Peptide stability during shipping: what we test and why

Lyophilized peptides are surprisingly tolerant of ambient-temperature shipping for short windows — typically up to two weeks at room temperature without measurable degradation. The exceptions, and how we handle them, are worth understanding.

What's robust

Most short peptides (under 30 residues) without sensitive modifications survive multi-day ambient transit fine. The lyophilization itself protects against hydrolysis.

What's fragile

• Long sequences with cysteine residues can oxidize.
• Acylated peptides (semaglutide, tirzepatide) prefer cold transit.
• Disulfide-bridged sequences are sensitive to heat.

For these we use insulated packaging with phase-change packs.

Receiving best practice

When your shipment arrives, transfer to -20°C immediately if you don't plan to reconstitute within 24 hours. Inspect the vial — any discoloration, moisture, or visible particles is a reason to contact us before using.