THIS . As a runner, I can tell you, it WORKS!! I had a 10 day trial that was given to me, within 3-4 days I could tell a HUGE difference. Once my 10 day trial was over, by day 5, I could tell I was no longer taking it. What a difference this supplement made. My knees ache from time to time, and more so when we run in the foothills. I mentioned this to my Dr and he recommended Membrell to me. I take it once a day in the PM. Tell him he will feel like a brand new man in just 10 days I take this in addition to MSM, Glucosamine and Chondroitin. I am sure you can find other brands, this is just the brand that I take.