Refrigerate reconstituted peptides at 2-8°C (36-46°F) immediately after mixing. This is the single most important storage rule. Temperature control determines whether your peptide lasts its full shelf life or degrades in days.
Temperature Requirements
The target range is 2-8°C, which is a standard household refrigerator setting. Most refrigerators run at about 3-4°C. Place the vial in the main compartment, not the door. Door shelves experience wider temperature swings from repeated opening.
Avoid these temperature mistakes:
- Do not store on the refrigerator door
- Do not place directly against the back wall (risk of accidental freezing)
- Do not leave at room temperature between uses. Take the vial out, draw your dose, and put it back. The entire process should take under two minutes.
- Do not freeze reconstituted peptides. Freeze-thaw cycles cause aggregation and loss of potency.
Unreconstituted (lyophilized) peptides are more temperature-stable. They can tolerate brief periods at room temperature during shipping. But once water is added, degradation accelerates at higher temperatures.
Light Sensitivity
Many peptides are light-sensitive. UV and visible light can break down peptide bonds over time.
Protection methods:
- Keep vials in their original box or a closed container inside the fridge
- Wrap vials in aluminum foil if they will be exposed to light for any reason
- Some vendors ship peptides in amber-tinted vials, which offer partial protection
Direct sunlight will degrade a reconstituted peptide noticeably within hours. Ambient indoor light is less of a concern for brief exposures (drawing a dose), but prolonged exposure on a countertop should be avoided.
Shelf Life by Peptide
Shelf life varies by peptide. These numbers assume proper refrigeration at 2-8°C with bacteriostatic water.
| Peptide | Reconstituted Shelf Life | |---|---| | BPC-157 | 28 days | | Semaglutide | 28 days | | Tirzepatide | 28 days | | PT-141 | 28 days | | TB-500 | 21 days | | CJC-1295/Ipamorelin | 21 days | | GHK-Cu | 21 days | | Sermorelin | 21 days | | AOD-9604 | 21 days | | Selank | 21 days | | Semax | 21 days | | MOTS-c | 21 days | | DSIP | 14 days |
These are conservative estimates. Some users report peptides remaining effective beyond these windows, but potency declines progressively. For consistent dosing, replace vials that have exceeded their shelf life.
Signs of Degradation
Discard a reconstituted peptide if you observe any of the following:
Cloudiness. A properly reconstituted peptide should be clear. Cloudiness indicates protein aggregation or microbial contamination. Either way, the vial is compromised.
Visible particles. Floating specks, strands, or sediment mean the peptide has degraded or the solution is contaminated.
Color change. Most peptide solutions are colorless. GHK-Cu has a natural blue tint, which is normal. Any unexpected yellowing, browning, or darkening in other peptides suggests oxidation or degradation.
Unusual smell. Bacteriostatic water has a faint benzyl alcohol scent. Any strong, foul, or unfamiliar odor is a sign of bacterial growth.
When in doubt, discard. Peptides are not expensive enough to justify using a potentially contaminated or degraded solution.
Labeling
Label every vial immediately after reconstitution. Include:
- Peptide name
- Concentration (e.g., 5mg in 2ml = 2,500mcg/ml)
- Date reconstituted
- Discard date (reconstitution date + shelf life)
A small strip of lab tape and a fine-tip marker works well. Some users write directly on the vial cap with a permanent marker.
Travel and Transport
Traveling with reconstituted peptides requires maintaining the cold chain.
Short trips (under 8 hours):
- Use a small insulated lunch bag with an ice pack
- Wrap the vial in paper towel to prevent direct contact with the ice pack (avoid freezing)
- Keep the bag closed as much as possible
Longer travel:
- Use a medical-grade travel cooler designed for insulin
- Battery-powered coolers maintain a steady 2-8°C range
- TSA and most international airport security allow injectable medications with documentation. Carry your peptides in original labeled vials.
Air travel tips:
- Pack in carry-on, not checked luggage (cargo holds can freeze)
- Bring your syringes in their sealed packaging
- A letter from your prescribing provider helps, though it is rarely requested for small quantities
If the cold chain is broken for more than a few hours, assume reduced potency. The peptide may still work, but you cannot verify its integrity visually.