The nerve-repair research is all laboratory dishes and animals
A search of three databases from 2010 to 2024 returned 11 papers on mushrooms for nerve repair, five of them lion's mane. Every one was laboratory or animal work.
What the study found
Eleven papers on nerve repair, none of them in a person
A search of three databases for mushrooms used to repair damaged nerves in the limbs, 2010 to 2024, returned eleven records across four species. Five concerned lion's mane. Every one was laboratory or animal work; the reviewers' conclusion was that clinical research still needs doing.
The caveat · Several come from one research group
The review's verdict that lion's mane is the most promising of the four is a ranking inside eleven papers, partly earned by having the most of them and by being safer than fly agaric. Several of those five come from one research group, so they are less independent than the count suggests.