well, okay, oak bark is how it all began... so, maybe oak bark extract and oranges
or lemons(for a natural occurance of the C) would do as much or more. If I were you, I'd look beyond the 'product' to the source.
Herbs are food, whereas 'supplements' as sold in this manner, are more like 'standard drugs', or 'meds': unnecessarily complicated -- ( which has the effect of making people feel it's all 'beyond them'; making them feel somehow 'small' and in need of being made 'bigger'. This is something the ego has endlesss time for because it is an attack on the self that is NOT small, has nothing to do with ego and is NOT separate from inherent wholeness, except through abandoning it.) Such supplements (while fine, even perfect at the 'source level') are not so much different than, say, salt being stripped of all its minerals; the minerals sold to make 'supplements' and the now-denatured so-called 'salt' (with sugar added!) sold back to an oblivious and trusting public, who are now being told that 'salt' is dangerous. And who are now hooked into the sugar-salt seesaw. And-- another cycle of the need to return to wholeness begins. Uhm. yeah, thanks!
so, that's what "I" think -- however I know that some people seem to respond well to something that IS a product; packaging, promo, studies on pigs,"for six weeks or so" etc. It's like having 'nice things'. Having it done for you.( being small and feeling big) Maybe it CAN do some good, of course it can, maybe there's enough of the oak bark in there to effect a noticeable change, but here (this forum)people are more on about addressing the roots of things, not so much the symptoms. That said, everyone will start where they can. And do the best that they are able.