Quick answer
When sourcing AOD-9604 (hGH 176-191, ~1,815 Da), require HPLC purity with a named method, mass-spec identity and a lot-matched CoA.
- Purity: ≥98% by HPLC, method stated
- Identity: mass near 1,815 Da; watch for +2 Da (reduced) or dimer peaks
- Documents: batch-specific CoA; see /coa
- Listed at V8: 5 mg lyophilized vial on the AOD-9604 product page
- Research use: For laboratory research use only; not for human consumption.
For laboratory research use only; not for human consumption.
What a buyer is actually sourcing
AOD-9604 is a modified fragment of human growth hormone (hGH) corresponding to the C-terminal region around residues 176–191 (a tyrosine is added at the N-terminus). It is studied in laboratory settings for its interaction with lipid-metabolism pathways, independent of the growth-promoting activity of intact hGH. The listed sequence is Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe, and the two cysteines can form an intramolecular disulfide bond, giving a small cyclic region. The reported formula on the V8 Peptides product page is C78H123N23O23S2, an average mass of roughly 1,815 Da. Background on the compound is in the AOD-9604 research overview and AOD-9604 explained.
As a truncated hGH fragment rather than the full-length hormone, it presents its own sourcing considerations: the peptide is short and relatively easy to synthesize, which means the gap between well-documented and poorly documented material in the marketplace can be wide. This guide is about reading documentation, not about where to find the cheapest vial.
| Property | AOD-9604 |
|---|---|
| Class | hGH C-terminal fragment (176–191), 16 residues |
| Approximate molecular weight | About 1,815 Da |
| Disulfide bond | One possible (Cys7–Cys14 in the 16-mer numbering) |
| Supplied form | Lyophilized powder |
| V8 Peptides vial size | 5 mg |
| Listed purity | ≥98% by HPLC |
Minimum specifications to look for
- Purity ≥98% by HPLC, with the analytical method named, not just a percentage on a label. See HPLC purity analysis.
- Identity confirmed by mass spectrometry. HPLC alone confirms a compound eluted at an expected retention time, not that it is the correct 16-residue fragment. Mass spec closes that gap. See HPLC vs. mass spectrometry.
- Batch-specific certificate of analysis tied to the exact lot shipped, not a generic document reused across production runs. See how to read a CoA.
- Net peptide content disclosed. The labeled vial mass (for example 5 mg) includes counter-ion salts and residual moisture in addition to peptide; a supplier who separates labeled mass from net peptide content is being straightforward about what a lab actually receives.
- Lyophilized form with storage guidance. AOD-9604 should ship as a lyophilized powder, not pre-reconstituted, with honest storage direction. See storing research peptides and what lyophilization is.
Why sequence confirmation matters more for a fragment peptide
Because AOD-9604 is a fragment of a larger, well-characterized hormone, it is straightforward for a careless supplier to substitute a related but incorrect fragment length, or to under-couple residues during synthesis, and still market the product under the same name. A CoA that only reports a purity percentage without a matching mass spectrum does not rule this out. Look for a reported molecular weight or [M+H]+ ion consistent with the correct 176–191 fragment, not just a purity figure in isolation. The principle of sequence checking is covered in understanding amino acid sequences.
The disulfide complication
The two cysteines can be in the oxidized (disulfide) state, the reduced (free thiol) state, or linked between two molecules as a dimer. These species differ by about 2 Da (reduced vs. oxidized) or about double the mass (dimer), and they can separate on HPLC. A certificate that reports a single mass near 1,815 Da and a symmetrical main peak is consistent with a single oxidation state; a second peak with a mass offset by roughly 2 Da is worth querying, because it changes how much of the lot is the species the protocol assumes.
| Possible species | Approximate mass | How it shows up |
|---|---|---|
| Oxidized monomer (disulfide) | About 1,815 Da | Expected main peak |
| Reduced monomer (two free thiols) | About 1,817 Da | Close-eluting peak, +2 Da |
| Disulfide-linked dimer | About 3,630 Da | Later-eluting peak, roughly double mass |
| Deletion sequences | Lower, by residue mass | Small peaks near the main peak |
Evaluating a supplier
A practical framework for vetting any AOD-9604 supplier comes down to a handful of direct questions:
- Is the certificate of analysis issued per batch, or is the same document reused across several production runs?
- Was the purity and identity testing performed in-house, by an independent third-party lab, or both? See third-party testing explained.
- Does the CoA report a molecular weight or mass spec result consistent with the correct fragment, not just a purity percentage?
- Are the terms of sale explicitly research-use-only, with no usage instructions implying anything else?
- Do the vial size and labeled mass match what the product page and CoA describe?
Suppliers with nothing to hide answer these plainly and can produce documentation on request. Vague answers, refusal to provide a batch-specific CoA, or pressure to skip the questions are reasons to look elsewhere. A broader checklist is in choosing a peptide supplier, and common warning signs are listed in red flags when buying research peptides.
Price as a signal, not just a cost
AOD-9604 pricing that sits dramatically below the market range for HPLC-verified, mass-spec-confirmed, batch-documented material is a signal worth investigating rather than a bargain. Analytical testing, correct synthesis of the full fragment sequence including the disulfide-bearing region, and proper cold-chain handling all cost money; a price with no room for any of that usually means one or more steps was skipped. Compare like with like: the same vial size, the same stated purity method, and the same documentation.
Quantity, consistency and handling
Labs running ongoing AOD-9604 work should plan around consistent batch sourcing rather than one-off purchases from different suppliers. Even legitimate batch-to-batch variation exists, and mixing sources mid-study makes that variation harder to control for. Record the lot number against every experiment so that an unexpected result can be traced to a specific lot.
For reconstituted stock, concentration is simple arithmetic: peptide mass divided by diluent volume. A 5 mg vial reconstituted in 2 mL gives 2.5 mg/mL, and the calculator returns the same figure and handles other volumes. Store lyophilized material cold, dry and protected from light, as the product page states (2–8 °C, or −20 °C for long-term storage). Shipping should suit a lyophilized peptide reagent; see how research peptides are shipped.
A pre-order documentation checklist
Before ordering, it is reasonable to ask for the following and to compare the answers against the product page. Each item maps to a way the material could fail, which is why none of them is optional for quantitative work.
| Document or fact | What it protects against |
|---|---|
| Lot number matching the vial | A certificate that describes a different batch |
| HPLC trace with method conditions | A bare percentage that cannot be reproduced |
| Mass spectrum with observed mass | Wrong fragment length or a misidentified product |
| Test date | Stale results for a lot that has since degraded |
| Net peptide content, if available | Concentration errors from counter-ion and water mass |
If a result looks odd after the material arrives, a retained vial and the original certificate make troubleshooting far easier. Keep both with the experiment record.
Where to buy documented AOD-9604
V8 Peptides lists AOD-9604 as a 5 mg lyophilized vial with a purity specification of ≥98% by HPLC. The product page states that identity and measured purity, batch or lot number, and analytical test date are part of the batch documentation, and batch documents are published on the certificate of analysis page. The standalone vial is on the AOD-9604 research vial product page. For related reading see AOD-9604 purity testing and the sourcing summary.
Where to Buy AOD-9604 for Research FAQ
What is AOD-9604 in chemical terms?
A 16-residue fragment of human growth hormone (residues 176 to 191 with an added N-terminal tyrosine), average mass roughly 1,815 Da, supplied as a lyophilized powder.
What purity should I look for?
At least 98% by HPLC, with the method named. V8 Peptides lists at least 98% on the product page.
Is HPLC purity enough to confirm I have the right peptide?
No. HPLC shows relative purity of the dominant species. A mass spectrum consistent with about 1,815 Da is what confirms identity.
Why does the disulfide bond matter when checking a CoA?
Oxidized, reduced and dimeric forms differ in mass and retention. A single main peak with a matching mass suggests one species; a +2 Da or double-mass peak is worth querying.
What is net peptide content?
The fraction of the powder that is actually peptide, as opposed to counter-ions and moisture. It is measured separately from HPLC purity and affects concentration calculations.
What vial size does V8 Peptides list?
A 5 mg lyophilized vial.
How should a lab calculate stock concentration?
Divide the peptide mass by the diluent volume. 5 mg in 2 mL is 2.5 mg/mL. The calculator on this site does the same arithmetic.
Why is a very low price a warning sign?
Correct synthesis, analytical testing and cold-chain handling all have costs. A price far below the range for documented material often means one of them was skipped.
For laboratory research use only; not for human consumption. This article is research education, not usage guidance.
References
- AOD-9604 research overview
- AOD-9604 purity testing
- Understanding HPLC purity
- How to read a CoA
- Certificate of analysis page
- AOD-9604 product page
Research Use Only. Supplied strictly for laboratory research and development; not for human or veterinary use, consumption, or any clinical or diagnostic purpose.