In short

Lyophilized powder is a material that has had its water removed by freeze-drying (lyophilization): it's frozen, then the ice is removed directly as vapor, skipping the liquid phase entirely. Most research peptides are supplied this way, not as an arbitrary industry convention, but because peptides (short amino-acid chains) are significantly less stable in solution than in dry form.

How it works

The process has three stages:

  1. Freezing. The peptide solution is frozen quickly to form small ice crystals (this affects the final powder structure).
  2. Primary drying (sublimation). The material is placed under vacuum and gently warmed, the ice converts directly to vapor, bypassing the liquid phase. This is where "freeze-drying" gets its name.
  3. Secondary drying (desorption). Residual unfrozen moisture that was chemically bound to the molecule is removed by raising the temperature further under continued low pressure.

The result is a loose white powder or cake in a vial, sealed under vacuum or an inert gas.

Why it isn't supplied pre-dissolved

The peptide bond and amino-acid side chains are susceptible to hydrolysis, oxidation, and aggregation in an aqueous environment. In solution at room temperature, degradation can occur within days or weeks; lyophilized and properly stored, the same material can remain stable for months to years. That's why the reagent is reconstituted immediately before short-term use in a study rather than kept as a ready solution long-term.

What this means for storage

  • Dry powder is kept in an airtight container, protected from light and moisture, refrigerated (+2…+8 °C) or frozen (-20 °C or below) for long-term storage.
  • Hygroscopicity. Many lyophilizates readily absorb moisture from the air, avoid opening the vial unnecessarily and avoid repeated freeze-thaw cycles, which cause condensation.
  • After reconstitution, stability drops sharply, the solution is typically kept refrigerated and used within a short window, or split into single-use aliquots and frozen.

Not usage instructions

This material is general reference information about the physicochemical properties of lyophilized reagents for laboratory practice. It does not describe dosing or administration schedules for humans. Longeva's products are intended strictly for laboratory research (research use only) and not for use in humans or animals.