I do have bad knees, so I have taken the tablets you mentioned. I didn’t feel a noticeable difference one way or the other. I still have a bottle of the stuff sitting in my bathroom. I’ll start taking it again someday. If you do decided to start taking it, I’d suggest getting it from Coctco, it’s much cheaper. And, be sure to check how many milligrams of the stuff are in each pill, you may end up having to take four a day if you don’t.
I’m old (see avatar box) and my left knee cartilage has a small tear in it that I’ve been nursing since High School football (32 years ago). I tried Glucosamine Sulfate and Condroitin, you have to give it 4 to 6 weeks, which I did. It didn’t seem to do anything for me. But I can still do almost everything I want to, except that Samurai-style knee walking that us Aikido folks do.
I have used glucosamine and condroitin for several years. A few times I have run out and gone without for a couple of months, and every time I start having knee pain again. After a couple of weeks of taking it again the pain goes away. So for me, it does seem to work well. When you start taking it you take a higher dose for a while, then reduce it. You have to take the recommended amount for it to do any good at all, according to the doctors who agree that it works. It sure helps old dogs (the canine kind) get around also.