Peptide Storage & Reconstitution Guide
A plain-English guide to storing research peptides and turning the freeze-dried powder into a usable solution, without damaging it. For laboratory research use only.
Pepcore peptides arrive as a freeze-dried powder. Keep them cold, and when you are ready to use one, dissolve it in a measured amount of liquid (a diluent) to a known strength. This guide covers storage temperatures and shelf life, then walks through reconstitution step by step, gently, so the peptide stays intact. Everything here is for laboratory research use only.
Storing your peptides
Keep the powder cold, and know roughly how long it lasts.
Freeze-dried powder travels well. The lyophilized form is stable and shielded from light, so short spells at room temperature in transit are fine. Even so, refrigerate or freeze it as soon as it arrives.
For storage, a fridge at 2-8°C is fine short term, and a freezer at -20°C is best for the long term. Keep peptides away from direct light, heat, and moisture.
Peptides break down slowly over time. Early on that is not a problem, but as they degrade they lose their shape and charge, which eventually affects integrity. Cold, dry storage slows this right down.
Shelf life by peptide type
Rough guidelines. Always follow the Certificate of Analysis for the specific compound.
How each type dissolves
These durations are general research-storage estimates, broadly the same across peptide types, not a guarantee for any specific batch. The COA included with your order is the reference for that compound.
Reconstitution, step by step
Turning the powder into a solution without damaging it.
1Let everything reach room temperature
Take the peptide vial and the diluent out of the fridge and let them warm to room temperature first. Mixing while cold can leave the solution cloudy.
2Equalise the vial pressure
Freeze-drying can leave a vacuum or a little extra pressure in the sealed vial. Insert a sterile needle holding a small amount of air into the rubber stopper to balance it, the vial will draw in or release air. This stops liquid being pushed back out when you add it.
3Choose your diluent
Bacteriostatic or sterile water suits most peptides. Some need a little dilute acetic acid, and hydrophobic peptides may need roughly 50% aqueous acetic acid to dissolve fully. It often helps to make a slightly stronger stock solution and dilute it later.
4Add it gently
Let the liquid run slowly down the inside wall of the vial rather than straight onto the powder. Then swirl gently until it is fully dissolved. Never shake, that can damage the peptide.
5Get the volume right
More liquid is not better, it just over-dilutes. A typical reconstitution uses about 1 to 2.5 ml. Let the calculator work out the exact volume for the concentration you want.
After reconstitution
A few finishing touches once it is in solution.
Frequently asked questions
Quick answers to the questions we hear most.
How long do peptides last?
Freeze-dried powder at -20°C generally keeps for 12-24 months. Once reconstituted, use it within about 2-8 weeks kept at 2-8°C. Always check the COA for the specific compound.
What liquid do I use to reconstitute?
Usually bacteriostatic or sterile water. Some peptides need a little dilute acetic acid, and hydrophobic ones may need roughly 50% aqueous acetic acid to dissolve fully.
Can I shake the vial to dissolve it faster?
No. Swirl it gently instead. Shaking can break down the peptide and damage its structure.
How much liquid should I add?
Typically 1 to 2.5 ml. Use the peptide calculator to hit your target concentration exactly.
Work out the exact diluent volume and concentration in seconds, then browse research-grade peptides supplied at 99% HPLC purity with a COA included.
All Pepcore peptides are supplied as 99%+ pure freeze-dried powder with a Certificate of Analysis, strictly for laboratory research use only, and are not for use in people or animals.