependent insulinotropic polypeptide), and glucagon receptors, combining the complementary metabolic actions of all three incretin and counterregulatory hormone pathways in a single weekly injection. The GLP-1 component drives satiety and insulin secretion, GIP enhances adipose lipid metabolism and further modulates appetite, and glucagon receptor activation increases energy expenditure — together producing greater weight loss than single or dual agonists in the same receptor class. A Phase 2 randomized controlled trial published in the New England Journal of Medicine demonstrated dose-dependent weight reductions of up to 24% of body weight at 48 weeks, among the largest reported for any pharmacological obesity treatment. Retatrutide has not received FDA approval; it is under Phase 3 registrational evaluation (TRIUMPH trials) as of 2025 for obesity, obstructive sleep apnea, and knee osteoarthritis. Retatrutide cost and access As of mid-2026, retatrutide has not received FDA approval and is not commercially available as a branded pharmaceutical. It is in late-stage (Phase 3) clinical development through Eli Lilly. Access pathways include: enrollment in active clinical trials (listed on ClinicalTrials.gov), research-use peptide vendors who supply retatrutide for laboratory/research contexts (not for human use), and a limited number of compounding pharmacies that compound investigational or pre-approval compounds under provider-supervised protocols. Cost per month of research-grade retatrutide from vendors varies considerably by quantity and formulation. Branded pharmaceutical pricing will be established at approval; given tirzepatide's pricing trajectory and the triple-agonist mechanism, analyst forecasts suggest a premium pricing position relative to existing GLP-1 agonists. Retatrutide vs survodutide: Survodutide (BI 456906, Boehringer Ingelheim + Zealand Pharma) is a dual GLP-1 and glucagon receptor agonist in Phase 3 development for MASH (metabolic dysfunction-associated steatohepatitis) and obesity. Compared to retatrutide, survodutide lacks the GIP receptor component; retatrutide's triple agonism adds GIP-mediated adipose lipid oxidation to the GLP-1 + glucagon combination. In trial comparisons, both compounds show substantial weight reductions (retatrutide 24.2% at 12mg/week in Phase 2; survodutide 18.7% at highest dose in Phase 2). Neither compound has a direct head-to-head trial yet. Both represent the next tier beyond tirzepatide in the GLP-1 + additional agonism category. Retatrutide's MASH indication (liver fat reduction) also overlaps with survodutide's primary development focus. The competitive landscape in this category is evolving rapidly as multiple Phase 3 readouts are expected through 2026–2027.