This is incredibly common with things such as fungi, which are known to have numerous benefits across a wide body of studies. The catch is that most of the supplements are just filler, leftover parts you can't use for much else e.g. ground up stem or even growth medium that has little to nothing in it.
Take this with a grain of salt and consider that my source sells supplements but I first heard about this on nootropic depot. Looking on other reputable vendors, they do seem to include fruiting body and mycelium. Supposedly, ND only does the fruiting body. Now is that better? Haven’t gotten that far independently but they have a write up.
I’m not paid by them, and think they overcharge, but the internet seems to trust them (but they have a lot of guerilla Reddit marketing on their subreddit). Maybe this info will save someone time.
