Peptide storage guide

Lyophilized — sealed vial

Lyophilized (freeze-dried) peptides are inherently the most stable form of a peptide. With water removed and the vial sealed under inert atmosphere, the rate of degradation slows dramatically. Recommended conditions:

• -20°C or below — long-term storage. Most BP peptides are stable for 24+ months under these conditions.
• 2–8°C (refrigerator) — short- to medium-term storage. Stable for several months.
• Room temperature — acceptable for shipping windows and brief working storage (days to a few weeks). Avoid prolonged exposure above 25°C.
• Avoid direct sunlight, repeated thermal cycling, and humid environments.

Reconstituted — in solution

Once a peptide is dissolved, water-mediated degradation pathways activate (deamidation, oxidation, hydrolysis). Storage windows shorten substantially:

• 2–8°C in BAC water — most peptides are stable for 2–4 weeks. The benzyl alcohol in BAC water suppresses microbial growth.
• 2–8°C in sterile saline — same window; refrigerate immediately after reconstitution.
• -20°C aliquots — for storage beyond 4 weeks, divide the reconstituted solution into single-use aliquots and freeze. Thaw only what you need.

Freeze/thaw — the silent killer

Each freeze/thaw cycle nucleates ice crystals that physically shear peptide chains and concentrate solutes around the chain. After 3–5 cycles, measurable degradation is typical. Two practical rules:

1. Aliquot before the first freeze, not the second.
2. Thaw on ice, not at room temperature, when possible.

Light, oxygen, pH

• Light: sequences containing tryptophan, tyrosine and phenylalanine are mildly photo-sensitive. Store in amber vials or in a dark cabinet.
• Oxygen: methionine and cysteine residues oxidize in dissolved oxygen. Sealed lyophilized vials are flushed with inert gas; keep them sealed until use.
• pH: most peptides are most stable in slightly acidic-to-neutral solution (pH 5–7). BAC water is near neutral.

Quick-reference table

State	Temperature	Typical stability
Lyophilized, sealed	-20°C	24+ months
Lyophilized, sealed	2–8°C	3–6 months
Lyophilized, sealed	Room temp (≤25°C)	Days–weeks (shipping window)
Reconstituted in BAC water	2–8°C	2–4 weeks
Reconstituted, frozen aliquot	-20°C	3–6 months
Reconstituted, frozen aliquot	-80°C	12+ months

What we ship vs. what you control

Every BP order leaves the lab with cold-pack insulation, but the moment the carrier hands the parcel to you the storage chain is your responsibility. The single most impactful thing you can do is move the vial to the freezer within an hour of unboxing.