We generally advise against purchasing supplements by mail during very hot weather, as high temperatures can damage probiotics, vitamins, and phytochemicals found in herbs.

Ubiquinol is naturally produced in the body, so it can certainly withstand temperatures in the high 90s Fahrenheit. Exposure to higher temperatures will hasten degradation, but the process takes time. For example, an experiment with CoQ10 (a compound similar to ubiquinol) found a loss of only 15% after two months of being exposed to a temperature of 131 Fahrenheit. However, the addition of antioxidants, such as ascorbic acid (vitamin C), could minimize the loss to less than 5% (Kommuru, Chem Pharm Bull, 1999). Ubiquinol and CoQ10 products generally include antioxidant ingredients.

At a temperature of over 140 degrees, the gelatin in softgels can melt and this heat can also damage ubiquinol and CoQ10. If a break occurred in the softgel shell, exposure to air would speed degradation of the ingredient due to oxidation.

Since your softgels didn't melt and it is likely that the product may only have been exposed to high heat for a period of hours or days during transport, there was probably little degradation of the ubiquinol and it should be potent. To extend its shelf-life, store it at room temperature and away from light if it is in a clear bottle. 

For more information, including's tests and comparisons of products, see the CoQ10 and Ubiquinol Supplements Review.

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August 2, 2017

No one knows this better than the big vitamin e-tailers. Ever notice how their best discount offers always arrive during the hot months? There's a reason!
The interior of a UPS/FedEx/USPS truck exposed to a few hours of summer sun can go way over 100 degrees F. Will never forget one clear summer day opening a midday UPS delivery and how HOT the bottles were. "This can't be good," I thought.
Since then we buy a year's worth of everything during the winter months and store it ourselves.

April 25, 2018

Thanks for your post.

August 2, 2017

You mentioned the effect of heat on CoQ10. I'd be interested in a list of other supplements that are vulnerable to heat exposure. Thanks, and keep up the great work, CL.
August 2, 2017

Thank you Alan! Please see this CL Answer about the effects of heat on other types of supplements:

Ken 15344
August 2, 2017

Thank you for this information and, generally, for this sort of information. I've come to lean on you folks for the best available knowledge on matters regarding foods and supplements.
August 2, 2017

Thank you for your kind words, Ken!

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