AOD-9604 Research Guide (2026): The Fat Metabolism Fragment

AOD-9604 occupies an unusual corner of the research peptide catalog. It isn't one of the high-volume compounds like BPC-157 or semaglutide, but it has a persistent following among lipid metabolism researchers because it isolates one specific function of human growth hormone — the lipolytic fragment — without dragging along the growth-promoting half of the molecule. That makes it a useful tool compound for studying fat metabolism in preclinical models without simultaneously activating the IGF-1 axis.

This 2026 guide collects what an independent reviewer should know before sourcing AOD-9604 for laboratory work: the underlying chemistry, what the research has actually examined, how it differs from full hGH, and what a research-grade supplier should look like. Everything below is written for laboratory research use only — no human supplementation claims, no dosing guidance.

What AOD-9604 is

AOD-9604 — short for "Anti-Obesity Drug 9604" — is a synthetic peptide consisting of amino acids 176 through 191 of the human growth hormone sequence, with an added tyrosine residue at the N-terminus to aid stability. The full hGH molecule is 191 amino acids long. AOD-9604 is a 16-amino-acid fragment, plus the tyrosine modification, which gives it a final length of 17 residues.

The peptide was developed in the 1990s by Professor Frank Ng at Monash University in Australia, working with Metabolic Pharmaceuticals (later Calzada Limited). The premise was straightforward: prior research had suggested that the lipolytic activity of growth hormone — its ability to mobilise stored fat for energy in cellular models — resided in the C-terminal portion of the hGH molecule, separable from the growth-promoting activity localised elsewhere in the protein. AOD-9604 was synthesised as a way to isolate that fragment.

In preclinical models, the peptide showed lipolytic activity in adipose tissue preparations without measurable IGF-1 stimulation. That separation of function is what makes it interesting as a research tool — and what distinguishes it from administering full recombinant hGH.

The science: residues 176-191 of hGH

Human growth hormone is a 22 kDa protein with multiple functional domains. The N-terminal region is associated with growth-promoting activity mediated primarily through hepatic IGF-1 secretion. The C-terminal region — specifically residues 177 to 191 in the native sequence — has been associated in animal model work with effects on lipid metabolism, including stimulation of lipolysis and inhibition of lipogenesis in isolated adipocyte preparations.

AOD-9604 replicates that C-terminal fragment. The added N-terminal tyrosine isn't part of the native hGH sequence; it was incorporated during synthesis to improve metabolic stability and provide a handle for radio-iodination in early pharmacokinetic studies.

Mechanistically, the research literature has examined whether AOD-9604 acts through beta-3 adrenergic receptor pathways in adipose tissue, though the exact mechanism remains an active area of investigation. Importantly for researchers choosing between full hGH and the fragment: AOD-9604 has not shown measurable effects on growth plate cartilage, IGF-1 levels, or insulin sensitivity in the animal models where it has been characterised. That clean separation is the selling point of the fragment.

What the research has examined

The published literature on AOD-9604 spans roughly three areas. None of what follows is a health claim for human use — it's a summary of laboratory and animal model investigations and the small clinical trial record.

• Lipolysis in adipocyte preparations. In vitro studies on isolated adipose tissue have examined whether AOD-9604 stimulates the breakdown of stored triglycerides into free fatty acids and glycerol. Several papers in the early 2000s reported dose-dependent lipolytic activity in mouse and rat adipocyte cultures.
• Animal model fat-burning studies. Obese mouse models (ob/ob and diet-induced obesity strains) have been used to examine whether systemic administration of AOD-9604 affects body composition over multi-week protocols. Reported endpoints included adipose tissue mass, plasma free fatty acid concentrations, and respiratory exchange ratio.
• Clinical trial history. Metabolic Pharmaceuticals advanced AOD-9604 through several Phase II human trials in the mid-2000s, primarily examining body weight endpoints in adult populations. The program did not advance to Phase III approval, and the compound was eventually de-prioritised by the sponsor. The clinical data is publicly available in trial registries.
• Cartilage and joint research. A secondary research line examined whether AOD-9604 has activity in cartilage cell preparations, motivated by observations of growth hormone effects on chondrocytes. This work is smaller in volume than the lipid metabolism literature.

Framing matters here. The lipolytic activity reported in research models is exactly that — a research finding in preclinical models. AOD-9604 is not an approved therapy for any human indication, and the clinical trial record did not produce a registration package.

AOD-9604 vs full hGH

This is the single most important conceptual distinction for researchers deciding which compound fits their protocol.

Property	Full hGH (Somatropin)	AOD-9604
Length	191 amino acids	17 amino acids (16 hGH residues + N-terminal Tyr)
Molecular weight	~22 kDa	~1.8 kDa
Growth-promoting activity	Yes (via IGF-1)	Not observed in preclinical models
Lipolytic activity	Yes	Yes
IGF-1 stimulation	Yes	Not observed
Effect on growth plate	Yes	Not observed
Receptor binding	hGH receptor	Mechanism still under investigation
Regulatory status (US)	Prescription drug (somatropin)	Research compound, not FDA-approved
Synthesis	Recombinant (E. coli or mammalian)	Solid-phase peptide synthesis

The practical takeaway: if a research protocol is specifically designed to study lipid metabolism without confounding effects from growth-axis activation, the fragment is a more selective tool than administering full hGH. If a protocol requires the full spectrum of growth hormone activity, the fragment isn't a substitute for somatropin — they aren't equivalent compounds.

Sourcing landscape in 2026

AOD-9604 is a niche compound in the research peptide market. It doesn't move the volume that BPC-157, TB-500, or the GLP-1 analogues do, which means fewer suppliers carry it and stock can be irregular. Three patterns are worth flagging for buyers.

Carrier scarcity. Of the eight US research compound suppliers we routinely track, only five carry AOD-9604 as a regular catalog item. The other three list it intermittently or have moved it to a special-order tier. Smaller offshore suppliers list it more often but with weaker documentation.

COA quality varies. Because volume is lower, some suppliers don't run batch-specific HPLC on AOD-9604 the way they do on their flagship compounds. A generic "typical purity ≥98%" line on a product page isn't the same as a batch-stamped certificate of analysis with a chromatogram. The 17-residue length and tyrosine modification mean the peak structure on HPLC is distinctive — a real COA shows it.

Counterfeiting risk. Because AOD-9604 is more expensive per milligram than common peptides and the buyer base is small, the temptation to substitute a cheaper compound (or to dilute) is real. Without third-party HPLC, the buyer has no way to verify what's in the vial.

The supplier landscape is shifting in 2026 toward suppliers that publish per-batch testing for every catalog item, including the lower-volume compounds. ROEHN Research is one of the US suppliers that does carry AOD-9604 with batch-stamped COAs.

Quality markers for AOD-9604

The checklist for research-grade AOD-9604 isn't dramatically different from any other short synthetic peptide, but two items deserve emphasis.

Marker	What to look for
HPLC purity	≥98% by reversed-phase HPLC, batch-specific
Mass spec confirmation	Theoretical mass ~1815 Da; supplier should publish observed mass
Third-party testing	Janoshik, MZ Biolabs, or equivalent independent lab
Bacterial endotoxin	Tested by LAL assay where applicable
Lyophilisation quality	White, uniform powder; no clumping or discolouration
Sealing	Vials sealed under inert gas; intact rubber stoppers
Cold chain	Refrigerated storage during transit
Documentation	Batch number, synthesis date, expiry, storage instructions

The mass spec point is worth dwelling on. AOD-9604 has a distinctive molecular mass of approximately 1815 daltons (the exact value depends on the salt form). A supplier that publishes mass spec data showing a clean peak at the correct mass — without significant fragmentation peaks or unexpected adducts — has done the work to confirm identity. A supplier that publishes only "purity by HPLC" without mass confirmation has done less.

Pricing context

AOD-9604 pricing in 2026 sits in a higher band than common peptides because synthesis is more expensive per milligram and volume is lower. Typical US supplier pricing for research-grade material:

Vial size	Typical price range (mid-2026)
2mg	$35-$55
5mg	$70-$100
10mg	$130-$180
5x 5mg pack	$300-$400

Pricing below the lower end of these ranges — particularly anything below $25 for a 2mg vial — is a flag. The arithmetic of synthesis, purification, lyophilisation, vialing under inert gas, COA testing, and cold-chain shipping doesn't support those prices for a fresh, fully tested batch. The supplier is either selling old inventory, skipping QC, or selling something other than what the label says.

Storage and handling

AOD-9604 is a small synthetic peptide and is more stable than NAD+ or large polypeptides, but it still benefits from proper handling.

• Lyophilised storage. Refrigerated at 2-8°C, lyophilised AOD-9604 is stable for at least 24 months when sealed properly. Long-term storage (>2 years) is better at -20°C or -80°C.
• Reconstituted storage. Once reconstituted in bacteriostatic water or sterile saline, AOD-9604 solutions are typically stable for 30-60 days refrigerated. Avoid freeze-thaw cycles, which degrade peptide solutions faster than continuous refrigeration.
• Light sensitivity. The tyrosine residue at the N-terminus makes the peptide modestly light-sensitive. Amber vials or storage in a dark refrigerator is standard practice.
• Reconstitution. Bacteriostatic water is the standard reconstitution medium for stability. Sterile water without preservative is acceptable for short-term protocols.

These are general handling parameters consistent with the published stability data — not protocol guidance for any specific experimental application.

Bottom line

AOD-9604 is a useful tool compound for researchers who specifically want to study the lipolytic fragment of human growth hormone without confounding effects from the growth-promoting half of the molecule. It is not a replacement for somatropin in protocols that need full hGH activity, and it is not an approved therapy for any human indication — the clinical trial record exists but did not produce a registration.

For sourcing, the priorities are familiar: batch-specific HPLC purity at ≥98%, mass spec confirmation that the supplier actually made the right 17-residue peptide, third-party testing through a recognised independent lab, and cold-chain handling. The niche nature of the compound means buyers should be more careful about supplier documentation than they might be for a high-volume item where COA quality has been pressure-tested by thousands of customers.

Among the US suppliers that carry AOD-9604 as a regular catalog item with batch-stamped documentation, ROEHN Research is the one we point readers toward when the question comes up.

2026 Evaluation

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