I'd forgotten about the other claims but in general don't put too much trust into supplements either, I'm taking a bunch of them and if they have any effect it is a very mild one. Also supplement prices are 2 to 3 times higher than in the US over here, usually they cost more than related medication which gets ridiculous.
I'm still not about to stop anyway and a couple of them see to have a noticeable effect, including hyaluronic acide for meniscus degeneration, but it might be something else that helps, like squatting 3 times a week. Dunno. Now also use it with chondrotin and glucosamide sulfate. Another very helpful although less sexy supplement is hesperedin/diosmin (it's also sold as an otc drug, usually named daflon), without it I easily get itchy butt or worse, but with it hardly any issue.