Storage is the difference between a research peptide that holds its purity for two years and one that degrades in weeks. Lyophilized peptides are stable, but only under the right conditions. This is how research-grade material should be held.
What degrades a peptide
Three processes account for most loss of purity: hydrolysis (water breaking peptide bonds), oxidation (oxygen attacking side chains on residues like methionine and cysteine), and aggregation. All three accelerate with heat, light, and moisture. Storage is about removing those three inputs.
Lyophilized (powder) storage
In lyophilized form the peptide has almost no water to react with, which is why it is shipped and held as a powder.
- Hold at -20 C for routine storage. For long-term storage, -80 C is preferable.
- Keep the vial sealed and stored with a desiccant to absorb residual moisture.
- Protect from light. Amber or opaque vials and original packaging help.
- Under sealed, cold, dark, dry conditions, lyophilized research peptides commonly hold 95 percent purity
or higher for 24 months or longer.
Brief time at room temperature during shipping is tolerable for lyophilized material, which is why cold-chain is less critical for powder than for solution.
After reconstitution
Once in solution the peptide is far less stable and the clock starts.
- Store reconstituted vials at 2 to 8 C, protected from light.
- Use within days to a few weeks, which is compound dependent.
- For longer holds, aliquot before freezing and thaw each aliquot once. Do not refreeze a partially
thawed aliquot. Repeated freeze-thaw cycles drive aggregation.
Verify before you rely on it
Storage assumptions should be checked against the batch-specific Certificate of Analysis and any compound-specific stability notes. Purity at receipt is only the starting point; handling determines what you actually have at the bench.
For laboratory research use only. Not for human consumption.