How Temperature Can Affect Medication Stability

It's recommended that most over-the-counter and prescription medications be stored at what's known as "controlled room temperature." That's about 77 degrees F, on average. Medications are manufactured under very strict specifications, and, whenever possible, these products are designed to remain stable at room temperature.

The active chemicals in any medication can change in molecular form when exposed to different temperatures, potentially resulting in decomposition of the medication. This decomposition can make medications less potent and may even result in new or different effects.

Recommended Medication Storage Temperature

Some medications are more stable than others. Most remain at their most stable if they are transported and stored at room temperature.

Many medicines can be maintained in temperatures as low as 52 degrees F, such as the liquid form of the antibiotic amoxicillin, or interferon beta, which is used for the treatment of multiple sclerosis. A few medications can even maintain their composition if they are frozen.

There are no medications that can be stored at temperatures above 86 degrees F, since hot temperatures tend to degrade most formulations.

For this reason, storage and transport of medications in tropical climates require extra care and attention.

Some medications that have to be stored at room temperature can tolerate what is known as "controlled excursions"—short periods to accommodate necessities such as shipping—at temperatures up to 86 degrees F.

Some examples of medication storage recommendations:

  • Lipitor (atorvastatin calcium) for treatment of high cholesterol: Room temperature
  • Toprol (metoprolol succinate) for treatment of hypertension and heart failure: Room temperature; between 59 degrees and 86 degrees F for excursions, if needed
  • Norvasc (amlodipine besylate) for treatment of high blood pressure: Room temperature
  • Synthroid (levothyroxine) for treatment of hypothyroidism: Room temperature; between 59 degrees and 86 degrees F for excursions, if needed
  • Veletri (epoprostenol) to treat pulmonary hypertension: Between 35.6 and 46.4 degrees F

Compounding Pharmacies

If you are getting your medication from a compounding pharmacy, your healthcare provider has prescribed you a specific formulation that is not readily available. These medications are prepared individually for each person, not in high volume like most commercial drugs. Pharmacists must follow strict protocols. Often, especially with liquid or injectable compounds, these formulations require restrictive storage and transport temperatures, and may not last as long as most medications.

Factors That Alter the Temperature of Your Medications

There are a number of factors that can expose your medications to dangerously high temperatures.

  • Hot weather: If you don't have air conditioning (and keep it on 24/7 during hot spells), high outside temperatures can cause your home to become warm enough that medications "overheat." This is a particular concern during power outages.
  • Car: Storing your medicine in your car for an extended period of time can expose it to high heat.
  • Travel: Your medication may sit in your luggage on a hot tarmac or in non-air conditioned luggage handling areas.
  • Pharmacy: If your pharmacy loses power for an extended period of time before you picked up your prescription, you may be unaware of the problem.
  • Delivery: If you get your medicines from a mail-order pharmacy, they could be delivered in a non-temperature regulated truck or may sit in your mailbox for an extended period of time.
how to protect your medication
Illustration by Emily Roberts, Verywell 

How to Protect Your Medication

You can take some steps to prevent heat-related degradation of your medications.

  • Check the storage information for any medications you take so that you are aware of the temperature recommendations.
  • Carry medications on the airplane with you, instead of storing them in your checked luggage. Your security and customs check-in will be more efficient if you travel with your medicines in their original containers with pharmacy labels.
  • Do not store medications in your car or trunk for extended periods. Take them with you when you leave your car.
  • Ask your pharmacy if they have an emergency generator to maintain temperature control for refrigerated medications.
  • If you have the option, order any of your mail order prescriptions in temperature controlled packages. Have mail-ordered medications or internet pharmacies ship to you by overnight delivery methods, and be there to accept packages.

What to Do If Your Medication Has Been Exposed to Excessive Heat

If your medication has already been exposed to high temperatures, talk to your pharmacist to see if you need to replace it.

Your next step should be a call to your health insurance company or HMO, who may be able to replace your medication at no cost or reimburse you for a replacement prescription.

Finally, if your pharmacy and insurance company are unable to help you, contact the manufacturer through the consumer hotline. Many manufacturers will allow you to return the medication in exchange for a replacement with a new batch.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

By Mary Shomon
Mary Shomon is a writer and hormonal health and thyroid advocate. She is the author of "The Thyroid Diet Revolution."