Adrenochrome Has Vendors but no Uses?

Straight from the NIH.gov website, the Adrenochrome page at the National Library of Medicine has a list of several vendors for adrenochrome, but no information on what adrenochrome is used for. A search turns up nothing as well, although Wiki says there are "no current applications" for adrenochrome. Why would we need so many vendors if it's not being used for anything? Was it ever used for anything that they can tell us about without being in a $*&^load of trouble for?