Apparently it's not as easy as it would seem.

https://idahocapitalsun.com/briefs/in-idaho-ivermectin-can-be-sold-over-the-counter-after-gov-little-signs-bill/

"Pam Eaton, CEO of the Idaho Retailers Association which represents Idaho pharmacies, testified in Senate committee that without an over-the-counter label that includes information like drug interactions, Idaho pharmacies largely can't sell ivermectin over-the-counter."