is exposed to air? Do you suggest taking metformin together with DCA? Q: Hi. How long can I use DCA after the package has been opened? Does it go out of date quickly when it is exposed to air? Do you suggest taking metformin together with DCA? Thanks, Kristina. A: Hello, dear Kristina. You should try looking for the expiration date on the package of the product you purchased. Typically, if DCA doesn't gather moisture inside, it can be kept for a few years. This is why we advise you to store it somewhere cool. Make sure that the bottle is tightly sealed at all times. Also, the question regarding storage is answered with details in this article: https://www.dcaguide.org/dca-dosage-and-usage-long-guide#How%20to%20store%20DCA? We have observed using metformin + DCA for some time now, it seems that the combination work quite well together. For example, look at this study: Dichloroacetate and metformin synergistically suppress the growth of ovarian cancer cells. Nevertheless, don‘t overdo metformin (not more than 500 mg or 1000 mg daily if you don‘t have diabetes). Also, avoid metformin if you have kidney diseases. If you can‘t tolerate metformin, you can try a natural alternative that has some of its benefits – berberine.