Peptide Storage Guide: Temperature, Light & Stability
Proper storage is critical for maintaining peptide integrity. Learn optimal temperatures for lyophilized and reconstituted peptides, understand light sensitivity, and maximize shelf life for your research materials.
Quick Storage Reference
Lyophilized (Powder)
Unreconstituted peptides
- • Short-term: 2-8°C (refrigerator)
- • Long-term: -20°C (freezer)
- • Shelf life: 1-2 years frozen
Reconstituted (Solution)
Mixed with BAC water
- • Storage: 2-8°C (refrigerator only)
- • Never freeze: Damages peptide
- • Shelf life: 4-6 weeks
Peptide stability is directly influenced by storage conditions. Improper storage can lead to degradation, reduced potency, and unreliable research results. This guide covers everything you need to know about preserving peptide integrity.
Storing Lyophilized Peptides
Lyophilized (freeze-dried) peptides are the most stable form. The removal of water during lyophilization significantly slows degradation processes.
Temperature Guidelines
(-4°F)
Long-Term Storage (Recommended)
Best for storage exceeding 3 months. Peptides can remain stable for 1-2 years at this temperature. Use a dedicated freezer, not a frost-free model which cycles temperatures.
(36-46°F)
Short-Term Storage
Suitable for peptides you'll use within 1-3 months. Standard refrigerator temperature. Keep in the back of the fridge where temperature is most stable.
(68-77°F)
Room Temperature (Temporary Only)
Acceptable during shipping or for a few hours during use. Avoid extended exposure. Some peptides like BPC-157 tolerate room temp better than others.
Before Reconstituting Frozen Peptides
Always allow frozen lyophilized peptides to reach room temperature (15-20 minutes) before opening the vial. Opening a cold vial introduces moisture through condensation, which can degrade the peptide before you even add bacteriostatic water.
Storing Reconstituted Peptides
Once reconstituted in bacteriostatic water, peptides enter a less stable state. Proper storage becomes even more critical.
The Only Rule: Refrigerate at 2-8°C
- Standard refrigerator temperature
The same temperature you store milk and vegetables. Not the door (too warm), not the freezer.
- Use within 4-6 weeks
The benzyl alcohol in bacteriostatic water provides antimicrobial protection, but peptides still degrade over time.
- Keep upright and sealed
Store vials upright to minimize rubber stopper contact with solution. Ensure stopper is intact.
NEVER Freeze Reconstituted Peptides
This is the most common storage mistake. When water freezes, ice crystals form and physically tear apart peptide structures. The damage is cumulative with each freeze-thaw cycle.
- • Ice crystals cause mechanical stress on peptide bonds
- • Concentration gradients form during freezing
- • Protein aggregation and precipitation occur
- • Degraded peptides may appear cloudy or have particles
Light Exposure and Photodegradation
Certain peptides are sensitive to light, particularly UV light. Light-sensitive amino acids include tryptophan, tyrosine, phenylalanine, and methionine.
More Light-Sensitive
- • Melanocortin peptides (MT-II, PT-141)
- • Peptides with tryptophan residues
- • GHK-Cu (copper can catalyze oxidation)
- • Some growth hormone releasing peptides
More Light-Stable
- • BPC-157 (highly stable overall)
- • TB-500
- • Simple peptide sequences
- • Peptides without aromatic amino acids
Light Protection Tips
- • Use amber vials when available
- • Store in a closed refrigerator (not on counters)
- • Wrap clear vials in aluminum foil
- • Minimize time outside of dark storage
- • Avoid direct sunlight during reconstitution
Shelf Life by Peptide Type
| Peptide | Lyophilized (-20°C) | Lyophilized (2-8°C) | Reconstituted (2-8°C) |
|---|---|---|---|
| BPC-157 | 2+ years | 6-12 months | 6+ weeks |
| TB-500 | 2+ years | 6-12 months | 4-6 weeks |
| GLP1-S | 1-2 years | 3-6 months | 4-6 weeks |
| GHK-Cu | 1-2 years | 3-6 months | 3-4 weeks |
| Ipamorelin | 1-2 years | 3-6 months | 3-4 weeks |
| CJC-1295 | 1-2 years | 3-6 months | 3-4 weeks |
* These are general guidelines. Actual stability depends on purity, storage conditions, and handling. When in doubt, check for clarity and discard if cloudy.
Frequently Asked Questions
What temperature should I store reconstituted peptides?
Reconstituted peptides should be stored at 2-8°C (36-46°F) in a standard refrigerator. Never freeze reconstituted peptides.
Can I freeze lyophilized peptides?
Yes, lyophilized peptides can be stored at -20°C for 1-2 years. Allow to reach room temperature before reconstituting.
How long do reconstituted peptides last?
Typically 4-6 weeks when stored at 2-8°C in bacteriostatic water. BPC-157 is notably stable for 6+ weeks.
Does light affect peptide stability?
Yes, especially peptides with tryptophan, tyrosine, or methionine. Store in amber vials or dark locations.
What happens if I freeze reconstituted peptides?
Ice crystals damage peptide structure. The peptide may become cloudy, lose potency, or become inactive. Never freeze solutions.