Hi LMT! Yes, I've used that product. I usually only use it when the kids at school are starting to get sick. Something to help boost my immune system..I've had no problems with it. Oh! And I used to take it when my wrist pain would flare up...My wrist was damaged in a car accident. I didn't even realize it at the time. It happened when I placed my hand on the dash when the driver braked suddenly. We avoided the accident, but my wrist was a little tender. Then about a year later, my wrist started to hurt whenever it would get really cold, and my wrist had limited mobility. So I talked to my doc. (GP) and he said he could prescribe me something, but if it was damage due to bracing my fall, then it was going to be a long term issue. So I asked if there was anything else I could use...you know, not a prescription. He said to try 1000 mg. of vitamin C and MSM (for a week at a time, then after that, only as needed. ). I tried it...and it worked. Every once in a while my wrist gets stiff, but no pain..and the stiffness goes away if I get my vit. C and MSM.