@jozer I tried collagen well-researched supplements for an entire year, and saw no difference in skin, hair or nails. I do not have osteoporosis or even osteopenia, but have a strong family history of it, so I hoped it might help there too. My DEXA at the end of that year showed no change from 2 years prior, so probably no help there either.

As your primary told you, these supplements are unregulated, so we can only hope they contain what is promised (and nothing more). After a year of no particular benefit, I decided it was a failed experiment and quit.