Cold Weather and Medications: What You Should Know
March 04, 2026 | Tags:
Since most drugs are designed to handle brief cold exposure during shipping and delivery, cold weather rarely affects most medications, including mail order prescriptions. However, some medications — such as insulin for diabetes and biologic injectables for autoimmune or inflammatory condition — are temperature sensitive and require extra care.
Does cold weather affect medications?
When temperatures drop, people may worry that cold weather could damage their medications or make them less effective. This is a common concern, but brief exposure to the cold is typically not a problem when medications are otherwise handled and stored properly.
“Medications are tested and packaged to withstand typical shipping and delivery conditions, even during winter months,” said Amber Zuber, Director of Pharmacy at Medical Mutual.
Problems are uncommon for most medications and usually occur only with prolonged exposure to extreme temperatures or with drugs that require temperature control.
Are mail-order medications safe in winter?
Yes, mail-order medications are typically safe during cold weather.
Mail-order pharmacies, like Express Scripts, follow strict handling and shipping standards. These safeguards apply whether you have your medications shipped to your home with mail-order or you fill your medications at a local pharmacy. Both options involve some outdoor exposure during transport, and neither is considered riskier when proper precautions are followed.
"As the spouse of a Type‑1 Diabetic, I rely on Express Scripts Pharmacy’s temperature‑controlled packaging to ensure my husband’s insulin arrives safely and securely every time," said Nicole McMahon, Manager of Pharmacy Operations at Medical Mutual.
Mail-order pharmacies typically use:
- Insulated packaging for susceptible medications.
- Protective materials.
- Shipping timelines and logistics planned around weather conditions.
Which medications are temperature sensitive?
While most medications tolerate brief cold exposure, some drugs require extra care, including:
- Insulin
- Certain injectable medications
- Certain biologic therapies
- Certain vaccines
Extreme temperatures may damage these medications by breaking down key ingredients. In some cases, freezing can make them less effective or unusable, even if there are no visible signs of damage.
Because temperature-related damage is not always obvious, it’s important to follow storage instructions carefully.
How should medications be stored?
Always store medications according to the instructions on the label. Storage requirements typically include keeping medications at:
- Room temperature
- Refrigerated temperatures, when specified
If you’re unsure about how to store a medication, or whether it may have been exposed to damaging temperatures, your pharmacist can help explain proper handling and what warning signs to look for.
How to protect your medications in cold weather
Protect your medications during winter by following these best practices:
- Track mail-order deliveries so you know when packages arrive.
- Bring delivered or picked-up medications indoors as soon as possible.
- Avoid leaving medications in cars, mailboxes or on porches for long periods.
- Store prescriptions consistently according to label directions.
“While brief cold exposure is rarely an issue, prolonged exposure may increase the risk of damage for temperature sensitive medications,” Zuber said. “In other words, it’s not a good idea to leave in a mailbox or on a porch for a week.”
Bottom line
For most people, cold weather does not pose a serious threat to medications. Mail-order prescriptions remain safe in winter, and short-term cold exposure typically does not affect medication quality.
“If you have questions or concerns about a particular medication you’ve had delivered or are considering for future delivery, your pharmacist is a good resource,” Zuber said.
Besides your pharmacist, you can also talk with your primary care provider (PCP) about your medications. They can best address your questions and concerns. If you do not have a PCP, Medical Mutual can help. Use our Find a Provider tool in My Health Plan portal or call the Customer Care number listed on your member ID card.
The material provided, including websites and links, is for your information only. It does not take the place of your doctor’s advice, diagnosis or treatment. You should make decisions about your care with your doctor. What is covered by your plan will be based on your specific benefit plan. Providers quoted may not be in all Medical Mutual provider networks. Be sure to verify the provider is in your plan network if you want to schedule an appointment.