Cold Chain
Also known as: temperature-controlled shipping · refrigerated logistics
Cold chain is the unbroken control of temperature for a temperature-sensitive product, from manufacture through shipping and storage to use.
A cold chain is the set of storage and shipping steps that keep a product within its required temperature range at every point: the manufacturer, the warehouse, the courier, and your own fridge. The required range comes from stability testing and is stated on an approved product's label. For many biologics that range is refrigerated, but not always: some labels call for room temperature, and many forbid freezing.
A break in the chain is called a temperature excursion. Whether an excursion matters depends on the product, how hot or cold it got, and for how long. For approved drugs, manufacturers test and publish how much excursion a product can tolerate. A 20-year review found that of 705 products approved by the FDA since 2000, 246 required storage below room temperature, and allowable room-temperature excursion periods could be identified for 214 of them.
Why it matters
Peptides and proteins degrade by chemical and physical pathways, and storage conditions affect how fast. Even for human insulin, one of the best-studied peptide hormones, a Cochrane review found product-specific results: some storage above recommended temperatures caused no meaningful loss, while two laboratory studies reported up to 18% loss of insulin activity after one week to 28 days at 37 °C.
For research peptides there is usually no tested excursion data, so you cannot know how much a warm shipment cost you. Rules of thumb such as 'powder is fine at room temperature for weeks' are not backed by data for most of these compounds. What you can control is how the product is shipped, how fast you store it, and whether you follow the storage conditions the seller states.
How to check the cold chain on arrival
- Before ordering, read the seller's stated storage temperature and shipping method.
- On arrival, note whether cold packs are still cold and how long the package was in transit.
- Store the product at its stated temperature right away; do not freeze anything whose label or seller says not to.
- Record the arrival date, condition and lot number so a later problem can be traced.
- If a package arrives warm or delayed, contact the seller before using the product and ask what their replacement policy is.
Common mistakes
- Assuming every peptide product should be refrigerated; some approved products are stored at room temperature and must not be refrigerated after mixing.
- Freezing a powder or solution when the label or seller says not to freeze it.
- Assuming a vial that looks normal was not damaged by heat; degradation is often invisible.
- Applying an insulin or other approved drug's excursion data to an untested research peptide.
- Leaving a delivered package outside or in a hot car before storing it.
Sources
- ReviewAllowable room temperature excursions for refrigerated medications: A 20-year review. Am J Health Syst Pharm, 2022. PMID 35451022.
- Systematic reviewThermal stability and storage of human insulin. Cochrane Database Syst Rev, 2023. PMID 37930742.
- Prescribing informationEGRIFTA WR (tesamorelin) for injection - prescribing information and instructions for use. DailyMed, U.S. National Library of Medicine, 2025.
Page updated . How we grade evidence: methodology.
Related Terms
Lyophilization
Lyophilization (freeze-drying) removes water from a frozen product under vacuum, leaving a dry powder or cake that is more stable than a solution.
Vial Shelf Life
Vial shelf life ends at the earlier of the original expiration date and the applicable limit after opening or mixing.
Vendor Trust Score
DoseCraft's vendor trust score is an editorial rating of a peptide seller's documentation, testing claims, reputation and business details, not a lab result.
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