[3] While psilocybin remains illegal nationally, the passage of the law made Oregon the first U.S. state to legalize the drug.

The ballot measure put in place a two-year period for the government to determine regulations around the law's implementation, such as what credentials will be needed for someone to administer the drug.

[5] On November 3, 2020, Ballot Measure 109 was passed with support from 1.27 million Oregonians, or 55.75% of the vote (according to unofficial results from the Oregon Secretary of State in the days following the election).

In the 2022 midterm elections, however, a total of 102 incorporated cities and 25 counties in the state voted, temporarily or permanently, to prohibit psilocybin-related business from being conducted within specified areas.

[7] As of 2025, psilocybin therapy is permitted in the following counties: Benton, Clatsop, Columbia, Deschutes, Hood River, Jackson, Lane, Lincoln, Multnomah, Wasco, Washington, and Yamhill.