Lyophilisation is the process that makes long-term peptide storage possible. This guide explains how it works and why it matters for research compound integrity.
What is lyophilisation?
Lyophilisation — commonly called freeze-drying — is a dehydration process in which a frozen material has its water content removed by sublimation (the direct transition from ice to vapour, bypassing the liquid phase) under vacuum. For pharmaceutical and research applications, this produces a dry, stable solid that retains the molecular structure and bioactivity of the original compound.
It is the process responsible for the solid white puck you find in your peptide vial when it arrives from My UK Peptides.
The three stages of lyophilisation
1. Freezing
The peptide solution is frozen to a temperature typically below −40°C. This is the most critical stage. Slow freezing produces large ice crystals that can damage the molecular structure of the peptide; controlled rapid freezing produces finer crystals with less structural damage and a more porous final product that reconstitutes more readily.
2. Primary drying (sublimation)
With the material frozen, the chamber pressure is reduced and gentle heat is applied. Under these conditions, ice sublimates — converting directly to water vapour — which is then collected by a condenser. This stage removes approximately 95% of the water content and is the longest phase, typically taking hours to days depending on the compound and batch size.
3. Secondary drying (desorption)
Residual unfrozen water molecules adsorbed onto the product surface are removed by further temperature increases under continued vacuum. The target is a final moisture content of typically under 1%, at which point microbial growth and hydrolysis are effectively halted.
Why it matters for your research
A correctly lyophilised peptide:
- Has extended shelf life — most lyophilised peptides are stable for 12–24 months when stored at −20°C
- Is safe for ambient-temperature transport without significant degradation
- Reconstitutes rapidly and completely in aqueous solvent
- Retains its original purity profile as confirmed by the CoA
What does lyophilised peptide look like?
When you receive a vial of lyophilised peptide from My UK Peptides, you will typically see a white, dry powder or compact puck at the base of the vial. The vial may appear almost empty — this is normal. The peptide mass, while small in volume, is present in full. Some sequences produce a fluffy, loosely powdered product; others produce a denser, compressed puck. Both are normal.
Reconstitution after lyophilisation
The lyophilised state is temporary by design. For laboratory use, you will reconstitute the peptide in bacteriostatic water (or another suitable solvent). When doing so, always add the solvent to the vial rather than injecting it forcefully — slow dissolution protects the peptide structure. See our dedicated reconstitution guides for BPC-157, PT-141, TB-500, and other specific compounds.