Bio-sil caused me to have really bad pains in my arthritic ankle. I've experimented with it a few times and after a week or so the pain starts up. I've no idea why as cogimax or other silica supplements don't do that.
You would never know i've got a serious ankle problem as other than some scar tissue swelling as I rarely limp or have any problems. On the bio-sil the pain was bad enough I was limping and using a cane within a week.