Lyophilized (freeze-dried) peptides do not degrade during normal shipping without refrigeration. The main cause of peptide degradation is water, and it has been removed from lyophilized powder. An accelerated stability test of BPC-157 showed that even 28 days at 40 °C and high humidity did not reduce purity by more than about 2 percentage points.[4] Refrigeration is only necessary once the peptide is dissolved and for long-term storage.
In brief
- Powder (lyophilisate): days to weeks at room temperature are fine; a freezer for long-term storage.
- Solution: always in the fridge (2–8 °C), use within a few weeks.
- The biggest enemies: water, repeated freezing and thawing, direct light.
Why do peptides degrade?
Peptides are chains of amino acids joined by peptide bonds. In solution they can degrade in several ways:[3]
- Hydrolysis – water breaks the peptide bond and the chain falls apart into shorter segments.
- Deamidation – the amino acids asparagine and glutamine lose their amide group, which changes the charge and shape of the molecule.
- Oxidation – methionine, cysteine and tryptophan are especially sensitive, particularly in the presence of oxygen and light.
- Aggregation – molecules clump together and lose activity.
All these reactions need water or the movement of molecules in solution to take place. That is why the form in which a peptide is shipped matters more than the temperature.
What is lyophilization and why does it protect peptides?
Lyophilization is freeze-drying. The peptide solution is frozen and the ice is removed under vacuum by sublimation, without melting. What remains is a dry, porous “cake” with a very low water content. The peptide molecules in it are immobilised in a glassy state, and chemical reactions proceed extremely slowly.[1]
The pharmaceutical industry lyophilizes protein and peptide drugs precisely for stability – the lyophilisate lasts much longer and withstands temperature fluctuations that a solution would not.[2]
What did the BPC-157 stability test show?
To verify how a lyophilized peptide behaves under extreme conditions, the independent analytical laboratory Liquilabs carried out an accelerated stability test of BPC-157 in its original sealed vials:[4]
| Parameter | Test conditions |
|---|---|
| Temperature | Constant 40 °C |
| Relative humidity | Constant 75% |
| Duration | 28 days without interruption |
| Packaging | Original hermetically sealed glass vials |
Results after four weeks:
- The active substance content stayed within the 90–110% range required by the European Pharmacopoeia.
- HPLC purity dropped only slightly, from about 98% to 96%.
- After dissolving, colour, clarity and solubility were unchanged.
The test conditions – 40 °C for a whole month – are much harsher than normal shipping, which takes a few days at temperatures around room temperature. The result applies to BPC-157; peptides with more sensitive amino acids (such as methionine or cysteine) may be more prone to oxidation, but even for them the lyophilized form greatly slows down degradation.
Why does the cold-shipping myth persist?
- Mixing up powder and solution. A dissolved peptide really does need a fridge. This rule is then wrongly applied to the powder as well.
- Mixing up storage and shipping. For storage over months to years a freezer is ideal, but a few days at room temperature have practically no effect on the purity of the powder.
- Manufacturer caution. The recommendation “store cold” is worded with a safety margin and says nothing about what the peptide can actually withstand.
How should peptides be stored correctly?
| Form | Short term | Long term |
|---|---|---|
| Lyophilized powder | Room temperature, in the dark | Freezer (−20 °C) |
| Dissolved peptide | Fridge (2–8 °C) | Usually a few weeks at most in the fridge |
Rules for the solution: do not freeze it repeatedly, protect it from light and work cleanly when drawing from it. Bacteriostatic water, whose benzyl alcohol prevents bacterial growth, is the most common solvent. Our peptide calculator works out the solution concentration.
How can you tell a peptide has degraded?
Lyophilized powder should be white and free-flowing or form a compact cake. Yellowing, clumping or a damp appearance is a warning sign. A solution should be clear; cloudiness, flakes or a change of colour mean the peptide is no longer suitable for research. Chemical degradation cannot be seen with the naked eye, however – only HPLC analysis reliably detects it.
How do we ship peptides?
We supply all peptides in lyophilized form in sealed glass vials, in opaque packaging. We usually ship within 24 hours, and delivery across Czechia and Slovakia takes 3–5 business days. We have selected batches tested by independent laboratories for purity and identity; you will find the reports on the peptide test results page.
What should I do if my parcel sat in the heat?
If the parcel spent a day or two in a warm parcel locker or car, the available data show it will not harm a lyophilized peptide – the BPC-157 test assumed a month at 40 °C. When you receive the vial, check that the powder is dry with no signs of moisture and that the vial is intact. Then put it in the fridge or freezer, depending on when you plan to use it. If the powder is clumped, has changed colour or the vial is damaged, contact us.
Why do we supply peptides in glass vials?
Glass does not let air or moisture through and does not react with the peptide. The vials are sealed with a rubber stopper and an aluminium cap, so no air humidity can get in after lyophilization. Thanks to the stopper, the peptide can be dissolved and the solution drawn without opening the vial. This matters both for stability and for the purity of the solution.
How long does a lyophilized peptide last?
When stored in a freezer (−20 °C), dry and dark, most lyophilized peptides last for years. In a fridge you can count on months, and at room temperature on weeks, though the exact time depends on the sequence – peptides containing methionine, cysteine or tryptophan are more sensitive to oxidation. What matters is that no moisture gets into the vial: a cold vial taken out of the freezer should be left to reach room temperature before the stopper is opened or pierced, otherwise water condenses on it.[1][3]
Summary
- The main cause of peptide degradation is water; lyophilized powder is therefore stable at room temperature.[1]
- A BPC-157 test at 40 °C and 75% humidity showed purity falling only from about 98% to 96% after 28 days.[4]
- Refrigeration is necessary once the peptide is dissolved; a freezer is ideal for long-term storage of the powder.
- Do not freeze the solution repeatedly, protect it from light and use it within a few weeks.
- Only HPLC analysis reliably detects degradation, not looking at the vial.
Frequently asked questions
Do I have to put the peptide in the freezer as soon as it arrives?
No, not if you plan to use it soon. A lyophilized peptide lasts for weeks in the fridge or at room temperature in the dark. A freezer is suitable for storage over months or longer.
Can I freeze a dissolved peptide?
It is not recommended. Repeated freezing and thawing damages the peptide’s structure. The solution belongs in the fridge and should be used within a few weeks.
Is light bad for peptides?
Yes, especially for solutions and for peptides containing tryptophan or methionine, which are oxidised by light and oxygen. Store vials in a box or opaque packaging.
How long does a dissolved peptide last?
It depends on the specific peptide. As a general rule, a few weeks in the fridge at 2–8 °C, provided the solution is prepared with bacteriostatic water and handled cleanly.[3]
Why are peptides sold as a powder rather than a ready-made solution?
Because they degrade much faster in solution. The powder withstands shipping and long-term storage, and the solution is prepared just before use in the laboratory.[2]
Can I tell a degraded peptide by its appearance?
Only partly. Yellowing, clumping or a cloudy solution are warning signs, but chemical degradation without visible changes can only be detected by HPLC analysis.
Sources
- Wang W. Lyophilization and development of solid protein pharmaceuticals. International Journal of Pharmaceutics. 2000;203(1-2):1–60. PubMed ↗
- Carpenter JF, et al. Rational design of stable lyophilized protein formulations: some practical advice. Pharmaceutical Research. 1997;14(8):969–975. PubMed ↗
- Manning MC, et al. Stability of protein pharmaceuticals: an update. Pharmaceutical Research. 2010;27(4):544–575. PubMed ↗
- Liquilabs. Analytical report BPC157_08_2025 – accelerated stability study of lyophilized BPC-157 (40 °C, 75% relative humidity, 28 days).
The information in this article is for educational purposes only and does not replace medical advice. The substances described are not approved medicines, and Jolt Peptides products are intended solely for laboratory research, not for use in humans or animals.