Cordyceps' active compound breaks down fast once it is inside you
Cordycepin, the compound the marketing rests on, is taken apart by an enzyme your body already makes, leaving it a short half-life and low bioavailability.
What the study found
An enzyme you already carry takes cordycepin apart quickly
Cordycepin is the compound marketed as the reason cordyceps works. Adenosine deaminase, an enzyme your body already runs, leaves it a short half-life and low bioavailability. In authentic wild material it starts at 0.0076 to 0.029 percent by weight.
The caveat · No human half-life figure given
The pharmacology paper is a review and reports no human half-life figure. Its interest is in engineering cordycepin into something usable, with an enzyme inhibitor, a redesigned molecule or a new delivery system, none of which exists in a capsule. And it never asks the separate question of whether the amounts in a supplement would matter even if they did survive.