How to Store Peptides
Proper storage is critical. Temperature, light, and handling all affect potency. Get it right to avoid wasting expensive peptides.
Quick Reference
| State | Temperature | Shelf Life | Notes |
|---|---|---|---|
| Lyophilized (powder) | Freezer: -4°F (-20°C) | Months to years | Best long-term option. Stable and resilient. |
| Lyophilized (powder) | Fridge: 36–46°F (2–8°C) | Several months | Fine for short-to-medium term before reconstitution. |
| Reconstituted (BAC water) | Fridge: 36–46°F (2–8°C) | ~28 days | The benzyl alcohol preservative prevents bacterial growth. |
| Reconstituted (sterile water) | Fridge: 36–46°F (2–8°C) | 24 hours | No preservative — bacteria can grow. Use immediately. |
Temperature Guidelines
Temperature is the single most important factor in peptide storage:
- Never freeze reconstituted peptides — the ice crystals can damage the peptide structure. Only freeze lyophilized (powdered) peptides.
- Never leave peptides at room temperature — heat accelerates degradation. Even a few hours at room temperature can reduce potency.
- Avoid temperature fluctuations — don't store peptides in the fridge door (which opens and closes). Place them in the back of the fridge where temperature is most stable.
Light Sensitivity
Many peptides are light-sensitive and degrade when exposed to UV or direct light. Best practices:
- Keep peptides in their original amber or opaque packaging when possible
- Store in a dark container or wrap vials in aluminum foil
- Don't leave vials on your desk or counter — return them to the fridge immediately after use
Handling Best Practices
- Minimize needle punctures — each time you pierce the rubber stopper, you create a potential contamination point. Some users draw multiple doses at once (pre-loading syringes) but this has its own contamination risks.
- Always swab the vial top before every draw — even if you just swabbed it for the last dose.
- Label your vials — mark the date of reconstitution, the peptide name, and the concentration. This prevents dosing errors and tells you when the 28-day window expires.
- Don't shake — vibration and agitation can damage peptide bonds. Handle vials gently.
Shelf Life by Peptide
Not all peptides are created equal when it comes to stability. Some last months once reconstituted, while others degrade quickly — meaning you may not be able to use the entire vial before it expires. Factor this into your dosing schedule and vial size choices.
| Peptide | Lyophilized (Frozen) | Lyophilized (Fridge) | Reconstituted (Fridge) | Notes |
|---|---|---|---|---|
| BPC-157 | 2+ years | 6-12 months | ~28 days | Relatively stable. Standard shelf life. |
| TB-500 | 2+ years | 6-12 months | ~28 days | Good stability. Often paired with BPC-157. |
| Ipamorelin | 2+ years | 6-12 months | ~28 days | Very stable peptide. Standard shelf life. |
| CJC-1295 | 2+ years | 6-12 months | ~28 days | DAC modification improves stability. |
| CJC-1295 (no DAC) | 2+ years | 3-6 months | ~21 days | Slightly shorter reconstituted life than average. |
| PT-141 | 2+ years | 6-12 months | ~28 days | Stable. Often used infrequently — buy small vials. |
| Melanotan II | 2+ years | 6-12 months | ~30 days | Good stability. Light sensitive — wrap in foil. |
| GHK-Cu | 1-2 years | 3-6 months | 14-21 days | Copper complex degrades faster. Use smaller vials. |
| AOD-9604 | 1-2 years | 3-6 months | 14-21 days | Less stable. Plan your dosing to finish the vial. |
| Semaglutide | 2+ years | 6-12 months | ~56 days | Exceptionally stable once reconstituted. Long dosing windows. |
| Tirzepatide | 2+ years | 6-12 months | ~28 days | Standard stability. Keep refrigerated. |
| IGF-1 LR3 | 1-2 years | 3-6 months | ~14 days | Degrades quickly. Requires acetic acid (0.6%) as solvent. Plan dosing carefully. |
All reconstituted shelf lives assume bacteriostatic (BAC) water and continuous refrigeration at 36–46°F (2–8°C). Sterile water has no preservative — use within 24 hours regardless of peptide type. Room temperature storage is never recommended for reconstituted peptides and dramatically shortens lyophilized shelf life.
Planning Around Shelf Life
One of the most common beginner mistakes is reconstituting a large vial and not being able to use it all before it expires. Here's how to plan:
- Calculate total doses per vial — divide the vial size (e.g. 5mg) by your per-dose amount (e.g. 250mcg) to get total doses (20 in this example).
- Calculate days to finish — divide total doses by doses per day. If you inject once daily, that's 20 days. If every other day, that's 40 days.
- Compare to shelf life — if your "days to finish" exceeds the reconstituted shelf life, buy a smaller vial or increase your reconstitution volume to get more concentrated doses.
- Consider peptide.locker — our dosing calculator can help you figure out exact volumes and concentrations.
Storage Mistakes That Waste Peptides
- Leaving reconstituted vials on the counter during injection prep (put it back in the fridge ASAP)
- Storing in the fridge door (temperature fluctuations)
- Using reconstituted peptides past 28 days
- Freezing reconstituted peptides
- Shipping peptides without cold packs in warm weather