Metabolic research
Studies on the C-terminal hGH fragment and its reported effects on lipolysis and fat metabolism, using the 177-191 sequence rather than a longer construct.
Peptide · Growth hormone fragment
AOD-9604 (hGH 177-191 fragment)
The sixteen-residue C-terminal fragment of human growth hormone — and the product most often confused with the 176-191 fragment next to it in a catalogue.
Also known as AOD-9604 · AOD9604 · hGH fragment 177-191 · HGH 177-191
Sequence · 16 residues
AcidicBasicHydrophobicPolar
- Residues
- 16
- Molecular weight
- 1815.1
- Formula
- C78H123N23O23S2
- Purity
- 99.1% HPLC
Identity data as printed on the batch certificate of analysis.
Overview
What AOD-9604 is
AOD-9604 is the 16-residue C-terminal fragment of human growth hormone, residues 177 to 191, with a molecular weight of 1,815.1. It is a fragment, not a modified hormone: no part of the molecule is outside the hGH sequence.
That precision matters commercially, because the catalogue next to this one carries the 176-191 fragment. The two differ by a single tyrosine at the N-terminus, which shifts the mass by 163 Da, gives a different CAS number, and makes them different products. A quotation that says “HGH fragment” without a residue range is not telling you which one you are buying.
The batch we hold runs 99.1% by HPLC with total impurities at 0.5%, acetic acid at 6.8% and water at 6.9%. Sixteen residues is short enough that the impurity profile is clean by construction; the analytical question here is identity and counter-ion, not purity.
- Full 16-residue sequence and residue range printed on the certificate
- 99.1% by HPLC; total impurities 0.5%, largest single 0.3%
- Acetate 6.8% — a normal figure for an acetate salt, not a trace
- Distinct CAS from the 176-191 fragment; do not accept a generic “HGH fragment” quote
Identity
The record.
The identifiers your specification sheet, customs paperwork and product label all have to agree on. Where a number depends on the salt form, both are given.
- Chemical name
- hGH(177-191) fragment, acetate salt
- Common name
- AOD-9604; AOD9604
- CAS number
- 221231-10-3
- Molecular formula
- C₇₈H₁₂₃N₂₃O₂₃S₂
- Molecular weight
- 1815.1 g/mol
- Residue count
- 16 (Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe)
- Counter-ion
- Acetate, 6.8% on the current lot
- Appearance
- White or almost white powder
- Solubility
- Soluble in water
- Water content
- ≤ 8.0% (Karl Fischer)
- Storage
- 2–8 °C, sealed, protected from light
- Cysteine residues
- Two (positions 6 and 14)
HS codes are indicative only. Final classification is confirmed per shipment with your customs broker.
Manufacture
How it is made.
Short sequence, two cysteines, and a purity profile that depends more on purification than on coupling efficiency.
- 01
Solid-phase assembly
Sixteen residues couple cleanly; the constraint is the two cysteine residues, which need side-chain protection that survives the rest of the synthesis and is removed without oxidising the thiols.
- 02
Cleavage
Acid cleavage releases the peptide and removes protecting groups. Incomplete removal shows up later as mass variants, which is why identity is confirmed by MS rather than assumed from the sequence.
- 03
Purification
Reversed-phase HPLC removes truncated sequences and oxidised forms. The measured total impurity of 0.5% on the current lot is the result of this step.
- 04
Acetate exchange and drying
Conversion to the acetate and lyophilisation to ≤ 8.0% water, with the acetate figure reported rather than assumed.
Applications
Where it is used.
Supplied to laboratories working on the lipolytic fragment of growth hormone. Research use only.
Comparative work
Side-by-side studies of 176-191 and 177-191, where having both CAS numbers and both sequences documented is the whole point of the comparison.
Analytical standards
A convenient 1,815 Da peptide for method development — large enough to behave like a peptide, small enough to resolve cleanly on a standard C18 gradient.
Specification
Release criteria.
The written limits we release against, with the method used to test each one. Batch results for the lot you receive are stated on its certificate of analysis.
| Parameter | Limit | Method |
|---|---|---|
| Appearance | White or almost white powder | Visual |
| Solubility | Soluble in water | Visual |
| Water content | ≤ 8.0% | Karl Fischer |
| Acetic acid | ≤ 15.0% | HPLC |
| Purity | ≥ 98.0% | HPLC |
| Total impurities | ≤ 2.0% | HPLC |
| Largest single impurity | ≤ 1.0% | HPLC |
| Identity | Conforms to theoretical mass | MS |
| Acetonitrile residue | ≤ 0.041% | GC |
| Dichloromethane residue | ≤ 0.060% | GC |
| DMF residue | ≤ 0.088% | GC |
| Bacterial endotoxin | < 10 EU/mg | LAL |
| Total aerobic count | ≤ 100 cfu/g | Plate count |
| Mould & yeast | ≤ 100 cfu/g | Plate count |
| Shelf life | 24 months from manufacture | Stability programme |
Tighter limits — for example a lower heavy-metal ceiling or a residual-solvent panel — can be quoted against your own specification wording.
Certificate
Reading the certificate.
On a fragment, the certificate has to prove which fragment. That is the first question, not the last.
The residue range must be printed
A certificate that says “HGH fragment” without 177-191 is not specifying the product. The difference from 176-191 is one tyrosine and 163 Da — small enough to pass unnoticed, large enough to make it a different substance with a different CAS.
Acetate around 7% is normal; zero is not
A peptide sold as an acetate salt should show a measurable acetate content. A figure near zero usually means the material is the free peptide and the salt claim is marketing rather than chemistry.
Two cysteines means you should ask about oxidation
Residues 6 and 14 can oxidise, and oxidised forms are close in mass to the target. This certificate reports total and largest single impurities but does not break out oxidised species separately; if your work is thiol-sensitive, ask for that data.
Documentation & packaging
What ships with it.
The paperwork travels with the goods. If your QA team needs an extra declaration, ask before the order is released — some are issued per production lot and cannot be retrofitted.
Certificate of analysis
Purity, impurities, acetate, water, residual solvents and microbiological results for the lot.
Identity data
Mass spectrometry result against the theoretical 1,815.1 Da.
SDS & specification
Safety data sheet and the enterprise standard the batch was released against.
Sequence statement
The full 16-residue sequence with the residue range, so the fragment can be matched against your reference.
| Pack size | Presentation | Typical use |
|---|---|---|
| 1–10 g | Amber vial, 10 mL | Evaluation |
| 25–50 g | Amber vial, 50 mL | Pilot scale |
| 100 g | Amber vial, 100 mL | Small commercial |
| 1 kg+ | Foil bag, quoted per order | Bulk |
Questions
Before you order.
The questions buyers actually ask about AOD-9604. Anything not covered here, ask directly — you will get an answer from someone technical, not a template.
Is AOD-9604 the same as HGH fragment 176-191?
No. AOD-9604 is residues 177-191, CAS 221231-10-3, 1,815.1 Da. The 176-191 fragment carries an additional N-terminal tyrosine, has a different CAS and a mass about 163 Da higher. We list both in the catalogue as separate codes; a supplier quoting “HGH fragment” without a residue range has not told you which product they mean.
Why is there acetate in the product?
Because the peptide is supplied as the acetate salt. Acetate is the counter-ion that balances the charged residues after purification; 6.8% is a normal figure for this molecule. It is not a contaminant, but it does mean the powder is not 100% peptide.
Does the molecule contain a disulfide bond?
It contains two cysteine residues. In the intact hormone those positions participate in disulfide bonding, but this fragment is supplied as the linear peptide and the certificate does not report a disulfide content. Do not assume a cyclic structure.
The batch on file is from 2025 — is that a problem?
The lot is within its retest period (to 2027-07), but for a bulk order ask for the newest batch available. Short peptides are stable, and there is no reason to accept older material when fresher exists.
How should it be stored?
2–8 °C, sealed and protected from light. Equilibrate to room temperature before opening to avoid condensation on the cake.
Can you supply a custom fragment?
Yes — any residue range of hGH, or a different sequence entirely, quoted against your specification. Tell us the range and the counter-ion you need.
Related
Often quoted together.
Quotation
Ask for AOD-9604, by the gram.
Send the quantity, the grade you need and the destination. You will get a written quotation with lead time, packaging options and the documentation set for this material.