Q. I remember reading in your column that heat can be bad for medicines. Since I don’t take any drugs I didn’t pay any attention.

Yesterday I received a delivery of vitamins and herbs. The temperature outside was over 95 and it must have been well over 100 in the back of the delivery truck since my package was so warm.

Can heat ruin vitamins or herbs such as ginkgo, St. John’s wort or saw palmetto?

A. Heat and humidity can degrade many compounds, natural as well as synthetic. Manufacturers recommend that most pharmaceuticals be stored at room temperature, between 68 and 77 degrees Fahrenheit. Brief temperature spikes to 86 degrees are considered acceptable.

We have long been concerned about mail order services that send medicines in trucks without air conditioning. Summer shipments to pharmacies may pose a similar problem. Temperatures in delivery vehicles can easily rise to over 120 degrees.

Herbs and vitamins are probably not immune to such heat. Cooks know that herbs used to flavor food should not be exposed to heat or they lose their potency. If you’re planning to order more herbs in August you may wish to delay until the heat abates.

Anyone who receives prescription drugs through the mail should also recognize that heat and humidity can be the enemies of your medicine. This is especially true for liquids like insulin. Make sure your mail-order pharmacy takes this into consideration.

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    Medication providers such as V.A. send perishable drugs such as insulin in refrigerated containers with ice packs inside–other mail order companies should follow suit for safety and keeping the drug(s) fresh and up to strength.

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