AOD-9604: Research Reference

AOD-9604 is a 16-residue synthetic peptide: the C-terminal fragment of human growth hormone, residues 177 to 191, with a tyrosine added at the N-terminus. Its two cysteines are joined in a disulfide bond that closes most of the chain into a ring, and that ring is the centre of both its chemistry and its stability.

This reference collects what a laboratory needs to know about AOD-9604 as a material: how its 16 residues and its disulfide ring behave in the vial, what it dissolves in, how it is handled at the bench and what to do when an order arrives. Each section below has its own page.

Molecular reference

Name	AOD-9604
Also known as	AOD9604, hGH fragment 176-191 (Tyr)
Sequence	Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe (YLRIVQCRSVEGSCGF; disulfide Cys7-Cys14)
Residues	16
Molecular formula	C78H123N23O23S2
Molecular weight	1815.1 g/mol
CAS number	221231-10-3

Formula, molecular weight and CAS number are from PubChem (CID 71300630), and the same figures and sequence appear in the specifications on our AOD-9604 product page. The fragment’s identity, growth hormone residues 177 to 191 with an added N-terminal tyrosine, is as described in the published analytical work (Cox et al., Drug Testing and Analysis, 2015). The disulfide position is recorded on our storage page from a chemical supplier’s formal name for the compound. Note that the product URL reads 10mg; the vial we supply is 5 mg.

Three features explain most of its behaviour. The disulfide bond between Cys7 and Cys14 ties the chain into a loop, and both cysteines are already paired, so there is no free thiol left to oxidise, though the bond itself can still break down (Trivedi et al., Current Protein and Peptide Science, 2009). The ring appears to protect what it encloses: when the peptide was incubated in serum, the fragment that stood out as significantly more stable than the parent compound or the other metabolites was CRSVEGSCG, the bridged loop (Cox et al., Drug Testing and Analysis, 2015). And the rest of the sequence is chemically quiet: there is no methionine, no asparagine and no aspartic acid, leaving one glutamine, one tyrosine and one phenylalanine as the only other reactive or light-absorbing residues.

What it is studied for

AOD-9604 came out of work on the fat-metabolism region of growth hormone. In obese mice, 14 days of either growth hormone or the fragment reduced body weight gain, raised fat oxidation and raised plasma glycerol, an index of lipolysis. Unlike the full hormone, the fragment did not cause high blood sugar or reduce insulin secretion, and in cell assays it neither competed for the growth hormone receptor nor drove cell proliferation (Heffernan et al., International Journal of Obesity, 2001). The authors read this as evidence that growth hormone can act as a pro-hormone whose fragments work through other routes.

It reached human testing in the 2000s and was later listed as banned in sport by the World Anti-Doping Agency, which is why the analytical literature exists at all (Cox et al., Drug Testing and Analysis, 2015). Our summary of the human trial record, including the pooled safety analysis and the obesity studies, is in the AOD-9604 human studies page, and a comparison with another growth hormone related peptide is in AOD-9604 vs tesamorelin.

Laboratory work has also looked at cartilage, with a rabbit knee model reported on the human studies page. No study of how the peptide behaves in a stored research vial has been published.

Stability

Its concerns are the disulfide bond, slow deamidation at its single glutamine, and the physical stresses that affect any peptide solution. The AOD-9604 stability page covers those routes, freeze-thaw, light and what visible changes mean.

Solubility

By our calculation AOD-9604 carries a small net positive charge near neutral pH. No measured water solubility figure was available to us, so the pages work from its sequence and our own concentration tables. The AOD-9604 solubility guide explains why, which concentrations dissolve cleanly and what causes haze.

Handling

Bench practice for AOD-9604 is mostly about keeping the solution cold, clean and labelled. The AOD-9604 handling page lists the steps and the common mistakes.

On arrival

What a sealed vial should look like, why it travels without an ice pack and where it goes first are on the AOD-9604 on-arrival page.

Storage and reconstitution

Fridge and freezer windows, before and after mixing, are on how long AOD-9604 lasts. Water volumes and the concentration table for a 5 mg vial are on how much bacteriostatic water for a AOD-9604 5 mg vial.

FAQ

Short answers to the questions researchers ask most about storing, mixing and handling AOD-9604 are on the AOD-9604 FAQ.

Where to get it

Vistara Labs supplies AOD-9604 as a lyophilised 5 mg vial for laboratory research, shipped within Canada by Canada Post Xpresspost. There is no AOD-9604 nasal spray. Certificates are on our lab reports page.