After trying many over-the-counter medications for knee pain, I saw this advertisement for Instaflex Advanced and decided to give it a try. I ordered it online from Walgreens, two for one, 14 pills in each bottle. I took it for about 10 days and did notice some relief from pain, however, on the 11th day started to experience severe diarrhea and vomiting, to the point that I had to go to the emergency, and found out that an ingredient in this pill was the problem and caused a bad bacteria infection. So if you are going to take this pill, please check with your primary care doctor to make sure you can take this med. I am not saying it does not work, but everyone should make sure before taking it.
Bottom Line: No, I would not recommend this to a friend