What AOD-9604 is
AOD-9604 is a synthetic 16-amino-acid peptide corresponding to residues 176–191 of human growth hormone, with an additional tyrosine at the N-terminus. The underlying idea is a straightforward one in peptide pharmacology: if a large protein has several separable activities, find the region responsible for the one of interest and study it in isolation.
Growth hormone has both growth-promoting and lipolytic activity. The fragment approach isolates the C-terminal region associated with the latter, producing a molecule roughly one-tenth the size of the parent hormone.
Molecular profile
| Property | Value |
|---|---|
| Also known as | hGH fragment 176-191 |
| CAS number | 221231-10-3 |
| Sequence | YLRIVQCRSVEGSCGF |
| Length | 16 amino acids |
| Molecular weight | ~1,815 Da |
| Structural feature | Intramolecular disulfide bridge (Cys7–Cys14) |
| Appearance | White lyophilised powder |
The disulfide bond
The two cysteine residues in the sequence form an intramolecular disulfide bond, closing the peptide into a loop. This is not incidental — the bridge constrains the molecule's conformation, and the conformation is part of what the fragment approach is trying to reproduce from the parent hormone.
Analytically it introduces a subtlety worth understanding. The oxidised (bridged) and reduced (free thiol) forms differ by 2 daltons. On a high-resolution instrument that is a clear distinction; on a low-resolution one it can disappear into the isotope envelope. Two batches can therefore return identical HPLC purity figures and near-identical reported masses while differing in whether the disulfide is actually formed.
Beyond that, cysteines can form intermolecular disulfides between two peptide molecules, producing a dimer of roughly twice the mass. Dimers are usually well separated chromatographically, so they show up as a distinct peak — which is another reason the chromatogram is worth more than the number derived from it.
Research context
AOD-9604 is studied in metabolic research for lipolytic activity in adipocyte models, and comparatively against full-length growth hormone to examine whether the fragment reproduces that activity without the growth-promoting and insulin-antagonising effects of the parent hormone. It also appears in structure-activity work examining which residues within the fragment carry the activity.
Supplied for in-vitro laboratory research only. No therapeutic claim is made and no dosing or administration guidance is provided.
Analytical notes
Three things a certificate for this compound should let you check:
- Sequence identity by mass — confirming the 16-mer against theoretical mass, distinguishing it from a truncation or a different hGH fragment.
- Disulfide state — a 2 Da difference that requires adequate mass resolution to observe. Worth asking about specifically.
- Dimer content — visible chromatographically as a later-eluting peak at roughly double the mass.
A purity percentage on its own addresses none of these directly. See what mass spectrometry establishes that HPLC cannot.
Handling and storage
Store sealed at −20 °C, protected from light and moisture, and bring to room temperature before opening. Cysteine-containing peptides are sensitive to oxidising conditions and to trace metal contamination in diluent, both of which promote disulfide scrambling and dimer formation — use clean diluent and avoid prolonged storage in solution. Store reconstituted material at 2–8 °C, protected from light, and prepare fresh where the work depends on disulfide integrity.
What we supply
Released against a ≥99% purity specification, with HPLC purity and mass spectrometry identity confirmation on every batch and a batch-specific Certificate of Analysis. Select batches additionally receive independent third-party purity verification.