Probiotics, a popular form of health supplements, contain live organisms, so proper refrigeration can be crucial to their effectiveness, according to ConsumerLab.com, a company that tests supplements.

In a question-and-answer section of its website, Consumer Lab.com wrote that moisture can activate probiotic bacteria that come in the pill form, and heat can kill the organisms. Freeze-dried probiotics that are appropriately packaged to prevent moisture generally don’t need refrigeration and have a longer shelf life than supplements containing live organisms, such as liquid products, which must be refrigerated.

Read labels for directions, and when in doubt, refrigerate, ConsumerLab.com wrote. Ensure that the retailer refrigerated products that require it. And when ordering probiotics by mail, have them shipped overnight or with refrigerated shipping.

When Consumer Lab.com tested probiotics in 2009, 85 percent of the products tested didn’t contain the listed amount of organisms. ConsumerLab.com said that it later learned that improper shipping and warehousing might have been partly to blame because in 2012, when refrigeration techniques had improved, only 17 percent of products failed testing.

— Anne Aurand, The Bulletin