For the first time, the Food and Drug Administration has given its approval for a cannabis-based medication that will be available in all 50 states.
Epidiolex is an oral solution officially approved for treating people with two types of epileptic syndromes.
Dravet Syndrome, a rare genetic dysfunction of the brain that begins in the first year of life and Lennox-Gastaut Syndrome, a form of epilepsy that usually emerges between the ages of three and five.
Doctors are also allowed to prescribe Epidiolex for other conditions.
The medication was recommended for approval in April and approved by the FDA in June.
In September, the DOJ and the DEA classified it as a schedule five substance, clearing the final hurdle for it to be legally prescribed by doctors in the U.S.
It is approved for use in patients aged two years and up.
GW Pharmaceuticals says the average list price of Epidiolex is $32,000 a year and most insurance plans will cover the drug.