I called Select the Best customer service to simply inquire where the M S M is manufactured. The lady that answered was very defensive and very rude, stated that they don't give that information. I asked to speak to someone else, and the "head" of customer service was extremely rude and defensive also. He answered that it is made in the US, so I said that it is helpful if that is printed on the label. I also informed him that the lady was extremely rude and defensive and he was very rude and defensive about her. THIS LEADS ME TO BELIEVE THAT MAYBE THEY ARE NOT TELLING THE TRUTH! A product that is made in the USA would be a positive feature to brag to customers. I DO NOT want to buy any of their products anymore, based on the way I was treated. I asked a simple question in a kind manner, all I needed was a simple answer. Kind of ruins your morning to be treated like crap and have already supported that company. Good customer service DOES MATTER!