2014
- Governor Jay Nixon signed House Bill 2238 – the Missouri Medical Marijuana Bill – to legalize the use of CBD oil to treat persistent seizures. HB 2238 only allows hemp extract that contains at least 5% cannabidiol (CBD) and no more than 0.3% tetrahydrocannabinol (THC).
2018
- Amendment 2 Medical Marijuana and Veteran Healthcare Services Initiative - this amendment was approved in November 2018 with 66% of the vote. It legalized marijuana for medical purposes and allowed physicians to recommend cannabis use to patients based on the listed conditions.
2022
- Missouri residents voted yes on Amendment 3 during the November 2022 election, legalizing recreational marijuana possession and use in adults at least 21 years old. The new law will also allow non-incarcerated individuals with non-violent marijuana charges to have their records reviewed and possibly have their convictions expunged.
In addition, the amendment adds several new benefits for medical marijuana cardholders:
- Medical marijuana cards are now valid for three years instead of one.
- Monthly medical cannabis allotment increases from four to six ounces.
- Employment protections to prevent discrimination if medical cannabis is used during non-work hours away from the worksite.
- Missouri residency is no longer required to apply.
- Nurse practitioners can now certify patients.
- The cost to apply to grow cannabis will decrease from $100 to $50.
- As of December 8, 2022, consumers are allowed to possess up to three ounces of marijuana but won't be able to purchase it without a medical card in a dispensary until the state issues licenses, expected sometime in 2023.