I have used Swanson's Glucosamine, Chondroitin and MSM with Hyal-Joint for many years.
In order to determine the effect of Instaflex, I stopped taking the Swanson product for two weeks before starting Instaflex.
Here are the results of my trial period:
A. I took the Instaflex exactly as the customer service rep said to take it.
B. I started to have mild consistent pain in my knees at all times. On a level of 1 to 10, this was a 2 to 3.
C. When I played tennis, I started to get much more pain after about an hour. This reached a 6 to 7 level each time that I played. The pain would remain well into the evening.
D. After the trail, I went back to the Swanson product, and after a few days, the consistent pain was gone again. When playing tennis there is only a mild pain (level 4-5) when a wrong twist is made, but it goes away in a minute or two.
This product made my pain worse, but maybe it will work better for you.
Bottom Line: No, I would not recommend this to a friend