“States should be using 21 U.S.C. § 822(d) to bring therapeutic use of cannabis into compliance with federal drug law”

See 2020 Iowa Acts ch. 1116, § 31 for Iowa’s feeble attempt (DEA hasn’t responded)

The authority for religious use of controlled substances comes from 21 U.S.C. § 822(d).  See 21 C.F.R. § 1307.31 (religious use of peyote)