AOD-9604

What it is

AOD-9604 is a synthetic hexadecapeptide: 15 amino acids from the C-terminal region of human growth hormone (residues 177–191) plus a tyrosine at the N-terminal end [1]. It was developed and patented by Metabolic Pharmaceuticals Ltd in Australia in the late 1990s as an obesity treatment, on the idea that this fragment carries the fat-reducing activity of growth hormone without its effects on IGF-1 or glucose metabolism [1][3]. Its sequence is YLRIVQCRSVEGSCGF [3]. There is no FDA-approved drug containing AOD-9604 (free base) or AOD-9604 acetate, and no USP or NF monograph [1]. Nominations proposed compounded products for subcutaneous injection, oral capsules and topical cream, but FDA found no human data for the subcutaneous or transdermal routes [1]. The only human studies used intravenous or oral dosing, so an injected compounded product is outside anything that has been tested in people [1].

How it works

The proposed mechanism is lipolytic and anti-lipogenic activity inherited from the C-terminus of growth hormone, but FDA’s reviewers concluded that “the molecular targets for AOD-9604 have not been identified and its mechanisms of action remain unknown” [1]. In the human trials, AOD-9604 had no effect on serum IGF-1, which the sponsor’s authors took as confirmation that it does not act through the growth-hormone/IGF-1 axis [3]. Oral glucose tolerance testing showed no deterioration in glucose handling, in contrast to full-length growth hormone [3]. FDA also noted that statistical analyses in the nonclinical studies were not corrected for multiple comparisons, leaving the pharmacological findings uncertain [1]. In pigs, the peptide was orally absorbed with peak plasma levels about 60 minutes after dosing, but the extent of oral bioavailability is unclear even in animals [1].

What the evidence shows

Between 2001 and 2006 Metabolic Pharmaceuticals ran six randomized, double-blind, placebo-controlled trials with 893 participants, two intravenous single-dose studies and four oral studies, in healthy or obese adults [3]. The largest, METAOD006 (the “OPTIONS” study), randomized 502 adults with obesity to 0.25, 0.5 or 1 mg oral AOD-9604 daily or placebo for 24 weeks alongside a dietitian-supervised diet and exercise program [1][3]. It found no significant difference from placebo in weight loss at the 12-week primary endpoint, and on February 21, 2007 the company announced that the results “do not support the commercial viability of the drug as a treatment for obesity” and terminated development [1]. FDA found that in most studies AOD-9604 failed to show benefit versus placebo, that the published information is limited to short summaries lacking methodological detail, and that clinicaltrials.gov lists no AOD-9604 studies [1]. Obesity practice guidelines do not mention it [1].

Regulatory status

AOD-9604 is not an FDA-approved drug and is not a component of any approved product [1]. In September 2023 FDA placed it in 503A Category 2, the interim list of nominated substances FDA considers to raise significant safety risks, citing immunogenicity, impurity and characterization concerns, limited safety data and serious adverse events of unclear causality [4][5][7]. On September 20, 2024 FDA announced its removal from Category 2, effective September 27, 2024, because the nominators withdrew the nominations [5]. FDA then evaluated it on its own initiative and, for the December 4, 2024 Pharmacy Compounding Advisory Committee meeting, proposed that neither the free base nor the acetate be added to the 503A bulks list [1]. The committee voted 0 yes, 12 no, 0 abstain on adding them [2]. AOD-9604 does not appear in any category on FDA’s May 14, 2026 list of nominated 503A substances, and we found no FDA rule listing it (as of Sep 24 2026) [6].

Half-life and what it means for a level curve

STACK has no reference half-life for this compound because no human value has been published; you can enter your own estimate. FDA’s reviewers wrote that they “did not identify clinical studies in humans assessing pharmacokinetics or pharmacodynamics of AOD-9604 via any route” [1]. The only measured value is in animals: after an intravenous bolus in adult female pigs, the half-life was very short, about 3 minutes, with a mean Cmax of 1,944 ng/mL [1]. After oral dosing in pigs, plasma levels peaked at roughly 60 minutes [1]. If a 3-minute half-life held in people, the peptide would be essentially gone from blood within about 15 minutes, since a level reaches ~97% of steady state after about 5 half-lives with regular dosing; each dose would look like a brief spike. STACK’s curve is an estimate from this published half-life, not a blood level. Because this is pig data, STACK does not use it as a default.

Reported side effects

Human safety data come from the six sponsor trials, whose authors were employees or consultants of Metabolic Pharmaceuticals [1]. They reported a safety and tolerability profile “indistinguishable from placebo,” no anti-AOD-9604 antibodies, and no change in IGF-1 or glucose tolerance [3]. The most common adverse events were headache, diarrhea, flatulence, nasopharyngitis and back pain; in the intravenous studies, one severe chest-tightness event and mild-to-moderate euphoria in 5 of 23 subjects were judged possibly related [3]. In the 12-week oral study, five serious events were cancers or a lipoma (basal cell carcinoma, squamous cell carcinoma, melanoma, breast cancer), which the investigators judged unrelated [3]. FDA counted these as serious adverse events of unclear relatedness, noted rat bone-health and monkey liver signals and equivocal genotoxicity results, and found no FAERS reports through January 7, 2024, while cautioning that absence of reports does not mean safety [1]. Nothing is known about injected use in humans [1].

Storage and handling

There is no FDA-approved AOD-9604 product and therefore no FDA label, so the compounding pharmacy’s label governs storage [1]. FDA notes that the safety of a compounded AOD-9604 product “can be negatively impacted by various factors that include the product formulation, peptide concentration, and conditions of storage favoring the generation of product-related impurities” [1]. In the intravenous trials the peptide was supplied lyophilized and reconstituted with sterile water before use; the oral studies used capsules or tablets [3]. Follow the pharmacy’s instructions on refrigeration, protection from light and the discard date after first puncture, and do not freeze a reconstituted vial unless told to. The STACK reconstitution calculator does the volume math from the vial strength and diluent you enter; it does not suggest a dose. Ask the dispensing pharmacist when in doubt.

What STACK tracks for it

STACK logs each AOD-9604 dose exactly as your prescriber wrote it, in mg or mcg, with the route (injection or oral) and, for injections, the site. Because there is no published human half-life, the estimated level curve stays off until you enter your own estimate, and STACK labels it as yours. Since the compound was studied for obesity, STACK lets you track weight and waist measurements over time alongside your logged doses, so you and your prescriber can see what actually changed [3]. You can record side effects such as headache, digestive upset or injection-site reactions, and STACK keeps vial inventory so you know when a refill is due and records the schedule your prescriber gave you. It also shows the regulatory status above, including the 0–12 committee vote, so the context is never hidden [2].

The reference half-life in STACK

STACK ships AOD-9604 without a default half-life: No human value; ~3 min after IV bolus in pigs. You enter your own estimate before a curve is drawn. Measured in: none — FDA found no human pharmacokinetic study; adult female pigs only.

Estimate only. Modelled from the published half-life you selected and the doses you logged — not a measured blood level. Do not use it to make medication decisions.

Free tools for AOD-9604

Read next

Sources

Every URL below was fetched and checked on 2026-09-24. Bracketed numbers in the text link here.

1. FDAFDA Briefing Document, Pharmacy Compounding Advisory Committee Meeting, December 4, 2024 (AOD-9604, CJC-1295, thymosin alpha-1)
2. FDAFinal Summary Minutes of the Pharmacy Compounding Advisory Committee Meeting, December 4, 2024
3. TrialSafety and Tolerability of the Hexadecapeptide AOD9604 in Humans (Stier, Vos, Kenley; J Endocrinol Metab 2013)
4. FDACertain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks (FDA)
5. OtherFDA Removes Certain Peptide Bulk Drug Substances From Category 2 Of Interim 503A Bulks List And Sets Dates For PCAC Review (Reed Smith via Mondaq, Oct 4 2024)
6. FDABulk Drug Substances Nominated for Use in Compounding Under Section 503A (FDA, updated May 14, 2026)
7. OtherFDA's Pep(tide) Rally! What Compounders and Industry Need to Know (Hyman, Phelps & McNamara FDA Law Blog, Apr 2026)