Why Storage Matters
Peptides are fragile molecules. Improper storage is the fastest way to turn expensive research compounds into expensive water. Temperature fluctuations, moisture, light exposure, and bacterial contamination can all degrade peptides, reducing their purity and effectiveness.
Getting storage right isn't complicated, but the details matter.
The Two Forms: Lyophilized vs Reconstituted
Every peptide you buy arrives in one of these two forms, and they have very different storage requirements.
Lyophilized (Powder) Form
Lyophilized peptides have been freeze-dried to remove all water. This is the most stable form — the peptide is essentially in suspended animation.
Storage requirements:
- Freezer (-20°C / -4°F): Best for long-term storage. Most peptides remain stable for years at this temperature
- Refrigerator (2-8°C / 36-46°F): Acceptable for medium-term storage (months)
- Room temperature (21-24°C / 70-75°F): Only acceptable for short-term (days to weeks, depending on the peptide)
Key rules:
- Keep away from light — store in a dark container or wrapped in foil
- Minimize moisture exposure — keep the desiccant pack in the container
- Don't repeatedly freeze and thaw — this is more damaging than stable cold storage
- If storing multiple vials, keep unopened ones in the freezer and only move vials to the fridge as needed
Reconstituted (Liquid) Form
Once you add bacteriostatic water (or PBS for GHK-Cu), the clock starts ticking. Reconstituted peptides degrade much faster than lyophilized powder.
Storage requirements:
- Refrigerator (2-8°C / 36-46°F): Required. Most reconstituted peptides last 20-30 days refrigerated when using BAC water
- Never freeze: The freeze-thaw cycle damages the peptide structure and can shatter the vial
- Never leave at room temperature: Bacterial growth accelerates rapidly above 8°C
Key rules:
- Refrigerate immediately after reconstitution
- Keep the vial upright to minimize contact with the stopper
- Minimize the number of times you pierce the stopper (each puncture increases contamination risk)
- Use alcohol swabs on the stopper before every draw
Peptide-Specific Storage Charts
Different peptides have different stability profiles. Here are the key ones based on community data:
Melanotan 2
- Lyophilized at room temp: 12 months
- Lyophilized refrigerated: 48 months
- Lyophilized frozen: 48+ months
- Reconstituted (BAC water) at room temp: 2 months
- Reconstituted (BAC water) refrigerated: Up to 48 months
GHK-Cu
- Lyophilized refrigerated (<4°C): 24 months
- Lyophilized frozen: 36 months
- Reconstituted (BAC water) refrigerated: 6-8 weeks
- Reconstituted (BAC water) frozen: 6-12 months
- Important: GHK-Cu should ideally be reconstituted with PBS, not BAC water. PBS provides the correct pH but has a shorter shelf life (1-2 days without preservative)
Epitalon
- Lyophilized at room temp: 3 weeks only
- Lyophilized refrigerated: 48+ months
- Lyophilized frozen: 48+ months
- Reconstituted refrigerated: 20-30 days
- Reconstituted frozen: 3-12 months
BPC-157
- Lyophilized frozen: Years of stability
- Reconstituted (BAC water) refrigerated: ~30 days
- Oral stability: Unique among peptides — stable in gastric acid
General Rule
- Reconstituted with BAC water: ~30 days refrigerated
- Reconstituted with sodium chloride/sterile water: Use same day (no preservative)
- Reconstituted with PBS: 1-2 days (no preservative unless specified)
Reconstitution Best Practices
The Right Solvent
- Bacteriostatic water (BAC water): The default choice for most peptides. Contains 0.9% benzyl alcohol as a preservative, giving you ~30 days of stability
- Phosphate Buffered Saline (PBS): Required for GHK-Cu and some other copper peptides. Provides correct pH but limited shelf life
- Sodium chloride (saline): No preservative — use immediately and discard remainder. Do not store
- Sterile water: No preservative — single use only
How Much Solvent to Use
A key insight from experienced users: the less bacteriostatic water you use, the greater the stability of the reconstituted solution. For a 5mg vial, 0.5-1mL is sufficient. More water means more dilution and slightly faster degradation.
However, don't use so little that accurate dosing becomes difficult. Find the balance between concentration and practicality.
Reconstitution Steps
- Let the lyophilized vial warm to room temperature before opening (prevents condensation)
- Clean the vial stopper with an alcohol swab
- Draw the desired amount of BAC water into a syringe
- Insert the needle through the stopper at an angle
- Direct the water stream down the side of the vial — never spray directly onto the powder
- Let the vial sit for 10-20 minutes. The powder should dissolve on its own
- If particles remain, gently roll the vial between your palms. Never shake
- Verify the solution is crystal clear. Cloudiness indicates a problem
Common Storage Mistakes
1. Freeze-Thaw Cycling
Taking a vial in and out of the freezer repeatedly is one of the most damaging things you can do. Each cycle allows moisture to condense inside the vial and degrades the peptide structure. Keep vials in one location.
2. Freezing Reconstituted Peptides
Unlike lyophilized powder, reconstituted peptides should never be frozen. The ice crystals can physically damage the peptide chains and the expansion can crack the vial.
3. Using the Wrong Solvent
Using plain sterile water when BAC water is needed means you have no antimicrobial protection. Using BAC water when PBS is required (GHK-Cu) means incorrect pH that degrades the peptide.
4. Room Temperature Storage After Reconstitution
Even a few hours at room temperature accelerates bacterial growth in reconstituted peptides. Refrigerate immediately.
5. Light Exposure
UV light degrades peptides. Store in a dark location or wrap vials in aluminum foil.
6. Overfilling the Vial
Never inject more BAC water than the vial can handle. A 5mL vial should not receive more than 4-5mL of liquid (the powder occupies some space too).
Pre-Loading Syringes
For peptides with short reconstituted shelf lives (like GHK-Cu in PBS), pre-loading individual syringes is a common workaround:
- Reconstitute the full vial
- Immediately draw individual doses into separate insulin syringes
- Cap each syringe and store in the refrigerator (or freezer for longer storage)
- Use one syringe per day
This minimizes the number of times you pierce the vial stopper and allows you to freeze individual doses when the reconstituted solution wouldn't survive freezing in the vial.
Travel and Shipping
- Lyophilized peptides can travel at room temperature for short periods (1-3 days) without significant degradation
- Reconstituted peptides need a cooler with ice packs for any travel
- When receiving shipments, refrigerate or freeze upon arrival
- Look for vendors who ship with cold packs during warm months
For peptide-specific reconstitution details, see our Complete BPC-157 Guide and GHK-Cu Looksmaxxing Guide. Always verify your peptides before use, and check out Peptard's group buys for community-tested products.
This article is for informational and research purposes only. Always follow applicable regulations in your jurisdiction.