DENVER Medical marijuana now comes with the FDA seal of approval.

On Monday the agency approved its first marijuana-derived drug , Epidiolex , for the treatment of Lennox-Gastaut syndrome and Dravet syndrome, two rare forms of pediatric epilepsy .

The oral solution contains cannabidiol, or CBD , a nonpsychoactive compound that has proved beneficial in reducing the catastrophic, potentially life-threatening seizures that accompany both conditions.

In clinical trials , children with Dravet syndrome who took Epidiolex experienced 39 percent fewer seizures; those with Lennox-Gastaut syndrome saw a 37 percent decrease.

In a statement accompanying Mondays approval announcement, the FDA hastened to note that its not signing off on the safety or medical utility of marijuana in general just this one compound and only for this limited use.

Its also important to note that this is not an approval of marijuana or all of its components, said Dr. Scott Gottlieb , the FDAs commissioner. This is the approval of one specific CBD medication for a specific use. And it was based on well-controlled clinical trials evaluating the use of this compound in the treatment of a specific condition.

He added, This is how sound medical science is advanced.

Critically, the drug will be available to patients nationwide, not just in states where cannabis is legal for medical purposes.

While there was initially some confusion about whether the Drug Enforcement Administration might block the sale of Epidiolex, given cannabis status as a Schedule I substance, Epidiolex manufacturer GW Pharmaceuticals doesnt believe that will be the case.

Thats according to Steve Fox, the director of VS Strategies, which was retained by GW Pharmaceuticals to assist with public relations and cannabis industry outreach efforts.

The DEA will not prevent Epidiolex from being sold, Fox said Monday. The role of DEA at this point is to be involved in determining the appropriate schedule for Epidiolex. But as far as I understand it, they dont even have the power to block it at this point. They just determine what schedule it will be.

GW Pharmaceuticals manufactures another cannabis-derived drug, Sativex , which helps treat muscle spasms from multiple sclerosis. Sativex hasnt been granted approval in the United States, however.

Fox hailed Mondays FDA action as a win for the broader medical marijuana community, in that it will facilitate more clinical research into the drugs medical benefits. Whats more, the DEA will reportedly reschedule CBD in light of the FDAs decision, greatly loosening restrictions on research.

For medical marijuana advocates, its a clear vindication of a fundamental premise of a decadeslong movement: that cannabis can have legitimate medical applications and it isnt the bogeyman that the federal government has long made it out to be.

For a maligned substance like cannabis, I think the vindication tour will ultimately be years long, said Ricardo Baca , a former marijuana editor at the Denver Post, and the founder of Grasslands , a cannabis PR agency.

Ultimately this process will take years, but this is a historic day, without a doubt.