Getting on in one's years, one finds that resistance and/or impact training requires some joint fortification. Glucosamine + chondroitin has been my go-to supplement, despite the lack of indisputable statistical evidence from well designed studies. I find that things generally tend to improve a few months after taking them, though by no means does it eliminate joint problems.
My issue is the inability to vet sources with any degree of confidence to ensure that the chondroitin component comes from shark products rather than cow products. Quite apart from my inability to check the veracity of claims, it's also quite hard to identify products that ostensibly meet my criterion. For example, I found one very niche product that says the chondroitin is from shark, but then says that the supplement comes in gelatin capsule. Which is made from ...(guess what) ???
I was completely baffled by why a vendor would go to the trouble of having the chondroitin component come from sharks, then undermine the whole effort by encapsulating the product in gelatin. Sure, most buyers probably wouldn't realize that gelatin comes from bovine products, but the vendor sure as heck knew. I got the impression that they didn't fully understand the general concerns in play, and just wanted a product that checked off the boxes of consumer concerns as far as the vendor could superficially identify them.
Anyway, if anyone is aware of something from a reputable source that avoids bovine products, thanks if you can chime in. I realize that there are "threats" to product and supply chain security, such as counterfeit goods (especially ordering online) so I intend to buy either directly from the manufacturer or to first verify with the manufacturer that a vendor on (say) amazon is really them.