Is AOD-9604 a Peptide? Structure, Origin and Research Status

Yes. AOD-9604 is a peptide, and more precisely a synthetic hexadecapeptide: a chain of 16 amino acids built to mimic one small region of human growth hormone (hGH). It is not a hormone, a steroid or a small-molecule drug. It is also not an FDA-approved medicine, which matters for anyone handling it in a laboratory.

This guide explains what makes AOD-9604 a peptide, where its sequence comes from, what the human trials found, how regulators treat it, and what a researcher should check before ordering any lot of it. Everything here is for educational and laboratory-research context only. It is not medical advice and makes no claim that the compound treats any condition.

TL;DR

• AOD-9604 is a synthetic peptide of 16 amino acids, based on the C-terminal region of human growth hormone (residues 177 to 191) plus one added tyrosine.
• It was developed as an obesity drug candidate. Early human trials reported good tolerability, but a larger 24-week trial missed its weight-loss endpoint and development stopped in 2007.
• It is not FDA-approved for human use, and the FDA has flagged safety concerns about compounded versions. It is also on the WADA prohibited list.
• For laboratory work, the practical test is a lot-specific certificate of analysis (COA) covering purity, mass accuracy, endotoxins, sterility and heavy metals.

What makes AOD-9604 a peptide

A peptide is a short chain of amino acids joined by peptide bonds. Proteins are the same thing at greater length, and the line between them is conventional rather than sharp. A chain of 16 residues sits comfortably on the peptide side.

AOD-9604 fits that definition exactly. According to the published safety and tolerability literature, it is a fragment of the C-terminus of hGH (amino acids 177 to 191) with an extra tyrosine residue added at the N-terminal end to improve stability. The sequence is written as YLRIVQCRSVEGSCGF, and the molecule is cyclized by a disulfide bridge between two cysteine residues.

The name is a leftover of its origin: AOD stands for “anti-obesity drug,” and 9604 was the internal compound number. It is made by solid-phase peptide synthesis, the same laboratory method used for most research peptides, rather than being extracted from any biological source (Moré et al., 2014).

Key chemical facts

The molecular weight is useful beyond trivia. Mass accuracy testing compares the measured mass of a vial’s contents with the expected value, so a researcher who knows the target figure can read a COA critically.

Is it a hormone, a fragment or a drug?

These three words get mixed up in search results, so it helps to separate them.

Not a hormone. Full-length hGH is a roughly 191-amino-acid protein hormone with broad effects on growth, metabolism and blood sugar. AOD-9604 contains only a short slice of that sequence. The research background describes it as retaining the lipolytic (fat-breakdown) signal studied in the parent molecule while not acting through IGF-1 or affecting carbohydrate metabolism in the same way as full-length hGH.

A fragment, yes. It is a modified fragment, which is the most accurate short description. Some sources describe the underlying region as residues 176 to 191, and the difference is a matter of numbering convention for the added tyrosine. The research literature cited above uses 177 to 191 plus tyrosine.

A drug candidate, not an approved drug. It was designed in the context of drug development, and that history is why it has a clinical record at all. But the clinical record ended without approval, as the next section explains.

What the human trials showed

Most peptides sold for research have little or no human trial history. AOD-9604 is an unusual case because it has one, and it is worth reading accurately instead of through marketing summaries.

According to the Journal of Endocrinology and Metabolism review, six randomized, double-blind, placebo-controlled trials ran between 2001 and 2006, enrolling 893 healthy or obese adults. The results generally indicated the peptide was safe and well tolerated, with no negative effect on serum IGF-1 or carbohydrate metabolism, in contrast with full-length hGH.

The efficacy side is less encouraging. The same source reports that one trial of 536 subjects over 24 weeks did not meet its primary endpoint for significant weight loss, and Metabolic Pharmaceuticals discontinued development as an obesity drug in 2007. The failure was one of efficacy rather than a safety signal.

Earlier animal work is where the enthusiasm came from. A 2000 study in obese Zucker rats examined the metabolic actions of the lipolytic domain of hGH. Rodent data is a starting point for hypotheses, not evidence of what happens in people.

So the honest summary is this: AOD-9604 is a well-characterized peptide with a reasonable early safety record and a disappointing efficacy result. That makes it a useful tool for studying lipid-metabolism pathways, and not a validated treatment for anything.

Regulatory status in the United States

Why AOD-9604 is not FDA-approved

FDA approval of a new drug requires a very large financial investment, multi-phase clinical trials and a commercial sponsor willing to carry both. When a compound is hard to patent, or the lead developer stops after a missed endpoint, the money rarely follows, even where scientific interest continues. AOD-9604 sits in that situation: the sponsor ended development in 2007, and no company has taken it through approval since.

The agency has also looked at it directly. In the FDA’s list of bulk drug substances that may present significant safety risks, AOD-9604 appears with concerns about immunogenicity for certain routes of administration and about peptide-related impurities. The agency noted there was not enough safety information to say whether compounded versions are safe for people.

The briefing document for the December 4, 2024 Pharmacy Compounding Advisory Committee meeting goes into more detail on the same nomination. Its recurring themes are the difficulty of characterizing peptides and ensuring consistency, sterility and purity. Those are manufacturing and testing questions, and they are the reason documentation matters so much in this field.

Anti-doping status

AOD-9604 is also treated as a prohibited substance in sport. A paper on its detection and in vitro metabolism in the journal Drug Testing and Analysis was written in that anti-doping context. Anyone subject to athletic testing should treat it as off limits.

What this means in practice

AOD-9604 is a research-grade compound. Laboratory-use-only handling is the correct frame, not a technicality. If your questions are about human use, dosing for a person or treating a condition, those belong with a licensed physician, not a supplier or a search result. For the wider picture of how research-use-only labeling works, see our explainer on why some peptides are sold for research use only.

How it differs from other weight-related peptides

People often ask whether AOD-9604 belongs in the same family as the GLP-1 medicines. It does not. Those approved drugs work on incretin receptors, and their labels, doses and trial programs are an entirely different category. A clinician’s overview such as this comparison of Wegovy and Ozempic shows how much structure approved products carry: defined strengths, indications and prescriber oversight. AOD-9604 has none of that, because it never completed the pathway.

The contrast is worth keeping clear:

• Mechanism class. AOD-9604 is a growth hormone fragment studied for lipolysis. The GLP-1 class are receptor agonists.
• Evidence base. AOD-9604 has six early trials and one missed primary endpoint. Approved agents have large Phase 3 programs.
• Status. AOD-9604 is not approved. Approved agents carry FDA labels for specific indications.

If you are researching the receptor-agonist side, our pages on semaglutide and its different FDA labels and on verifying COAs for semaglutide, tirzepatide and retatrutide cover those compounds separately.

Why sourcing and testing matter for a peptide like this

Because AOD-9604 is a modified, cyclized peptide, quality is not guaranteed by the name on a label. Two vials can carry the same name and differ in purity, in truncated sequences, in contamination or in fill amount.

The research background also notes that AOD-9604 can be prone to aggregation and self-association, common in complex peptides and a source of impurities. That is why analytical testing is the center of responsible sourcing, not an add-on.

What a useful COA should show

1. Purity. Usually reported from HPLC, with the chromatogram or a clear percentage.
2. Mass accuracy. Measured mass against the expected value for the documented sequence (YLRIVQCRSVEGSCGF).
3. Endotoxin result. Relevant to any work involving cells or biological systems.
4. Sterility. Confirms the lot was not microbially contaminated.
5. Heavy metals. Screens for residues from synthesis and handling.
6. Lot or batch number. It should match the number printed on your vial, so the document describes the material you actually hold.

A generic COA reused across batches proves nothing. The test is whether the document is lot-specific and independently generated.

Our perspective

We get this question often, and the short answer is easy. The harder part is what follows it: people assume that because a compound has a trial history and a recognizable name, it is a settled, approved product. It is neither.

At Peppy&Me, we treat AOD-9604 the way we treat everything in our catalog: as a research compound for laboratory use only, sold to authorized adults aged 21 and over. Every lot we carry is third-party tested for purity, mass accuracy, endotoxins, sterility and heavy metals, with traceable lot and batch numbers from manufacturer to warehouse, and the COA is accessible by QR code.

We also think the education matters as much as the vial. Our peptide glossary explains handling and terminology, and our built-in calculator helps researchers prepare reconstitution math accurately. We would rather a customer understand that AOD-9604 missed its efficacy endpoint than buy it on a hunch. Good research starts from the actual record, including the parts that are disappointing.

— Peppy&Me

Ordering AOD-9604 for laboratory research

If your work calls for this compound, you can review the AOD-9604 research peptide listing with its lot documentation, or browse the full research compounds catalog for related peptides, amino acids and blended research materials. Orders placed before 2 PM ship the same day within the U.S., and real-time support is available if you need help reading a COA.

Membership is private and account-based, so you can track orders and keep your documentation in one place. Products are for laboratory research only, not for human consumption.

Frequently asked questions

Is AOD-9604 the same as human growth hormone?

No. AOD-9604 is a 16-amino-acid synthetic fragment based on residues 177 to 191 of hGH, while full-length hGH is a much larger protein hormone. Published work describes it as not acting through IGF-1 in the way full-length hGH does. The two are different molecules with different properties.

Is AOD-9604 FDA-approved?

No. It has not been approved by the FDA for human use, and the agency has published safety concerns about compounded forms, including immunogenicity and impurity risks. Any question about human use should go to a licensed physician.

Does AOD-9604 work for weight loss?

The clinical record does not support that claim. In the reported program, a 24-week trial of 536 subjects did not meet its primary weight-loss endpoint, and development as an obesity drug ended in 2007. It remains a research tool for studying fat metabolism pathways, not a proven treatment.

What is AOD-9604 made of?

It is made of 16 amino acids with the sequence YLRIVQCRSVEGSCGF, a cyclized chain produced by solid-phase peptide synthesis. The first residue, tyrosine, is an addition to the native hGH fragment that improves stability.

Sources

• Safety and Tolerability of the Hexadecapeptide AOD9604 in Humans, Journal of Endocrinology and Metabolism
• Safety and Metabolism of AOD9604, a Novel Nutraceutical Ingredient, Journal of Endocrinology and Metabolism
• FDA: Certain Bulk Drug Substances for Use in Compounding That May Present Significant Safety Risks
• FDA: December 4, 2024 Pharmacy Compounding Advisory Committee Meeting briefing document
• Detection and in vitro metabolism of AOD9604, PubMed
• AOD-9604 (acetate), PubChem
• Metabolic studies of a synthetic lipolytic domain of hGH, University of Queensland eSpace

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