The evidence base for AOD-9604 includes early obesity-focused development and growth-hormone-fragment pharmacology, but it did not become an FDA-approved metabolic drug. Published evidence does not support broad consumer weight-loss claims.
Physicians may submit patient-specific prescription requests for AOD-9604 for pharmacy review. Certain preparations may be available now when clinically appropriate, lawfully prescribed, supported by patient-specific documentation, and approved by the dispensing pharmacy. Availability is determined case by case. This is not a consumer access promise; it is a clinical, sourcing, formulation, and regulatory review process. This ingredient is part of an evolving FDA review process for peptide-related bulk substances used in compounding.
A patient-specific prescription request is not a weight-loss product listing. It must be tied to clinician documentation, pharmacy review, ingredient sourcing, and formulation feasibility before any dispensing decision.
In brief
AOD-9604 Explained
AOD-9604 is a short synthetic peptide that was designed to copy a small piece (residues 177, 191) of human growth hormone, the piece that animal studies suggested could help burn fat 1. The Australian biotech Metabolic Pharmaceuticals developed AOD-9604 in the late 1990s and 2000s as a candidate obesity drug 7. The hope was that the fragment would retain the fat-burning effects of growth hormone without raising blood sugar or causing growth-hormone-like side effects 56.
AOD-9604 has no FDA approval in the United States. This ingredient is part of an evolving FDA review process. Physicians may submit patient-specific prescription requests for pharmacy review. Availability is determined case by case, and availability may change after FDA review, PCAC discussion, final agency action, or state-board guidance.
At a glance
Quick Facts About AOD-9604
Category
Synthetic 16-amino-acid analogue of the C-terminal fragment (residues 177, 191) of human growth hormone (hGH), engineered to retain lipolytic activity without GH-like effects on linear growth or IGF-1
Active ingredient
AOD-9604 (also written AOD9604), a tyrosylated 16-residue peptide derived from the human growth hormone 177, 191 lipolytic domain
FDA-approved branded forms
None. AOD-9604 has no FDA-approved indication or branded product in the United States.
Route
Subcutaneous injection in clinical trials; oral and sublingual routes studied preclinically with limited bioavailability data
Evidence posture
Preclinical rodent studies (Heffernan, Ng) characterize lipolytic and fat-oxidation effects; one phase 2b obesity program in adults run by Metabolic Pharmaceuticals (Australia) reported failure to meet the primary weight-loss endpoint and human obesity development was discontinued
FDA-approval status
Category 2, evolving FDA review process. Valid patient-specific prescription required; supporting clinical rationale may be requested.
Compounded under
Physicians may submit patient-specific prescription requests for pharmacy review. Availability is determined case by case.
Australian regulatory note
AOD-9604 was at one point notified to the Australian TGA as an ingredient considered acceptable for use in cosmetic and dietary contexts; this notification is jurisdiction-specific to Australia and does not extend to US drug status
Prescription review
Patient-Specific Prescription Only
Physicians may submit patient-specific prescription requests for AOD-9604 for pharmacy review. Certain preparations may be available now when clinically appropriate, lawfully prescribed, and approved by the dispensing pharmacy. Availability is determined case by case.
Made to order, not off a shelf. No batch sits in a warehouse waiting for buyers. Your prescription is what triggers the prep.
Named-patient label. The bottle carries your name. The batch records carry your prescription.
Dose, strength, and route chosen for you. A prescriber who knows your chart decides what gets compounded, not a manufacturer who set the strength for a trial population.
Licensed pharmacist on the hook. A real person, with a license that can be pulled, signs off on every prep. State inspectors check the facility.
Compounded drugs are not FDA-approved. They should not be evaluated using branded-drug trial data. Availability varies by state and prescribed medication.
A research-use-only website ships a vial from a warehouse. There is no prescription, no pharmacist, no facility inspection, and no way to recall the product if something is wrong with it. If the vial is mislabeled, contaminated, or under-potent, there is nobody whose license is at stake.
A 503A compounding pharmacy is the other thing. Your doctor writes the prescription. A licensed pharmacist, whose name is on the label, prepares the medicine in a facility the state inspects. If something goes wrong, there is a person and a license on the hook, and a documented chain of custody on every lot. That accountability is what makes it safe.
What it is
What is AOD-9604?
AOD-9604 is a synthetic peptide corresponding to a modified form of the C-terminal sequence (residues 177, 191) of human growth hormone, with an additional N-terminal tyrosine residue. Native hGH is a 191-amino-acid protein with multiple functional domains; the 177, 191 segment was identified in the 1990s by Ng, Heffernan, and colleagues at Monash University and the University of Melbourne as carrying the lipolytic / fat-oxidation activity of the parent hormone in rodent models without the somatogenic (growth-promoting) and glycemic effects mediated through the intact hGH receptor 13.
AOD-9604 was developed under that hypothesis by Metabolic Pharmaceuticals Ltd, a Melbourne-based biotechnology company spun out from Monash University. The molecule was advanced into preclinical and clinical development as a candidate anti-obesity peptide. Subsequent structural and conformational work 4 characterized cyclized and modified analogues of the same C-terminal domain. The compound is most commonly described in the literature as 'AOD-9604', 'AOD9604', or 'tyr-hGH(177-191)'.
There is no FDA-approved finished drug product containing AOD-9604. In the published clinical-development era, investigational supply was prepared as a sterile peptide solution for subcutaneous injection 7; oral and sublingual administration was also explored preclinically with limited oral bioavailability data 3.
How it works
How AOD-9604 Works
Class
GH C-terminal fragment
First studied
Early 2000s
Current status
Category 2, evolving FDA review process
Compounding category
Patient-specific 503A on physician request, pending broader FDA review
The mechanistic rationale for AOD-9604 originates from work characterizing the C-terminal region of human growth hormone as a discrete lipolytic domain. Ng and colleagues reported that synthetic peptides derived from residues 177, 191 of hGH stimulate lipolysis and inhibit lipogenesis in adipocytes and adipose tissue from obese rodents without engaging the intact growth-hormone receptor pathway that mediates linear growth, IGF-1 elevation, and glucose intolerance 12. The compound's putative selectivity for the lipolytic phenotype over the somatogenic phenotype was the central design hypothesis.
In rodent studies, AOD-9604 increases whole-body fat oxidation and reduces adipose mass in genetically obese (ob/ob) and diet-induced obese mice 56. Heffernan et al. (2001) used β3-adrenergic receptor knockout mice to argue that the lipolytic effect of AOD-9604 in mice did not strictly depend on β3-AR signaling, distinguishing the proposed mechanism from classical sympathomimetic lipolytics. Oral administration of a synthetic fragment of human growth hormone in the same model system 3 reported reductions in adiposity, although oral bioavailability of peptide drugs is generally poor and the translational relevance of the oral preclinical signal to human subcutaneous dosing remained uncertain.
Importantly, the rodent mechanistic data have not been replicated in adequately powered human pharmacology studies in the peer-reviewed literature. Investigational-drug reviews from the development era 798 described the mechanistic rationale and the early clinical pharmacology, but no published human pharmacodynamic study demonstrates a sustained, clinically meaningful increase in fat oxidation or reduction in adipose mass that matches the rodent phenotype.
Research history
AOD-9604 Research History
AOD-9604 was developed by Metabolic Pharmaceuticals Ltd, a Melbourne biotechnology company founded on intellectual property from Monash University and the University of Melbourne characterizing the lipolytic domain of human growth hormone 123. The discovery work was led by F.M. Ng and the in vivo pharmacology by M.A. Heffernan and colleagues; foundational peer-reviewed reports appeared in 2000 and 2001 5.
Clinical development through the 2000s targeted adult obesity 810. Investigational-drug reviews from 2004, 2007 catalog AOD-9604 alongside other peptide and small-molecule anti-obesity candidates of the era 4. Khan et al. (2012) included AOD-9604 in a broader review of medical management of obesity, summarizing the development status as inactive in obesity 11. The pivotal phase 2b weight-loss study run by Metabolic Pharmaceuticals failed to meet its primary endpoint for clinically meaningful weight loss versus placebo, and the company announced in 2007 that it was discontinuing obesity development 69. The trial was not published in the indexed peer-reviewed literature; the development outcome is described in the investigational-drug reviews cited above 711. No subsequent phase 3 obesity program has been undertaken 15.
After the obesity program closed, two distinct strands of work appeared. Kwon and Park (2015) reported a preclinical study of intra-articular AOD-9604 with and without hyaluronic acid in a rabbit osteoarthritis model 16, suggesting a potential cartilage-protective signal in that small-animal study. Separately, the sports anti-doping research community has continued analytical characterization of AOD-9604 because of its appearance in illicit performance-enhancing peptide preparations 1314. There is no recent peer-reviewed human-efficacy trial program for AOD-9604 in any indication 12.
Timeline
AOD-9604 Timeline
2000Ng et al 1. (Hormone Research), Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone in obese rodent adipose tissue
2000Ng et al 2. (J Mol Endocrinol), Molecular and cellular actions of the related structural domain AOD9401 in Zucker fatty rats
2000Heffernan et al 3. (Am J Physiol Endocrinol Metab), Oral administration of a synthetic hGH C-terminal fragment in rodents
2000Ogru et al 4. (J Peptide Res), Conformational and biological analysis of a cyclic anti-obesity peptide from the hGH C-terminal domain
2001Heffernan et al 6. (Int J Obes), Chronic hGH or modified C-terminal fragment increases fat oxidation and reduces weight in obese mice
2001Heffernan et al 5. (Endocrinology), AOD-9604 chronic treatment in obese and β3-AR knockout mice; weight and lipid-metabolism effects partially independent of β3-AR signaling
2006Halford (Curr Opin Investig Drugs) and Jensen (Obesity), investigational-drug landscape reviews covering AOD-9604 alongside other clinical-stage anti-obesity candidates 89
2007Metabolic Pharmaceuticals announces failure of the AOD-9604 phase 2b adult obesity study to meet its primary weight-loss endpoint; obesity development is discontinued 71110. Zieba (Postepy Hig Med Dosw) reviews the broader anti-obesity pipeline of the era including AOD-9604.
2012Khan et al 11. (Recent Pat Endocr Metab Immune Drug Discov), review of medical management of obesity catalogs AOD-9604 development status as inactive in obesity
2013Orlovius et al 12. (Drug Test Anal), AOD-9604 does not cross-react with the WADA hGH isoform immunoassay; analytical-detection groundwork
2014Vanhee et al. (Drug Test Anal), AOD-9604 identified in unknown pharmaceutical preparations seized by Belgian authorities; Thevis et al 1314. review analytical approaches to detection of emerging non-approved drugs in doping controls
2015Cox et al 15. (Drug Test Anal), detection and in vitro metabolism of AOD-9604 in support of sports doping controls
2015Kwon and Park (Ann Clin Lab Sci), preclinical rabbit osteoarthritis model: intra-articular AOD-9604 with or without hyaluronic acid suggests cartilage-related signal in small-animal study 16
2019FDA Pharmacy Compounding Advisory Committee proceedings and subsequent FDA Category lists place AOD-9604 on the 503A bulk drug substances Category 2 list, nominated substances under agency review whose use in 503A compounding raises significant safety risks pending evaluation 17
Natural role
Biological Role of AOD-9604
Human growth hormone (hGH) is a 191-amino-acid pituitary peptide that signals through the growth-hormone receptor to drive longitudinal growth, hepatic IGF-1 production, and a set of metabolic effects including lipolysis, increased lean mass, and (at supraphysiologic exposure) insulin resistance 7. The 177, 191 C-terminal segment was proposed in the 1990s and 2000s as a region carrying a discrete lipolytic phenotype distinct from the somatogenic effects of intact hGH 13.
AOD-9604 is a synthetic analogue of this region, designed to retain the proposed adipose-tissue effect while sparing the systemic GH/IGF-1 axis. The biological framing is therefore narrower than for incretin-axis peptides or melanocortin-axis peptides: AOD-9604 is best understood as a candidate selective lipolytic agent rather than as a hormone replacement or a broad metabolic peptide 7. The clinical translational track has not validated the rodent biology in adequately powered human trials.
Investigated in a phase 2b weight-loss trial that did not meet its primary endpoint; clinical development for obesity discontinued. AOD-9604 has no FDA approval for weight management.
Metabolic Pharmaceuticals advanced AOD-9604 through phase 1 and phase 2 clinical development for adult obesity through the 2000s on the basis of rodent lipolytic and fat-oxidation data 156. Investigational-drug-pipeline reviews from the era described the program and dosing strategy 789. The pivotal phase 2b obesity study did not show a clinically meaningful weight-loss difference versus placebo at the primary endpoint, and Metabolic Pharmaceuticals discontinued the obesity development program in 2007 1110. The phase 2b trial was not published in the indexed peer-reviewed literature; the program failure is documented in subsequent review articles cataloging the anti-obesity pipeline. No phase 3 obesity development has been undertaken since.
Single rabbit-model preclinical study; no human trials.
Kwon and Park (2015) reported intra-articular AOD-9604, alone or combined with hyaluronic acid, in a rabbit model of knee osteoarthritis 16. The study described histologic and imaging signals consistent with reduced cartilage damage in the combined-treatment arm. This is a single small-animal study and has not been followed by human trials; the finding is hypothesis-generating only.
Not a clinical use. AOD-9604 has appeared in illicit international peptide markets and is monitored by sports anti-doping laboratories.
AOD-9604 has been detected in unknown pharmaceutical preparations seized by national authorities 13 and is the subject of analytical-method development for sports doping controls 121514. These analytical studies do not establish clinical efficacy or a clinical role; they document the substance's presence in unregulated supply chains and its detection chemistry. RonanRx flags this context because the unregulated international peptide market is the principal route by which AOD-9604 reaches end-users today.
FDA-approved use
FDA-Approved Uses of AOD-9604
AOD-9604 has no FDA-approved indication and no FDA-approved branded finished drug product. It has never received a new drug application (NDA) approval, an abbreviated new drug application (ANDA) approval, a biologics license application (BLA) approval, or an over-the-counter (OTC) monograph listing in the United States. There is no FDA-approved label, no approved patient population, no approved dosing regimen, and no approved manufacturer.
AOD-9604 has no FDA approval in the United States. This ingredient is part of an evolving FDA review process. Physicians may submit patient-specific prescription requests for pharmacy review. Availability is determined case by case, and availability may change after FDA review, PCAC discussion, final agency action, or state-board guidance.
Compounded use
Compounded AOD-9604 (503A)
Physicians may submit patient-specific prescription requests for pharmacy review. For AOD-9604, certain preparations may be available now when clinically appropriate, lawfully prescribed, and approved by the dispensing pharmacy. Availability is determined case by case and may depend on patient-specific documentation, ingredient status, source qualification, formulation feasibility, state requirements, and pharmacist judgment. The review starts with the evidence constraint: The evidence base for AOD-9604 includes early obesity-focused development and growth-hormone-fragment pharmacology, but it did not become an FDA-approved metabolic drug. Published evidence does not support broad consumer weight-loss claims.
This ingredient is part of an evolving FDA review process. RonanRx is monitoring FDA's PCAC process and any subsequent agency action. This ingredient is part of an evolving FDA review process for peptide-related bulk substances used in compounding. Availability may change after FDA review, PCAC discussion, final agency action, or state-board guidance. For AOD-9604, RonanRx ties that monitoring to the evidence limits described above and to any patient-specific documentation submitted by the prescriber.
Valid patient-specific prescription required. Supporting clinical rationale may be requested. Compounded medications are not FDA-approved. No consumer self-ordering, no office stock, no bulk dispensing. Requests for AOD-9604 are reviewed before any preparation is made or released. A patient-specific prescription request is not a weight-loss product listing. It must be tied to clinician documentation, pharmacy review, ingredient sourcing, and formulation feasibility before any dispensing decision.
Per Metabolic Pharmaceuticals investigational protocols (1990s, 2000s); not commercially supplied
Sterile peptide solution for subcutaneous administration used in phase 1 and phase 2 trials run by Metabolic Pharmaceuticals. No FDA-registered manufactured product exists. No FDA-cleared compounded formulation exists.7
Unregulated grey-market preparations
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AOD-9604 has been identified in pharmaceutical preparations seized by national authorities and in research-grade peptide supply chains [vanhee2014, cox2015]. These preparations are outside any regulated quality system and are not eligible for clinical use; RonanRx does not source, dispense, or counsel on grey-market AOD-9604.1315
Routes used in published literature: subcutaneous, intramuscular, oral, sublingual.
Doses described in investigational-drug reviews ranged from approximately 0.25 mg to 1 mg subcutaneously, typically once daily, over weeks of dosing. The phase 2b weight-loss trial did not meet its primary endpoint, and no labeled dose exists.
Up to 12 weeks in the phase 2b program
Historical investigational dosing, no FDA-approved regimen711
Oral
Preclinical rodent obesity models
Oral synthetic hGH C-terminal fragments were dosed in rodent studies; human oral bioavailability of AOD-9604 has not been characterized in the published peer-reviewed literature
Up to several weeks in rodent studies
Preclinical rodent, does not translate to human dosing3
There is no labeled dose for AOD-9604. The Metabolic Pharmaceuticals investigational program used subcutaneous daily dosing in the sub-milligram-to-low-milligram range during phase 1 and phase 2 studies in the 2000s. Because the phase 2b obesity trial did not show a clinically meaningful weight-loss difference versus placebo at the primary endpoint and the obesity program was discontinued, the historical investigational regimens carry no evidence of clinical benefit and should not be reused as a basis for current dosing decisions 11.
Doses described in the unregulated international peptide market (variably reported as 0.25, 1 mg subcutaneously, daily or several times weekly) do not correspond to any FDA-reviewed dosing regimen and are not supported by published human efficacy or safety data. RonanRx does not provide compounded AOD-9604 and does not recommend a dosing regimen for AOD-9604 7.
Doses listed are literature context, not patient instructions. Dosing decisions are made by the prescribing doctor and tailored to the individual patient.
Safety
AOD-9604 Safety
Safety overview
The published human safety database for AOD-9604 is limited to the phase 1 and phase 2 investigational program run by Metabolic Pharmaceuticals in the 2000s, the primary trial reports of which were not published in indexed peer-reviewed journals 79. Investigational-drug reviews from the era describe the development-program tolerability as acceptable at the doses tested, generally without the hyperglycemia, IGF-1 elevation, or fluid-retention adverse-event profile characteristic of intact hGH, but these summaries are secondary descriptions rather than independent safety analyses, and the phase 2b weight-loss study did not yield a positive efficacy signal that would have advanced the molecule into a phase 3 safety database 81110.
There is no published long-term human safety data, no published cardiovascular safety data, no published reproductive or carcinogenicity data, and no FDA safety review. Analytical work has identified AOD-9604 in seized illicit pharmaceutical preparations and in research-grade supply chains; this material is outside any regulated quality system and carries the additional safety considerations typical of unregulated injectable peptides: sterility, endotoxin, identity, and potency cannot be assumed 121315.
The FDA's placement of AOD-9604 on the 503A bulk drug substances Category 2 list 17 signals that the agency has identified significant safety questions about its use in 503A compounding pending agency review. RonanRx treats AOD-9604 as not eligible for compounding during the evolving FDA review process 14.
Contraindications
Honest gap. There is no FDA-approved label for AOD-9604 and no FDA-reviewed list of contraindications, warnings, or precautions. Because there is no FDA-approved indication and AOD-9604 sits on the FDA 503A bulks Category 2 list, RonanRx treats AOD-9604 as not eligible for clinical use, which functions as a categorical contraindication to RonanRx-dispensed use.
Searched: PubMed, FDA Drugs@FDA, DailyMed, FDA 503A bulk drug substances Category 2 list on 2026-05-11 · terms AOD-9604 OR AOD9604 OR "hGH 177-191", contraindications, warnings, precautions.
Drug interactions
Honest gap. No published clinically validated drug-drug interaction data are available for AOD-9604. The molecule has not been characterized in dedicated human CYP-substrate or transporter-substrate studies in the peer-reviewed literature. Cox et al. (2015) reported in vitro metabolism work in the context of doping-control assay development [cox2015]; this does not constitute a clinical DDI assessment.
Searched: PubMed, FDA Drugs@FDA, DailyMed on 2026-05-11 · terms AOD-9604 OR AOD9604 drug interactions, pharmacokinetic interactions, CYP.
Adverse events
Honest gap. No FDA-reviewed adverse-event analysis exists for AOD-9604. The Metabolic Pharmaceuticals phase 1/2 program tolerability data were summarized in investigational-drug reviews [wilding2004, khan2012] as generally acceptable at the doses tested, but the primary trial reports were not published in the indexed peer-reviewed literature. No published FAERS analysis or post-marketing safety database is available because AOD-9604 has never been a marketed FDA-approved drug. Unregulated international supply [vanhee2014, cox2015] carries the additional risks typical of grey-market injectable peptides, sterility, endotoxin, identity, potency, which cannot be characterized at population level in the absence of a regulated supply chain.
Searched: PubMed, FDA FAERS public dashboard, FDA 503A bulks Category 2 documentation on 2026-05-11 · terms AOD-9604 OR AOD9604 adverse events, FAERS, postmarketing, injection-site, hypersensitivity.
Monitoring
Monitoring AOD-9604 Therapy
No RonanRx-specific monitoring protocol has been established for AOD-9604. If a patient-specific prescription is submitted, supporting clinical rationale may be requested, and monitoring expectations would be reviewed case by case against the published evidence, route, sterile or nonsterile status, concomitant therapies, and patient risk factors.
Special populations
AOD-9604 in Special Populations
Pregnancy
No pregnancy safety data exist for AOD-9604. The molecule has not been studied in pregnant humans in published peer-reviewed work, and no FDA pregnancy category or labeling-rule-compliant lactation assessment exists. Use during pregnancy is not supported.
Lactation
No lactation safety data exist for AOD-9604.
Pediatric
No pediatric data exist. AOD-9604 has not been studied in children or adolescents in published peer-reviewed work.
Geriatric
No dedicated geriatric data exist. The Metabolic Pharmaceuticals adult-obesity development program did not produce a published geriatric subgroup analysis.
Renal impairment
No renal-impairment pharmacokinetic data are available for AOD-9604.
Hepatic impairment
No hepatic-impairment pharmacokinetic data are available for AOD-9604.
Evidence quality
AOD-9604 Evidence Quality
The evidence base for AOD-9604 is dominated by a small set of preclinical rodent studies from 2000, 2001 that characterize lipolytic and fat-oxidation effects in obese-rodent models and propose a mechanism partially independent of β3-adrenergic receptor signaling 512. These studies, conducted by the discovery group and the developer (Metabolic Pharmaceuticals), are supportive of the original lipolytic-fragment hypothesis but have not been independently replicated at scale, and the rodent phenotype has not been recapitulated in adequately powered published human pharmacology studies 164.
Human clinical evidence is restricted to the Metabolic Pharmaceuticals phase 1 and phase 2 development program of the 2000s. The pivotal phase 2b adult-obesity trial did not meet its primary weight-loss endpoint, and Metabolic Pharmaceuticals discontinued obesity development 91011. The phase 2b results are not in the indexed peer-reviewed literature; the development outcome is documented through investigational-drug reviews and pipeline analyses of the era 13. The single post-obesity-program preclinical signal is the rabbit osteoarthritis study by Kwon and Park (2015) 16, which has not been followed by human trials 23.
Analytical doping-control literature characterizes detection chemistry and confirms the presence of AOD-9604 in unregulated supply chains, but is not a clinical-efficacy or safety evidence stream 1514. The overall evidence quality for AOD-9604 in any clinical indication is low: a failed phase 2b obesity primary endpoint, no completed phase 3 program, no FDA approval, and FDA Category 2 status on the 503A bulks list 1778.
Preclinical adipocyte and adipose-tissue pharmacology study of synthetic hGH 177, 191 fragment (AOD-9604) in obese-rodent tissues
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Reported lipolytic and anti-lipogenic activity in obese-rodent adipose tissue without engagement of the somatogenic hGH-receptor pathway; foundational discovery report for the molecule 1
Preclinical molecular and cellular pharmacology of the related hGH C-terminal fragment AOD9401
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Characterized lipid-metabolism actions of a structurally related hGH C-terminal fragment in genetically obese rats, supporting the lipolytic-domain hypothesis 2
Preclinical rodent study of oral administration of a synthetic hGH C-terminal fragment
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Reported reductions in adiposity with oral dosing in rodents; oral bioavailability and translational relevance to human dosing remained uncharacterized 3
Structural and conformational analysis of cyclized hGH C-terminal-domain peptides
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Characterized the fold and biological activity of cyclic AOD-9604-related peptides; supports the structural rationale for short-peptide retention of lipolytic activity 4
Preclinical chronic treatment of obese and β3-adrenergic receptor knockout mice with hGH and AOD-9604
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Weight and lipid-metabolism effects of AOD-9604 were partially independent of β3-AR signaling, distinguishing the mechanism from classical sympathomimetic lipolytics 5
Summarized the Metabolic Pharmaceuticals development program, dosing strategy, and early clinical results; this and related reviews are the principal published-literature record of the clinical development history 7
Narrative review of medical management of obesity, including the historical AOD-9604 development program
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Documented discontinuation of AOD-9604 obesity development after the phase 2b weight-loss trial did not meet its primary endpoint; consistent with the contemporaneous reviews by Wilding (2004), Halford (2006), Jensen (2006), and Zieba (2007) 1178910
Preclinical rabbit knee osteoarthritis model with intra-articular AOD-9604, hyaluronic acid, or combination
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Reported histologic and imaging signals consistent with reduced cartilage damage in the combination arm; hypothesis-generating single small-animal study, no human follow-up 16
Analytical-chemistry study characterizing AOD-9604 detection methodology and in vitro metabolic profile for sports doping controls
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Established assay parameters and metabolic-fragment patterns enabling detection of AOD-9604 in human urine; complemented by Orlovius et al 1512. (2013) demonstrating that AOD-9604 does not cross-react with the WADA hGH isoform immunoassay
Analytical case report on identification of AOD-9604 in unknown pharmaceutical preparations seized by Belgian authorities
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Confirmed AOD-9604 presence in illicit injectable peptide preparations sold outside any regulated quality system; representative of the supply chain through which AOD-9604 reaches end-users in the absence of an FDA-approved or 503A-eligible pathway 13
Mechanism detail
Detailed Mechanism of AOD-9604
The 177, 191 region of human growth hormone has been studied as a putative lipolytic fragment since the 1990s. Ogru et al. (2000) used solution-phase conformational analysis to characterize a cyclic anti-obesity peptide derived from the C-terminal domain of hGH, supporting the structural plausibility of a fold-stable short peptide retaining lipolytic activity 4. Ng et al. (2000) reported that an earlier related fragment (AOD9401) exerted molecular and cellular actions on lipid metabolism in Zucker fatty rats 2, and the parallel study on AOD-9604 itself 1 reported lipolytic and anti-lipogenic activity in obese-rodent adipose tissue. Heffernan and colleagues consolidated the pharmacology in vivo with reports of chronic-treatment fat-oxidation and weight-reduction effects in obese and β3-AR knockout mice 56 and an earlier study of an oral synthetic fragment of hGH 3.
The downstream signaling pathways have not been fully resolved. Multiple authors have proposed a lipolytic action mediated independently of the canonical hGH receptor and partially independent of β3-adrenergic receptor signaling 5. No single high-affinity receptor for AOD-9604 has been identified, and the molecular pharmacology remains poorly characterized relative to the depth of mechanistic work available for clinically successful incretin-axis peptides.
Doping-control analytical work has characterized the chemical structure, in vitro metabolism, and detectability of AOD-9604 in human urine and seized illicit-supply preparations 15. These analyses confirm that AOD-9604 does not cross-react with the WADA hGH isoform immunoassay 12, consistent with its short-peptide structure and distinct antigenicity from intact hGH. Vanhee et al. (2014) reported analytical characterization of unknown peptide preparations seized by Belgian authorities and identified AOD-9604 in the illicit supply chain, underscoring the distinction between regulated investigational supply and unregulated international peptide trade 1314.
Pharmacology
AOD-9604 Pharmacokinetics & Pharmacodynamics
Pharmacokinetics
Published human pharmacokinetic data for AOD-9604 are limited. The Metabolic Pharmaceuticals phase 1 program characterized basic PK parameters for subcutaneous administration, but primary PK reports were not published in indexed peer-reviewed journals; the development-era reviews 7 reference the program at a summary level only. Analytical work for doping control 15 characterized in vitro metabolism of AOD-9604, identifying degradation patterns relevant for urinary detection methodology; this is not equivalent to a clinical PK characterization.
Oral administration of a related synthetic hGH C-terminal fragment was studied in rodents 3; oral peptide bioavailability is generally poor and the rodent oral data do not translate to a human oral dosing regimen. No validated human PK parameters (Cmax, Tmax, AUC, half-life, clearance, volume of distribution, bioavailability by route) appear in the indexed peer-reviewed literature.
Pharmacodynamics
Pharmacodynamic effects described for AOD-9604 in the preclinical literature center on lipolysis and fat oxidation in obese-rodent adipose tissue, with reductions in body fat mass over weeks of chronic dosing 156. The reported absence of hGH-receptor-mediated effects (IGF-1 elevation, fasting hyperglycemia, fluid retention) at active lipolytic doses was the design rationale.
Adequately powered human pharmacodynamic data confirming a sustained, clinically meaningful effect on fat oxidation or adiposity have not been published. The phase 2b adult-obesity trial did not meet its primary weight-loss endpoint, which is the principal published-record human pharmacodynamic readout for the molecule and is interpretable as a negative clinical PD signal at the doses and durations tested 711.
Comparative formulations
Comparing AOD-9604 Formulations
There is no FDA-approved comparator formulation for AOD-9604. Within the broader hGH-axis space, AOD-9604 is structurally and pharmacologically distinct from FDA-approved recombinant human growth hormone (somatropin) products, which are full-length 191-amino-acid proteins with established GH-receptor pharmacology, and from growth-hormone secretagogues such as the ghrelin-axis peptides. Unlike incretin-axis peptides (semaglutide, tirzepatide), which have completed phase 3 weight-management programs and have FDA-approved branded products, AOD-9604 did not advance beyond phase 2b obesity development 711.
Storage
AOD-9604 Storage and Handling
There is no FDA-approved storage labeling for AOD-9604 because there is no FDA-approved product. Historical investigational supply was handled per Metabolic Pharmaceuticals' phase 1/2 trial protocols. RonanRx does not store or dispense AOD-9604.
RonanRx operations
AOD-9604 Compounding & Operations
503A compounding
Physicians may submit patient-specific prescription requests for pharmacy review. For AOD-9604, certain preparations may be available now when clinically appropriate, lawfully prescribed, and approved by the dispensing pharmacy. Availability is determined case by case and may depend on patient-specific documentation, ingredient status, source qualification, formulation feasibility, state requirements, and pharmacist judgment. The review starts with the evidence constraint: The evidence base for AOD-9604 includes early obesity-focused development and growth-hormone-fragment pharmacology, but it did not become an FDA-approved metabolic drug. Published evidence does not support broad consumer weight-loss claims.
This ingredient is part of an evolving FDA review process. RonanRx is monitoring FDA's PCAC process and any subsequent agency action. This ingredient is part of an evolving FDA review process for peptide-related bulk substances used in compounding. Availability may change after FDA review, PCAC discussion, final agency action, or state-board guidance. For AOD-9604, RonanRx ties that monitoring to the evidence limits described above and to any patient-specific documentation submitted by the prescriber.
Valid patient-specific prescription required. Supporting clinical rationale may be requested. Compounded medications are not FDA-approved. No consumer self-ordering, no office stock, no bulk dispensing. Requests for AOD-9604 are reviewed before any preparation is made or released. A patient-specific prescription request is not a weight-loss product listing. It must be tied to clinician documentation, pharmacy review, ingredient sourcing, and formulation feasibility before any dispensing decision.
Pharmacist review
For AOD-9604, the pharmacist review starts before any preparation is made. Valid patient-specific prescription required. Supporting clinical rationale may be requested. The pharmacist reviews ingredient status, sourcing, formulation feasibility, state requirements, patient-specific documentation, and whether dispensing is appropriate case by case.
Quality and traceability
If a AOD-9604 preparation is approved after pharmacy review, RonanRx applies source documentation, formulation records, lot traceability, release checks, and storage controls appropriate to the actual dosage form. Research-use vial storage practices do not substitute for pharmacy-assigned storage, beyond-use dating, sterility controls when applicable, or recallable batch records. The patient-specific framework and quality controls are documented in the cited compounding references 2019.
Cold chain
If a AOD-9604 preparation is approved after pharmacy review, RonanRx applies source documentation, formulation records, lot traceability, release checks, and storage controls appropriate to the actual dosage form. Research-use vial storage practices do not substitute for pharmacy-assigned storage, beyond-use dating, sterility controls when applicable, or recallable batch records.
FAQ
Frequently Asked Questions About AOD-9604
Can physicians request AOD-9604 through RonanRx?
Physicians may submit patient-specific prescription requests for pharmacy review. Certain preparations may be available now when clinically appropriate, lawfully prescribed, and approved by the dispensing pharmacy. Availability is determined case by case. Compounded medications are not FDA-approved, and no consumer self-ordering, office stock, or bulk dispensing is offered.1718
What is AOD-9604?
AOD-9604 is a synthetic 16-amino-acid peptide based on residues 177, 191 of human growth hormone 3. It was designed in the 1990s by the Australian biotechnology company Metabolic Pharmaceuticals as a candidate anti-obesity therapeutic that would retain the lipolytic (fat-burning) effects of growth hormone without the systemic GH/IGF-1 effects 17.
Did AOD-9604 work for weight loss?
The pivotal phase 2b adult-obesity weight-loss trial run by Metabolic Pharmaceuticals did not meet its primary weight-loss endpoint, and the company discontinued obesity development for AOD-9604 in 2007 789. There is no completed phase 3 obesity program 11. The result of the phase 2b study is documented through subsequent investigational-drug pipeline reviews; the primary trial was not published in the indexed peer-reviewed literature.
Is AOD-9604 FDA-approved?
No. AOD-9604 has no FDA-approved indication or branded product. It has not been the subject of an approved NDA, ANDA, BLA, or OTC monograph. It is on FDA's 503A bulk drug substances Category 2 list, which means the FDA has identified significant safety questions and the substance is not eligible for routine patient-specific compounding under section 503A 1718.
Why is AOD-9604 still discussed if obesity development failed?
Two reasons. First, a single 2015 rabbit-osteoarthritis preclinical study suggested a possible cartilage-protective signal at the intra-articular route, which has occasionally been cited in marketing materials for unregulated peptide suppliers; this is a single small-animal study and has not been followed by human trials 16. Second, AOD-9604 is encountered by sports anti-doping laboratories in seized illicit peptide preparations, which has driven analytical-method development 13. Neither line of work establishes a clinical role for AOD-9604 151214.
Is the Australian TGA listing the same as US approval?
No. Australian regulatory notifications addressing AOD-9604 in cosmetic or dietary ingredient contexts are jurisdiction-specific to Australia and do not represent therapeutic-goods registration as a drug for any indication. They have no bearing on US drug status, which is governed by the FDA 17. AOD-9604 has no FDA approval and is on the FDA 503A bulks Category 2 list 13.
What should clinicians do if a patient is already using AOD-9604?
For AOD-9604, physicians may submit patient-specific prescription requests for pharmacy review. Availability is determined case by case, and supporting clinical rationale may be requested.131517
Clinician resource
Download the AOD-9604 Clinical Monograph (PDF)
The full white paper covers every section on this page plus chemical identity, evidence grading, indication-by-indication summaries, research gaps, and reference appendix. Suitable for sharing with prescribing doctors and pharmacist reviewers.
[ng2000a] Ng FM, Sun J, Sharma L, Libinaka R, Jiang WJ, Gianello R. Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone. Hormone Research. 2000. PMID 11146367. (accessed 2026-05-11)
[ng2000b] Ng FM, Jiang WJ, Gianello R, Pitt S, Roupas P. Molecular and cellular actions of a structural domain of human growth hormone (AOD9401) on lipid metabolism in Zucker fatty rats. Journal of Molecular Endocrinology. 2000. PMID 11116208. (accessed 2026-05-11)
[heffernan2000] Heffernan MA, Jiang WJ, Thorburn AW, Ng FM. Effects of oral administration of a synthetic fragment of human growth hormone on lipid metabolism. American Journal of Physiology. Endocrinology and Metabolism. 2000. PMID 10950816. (accessed 2026-05-11)
[ogru2000] Ogru E, Wilson JC, Heffernan M, Jiang WJ, Chalmers DK, Libinaki R, Ng F. The conformational and biological analysis of a cyclic anti-obesity peptide from the C-terminal domain of human growth hormone. The Journal of Peptide Research. 2000. PMID 11152298. (accessed 2026-05-11)
[heffernan2001a] Heffernan M, Summers RJ, Thorburn A, Ogru E, Gianello R, Jiang WJ, Ng FM. The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following chronic treatment in obese mice and beta(3)-AR knock-out mice. Endocrinology. 2001. PMID 11713213. (accessed 2026-05-11)
[heffernan2001b] Heffernan MA, Thorburn AW, Fam B, Summers R, Conway-Campbell B, Waters MJ, Ng FM. Increase of fat oxidation and weight loss in obese mice caused by chronic treatment with human growth hormone or a modified C-terminal fragment. International Journal of Obesity and Related Metabolic Disorders. 2001. PMID 11673763. (accessed 2026-05-11)
[wilding2004] Wilding J. AOD-9604 Metabolic. Current Opinion in Investigational Drugs. 2004. PMID 15134286. (accessed 2026-05-11)
[halford2006] Halford JC. Obesity drugs in clinical development. Current Opinion in Investigational Drugs. 2006. PMID 16625817. (accessed 2026-05-11)
[jensen2006] Jensen MD. Potential role of new therapies in modifying cardiovascular risk in overweight patients with metabolic risk factors. Obesity. 2006. PMID 16931496. (accessed 2026-05-11)
[zieba2007] Zieba R. [Obesity: a review of currently used antiobesity drugs and new compounds in clinical development].. Postepy Higieny i Medycyny Doswiadczalnej. 2007. PMID 17971763. (accessed 2026-05-11)
[khan2012] Khan A, Raza S, Khan Y, Aksoy T, Khan M, Weinberger Y. Current updates in the medical management of obesity. Recent Patents on Endocrine, Metabolic & Immune Drug Discovery. 2012. PMID 22435392. (accessed 2026-05-11)
[orlovius2013] Orlovius AK, Thomas A, Schänzer W, Thevis M. AOD-9604 does not influence the WADA hGH isoform immunoassay. Drug Testing and Analysis. 2013. PMID 24124033. (accessed 2026-05-11)
[vanhee2014] Vanhee C, Moens G, Deconinck E, De Beer JO. Identification and characterization of peptide drugs in unknown pharmaceutical preparations seized by the Belgian authorities: case report on AOD9604. Drug Testing and Analysis. 2014. PMID 24976118. (accessed 2026-05-11)
[thevis2014] Thevis M, Schänzer W. Analytical approaches for the detection of emerging therapeutics and non-approved drugs in human doping controls. Journal of Pharmaceutical and Biomedical Analysis. 2014. PMID 24906629. (accessed 2026-05-11)
[cox2015] Cox HD, Smeal SJ, Hughes CM, Cox JE, Eichner D. Detection and in vitro metabolism of AOD9604. Drug Testing and Analysis. 2015. PMID 25208511. (accessed 2026-05-11)
[kwon2015] Kwon DR, Park GY. Effect of Intra-articular Injection of AOD9604 with or without Hyaluronic Acid in Rabbit Osteoarthritis Model. Annals of Clinical and Laboratory Science. 2015. PMID 26275694. (accessed 2026-05-11)
[usp_797] United States Pharmacopeia. USP General Chapter <797> Pharmaceutical Compounding — Sterile Preparations. USP Compounding Compendium. 2023. https://www.usp.org/compounding/general-chapter-797 (accessed 2026-05-11)
[usp_795] United States Pharmacopeia. USP General Chapter <795> Pharmaceutical Compounding — Nonsterile Preparations. USP Compounding Compendium. 2023. https://www.usp.org/compounding/general-chapter-795 (accessed 2026-05-11)
How to access
How to Access AOD-9604
Physicians may submit patient-specific prescription requests for AOD-9604 for pharmacy review. Availability is determined case by case, and RonanRx is monitoring FDA's PCAC process and any subsequent agency action.
For doctors
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