Alexis Bortell, 12, is suing US Attorney General Jeff Sessions over the US' marijuana policy.

Bortell's family moved to Colorado so that their daughter - then 10 - could access medical marijuana, a treatment that's illegal in her home state of Texas.

Bortell was diagnosed with epilepsy at a very young age. She suffered daily seizures. Staying in Texas, her only options were an invasive brain surgery, or accepting the recurring seizures. A pediatrician eventually mentioned the out-of-state option: medical marijuana.

After moving to Larkspur, Colorado, Bortell started a therapy of cannabis oil called Haleigh's Hope. Two drops of THC per day kept the seizures at bay.

The treatment has been effective for more than two years, and Bortell judges it, "a lot better than brain surgery," she told Rolling Stone.

"It's helped me succeed in school more, since I don't have to go to the nurse every day because of auras and seizures," she added.

However, the current marijuana laws keep her from traveling anywhere while carrying the drug, and especially from going back to Texas. "I would like to be able to visit my grandparents without risking being taken to a foster home," she told Rolling Stone.

That's the reason why the teen and her parents have joined four other plaintiffs in a lawsuit that aims to legalise medical marijuana at the federal level. Alexis joins another child, a military veteran, a marijuana advocacy group and former Broncos player Marvin Washington as plaintiffs.

"This is a civil rights case that focuses on the rights of individuals using life-saving medication to preserve their lives and health," said Bortell's attorney, Michael Hiller.

According to him, the Controlled Substances Act - CSA - that classifies cannabis as an illegal substance expands to various constitutional rights.

Hiller and co counsel Lauren Rudick, Joseph Bondy, and David Holland filed a complaint against United States District Court for the Southern District of New York.

The defendants are the defendants — Jeff Sessions, the Department of Justice, Chuck Rosenberg, acting director of the Drug Enforcement Administration, the DEA itself and finally, the United States of America.

So far, only 29 states have legalised medical marijuana.

The federal government has lost its first motion to have the case dismissed.