“No matter what we did, nothing helped. She just got worse until she was almost a vegetable,” he said. “She had no chance at life.”

Then in July, he and his wife, Miriam, saw an online video of a Colorado Springs girl’s astounding recovery from epilepsy using an oil made from a special strain of marijuana. The Halabis live in New York City, where medical marijuana is illegal.

“As soon as we saw it, we knew we had to go,” he said.

Families of children with severe medical problems are moving to Colorado from all over the country to get the oil that appears to be working. They call themselves marijuana refugees.

“These families are really desperate,” said Dr. Margaret Gedde, a Stanford-educated Colorado Springs pathologist who has recommended many of the arriving children for medical marijuana. “They’ve tried all the drugs, and nothing has worked. This is the only option left.”

Repeated studies going back to 1970 have shown a strong potential for cannabidiol to help epilepsy, but federal laws made cannabis difficult to study in the United States. In addition, there is a stigma in the medical field.

While pharmaceutical grade cannabidiol is available in other countries, clinical trials for FDA approval in the United States are just getting underway.

In to 2012, a 5-year-old girl named Charlotte Figi who has a genetic disorder called Dravet syndrome that causes catastrophic seizures, was given a new chance at life from marijuana . Doctors tried everything from barbiturates to extreme diets to control the disorder, but nothing helped. She was in the hospital constantly. Twice her heart stopped. Not wanting to prolong their child’s suffering, her parents signed a “do not resuscitate” order.

As a last-ditch effort, they decided to try marijuana, and it worked.

Experimenters developed a new strain of marijuana that was exceptionally low in THC—the chemical that makes users stoned—and exceptionally high in a chemical called cannabidiol that has no intoxicating effects, but that a handful of decades-old studies suggested might reduce seizures.

The original developers called it Hippie’s Disappointment, because no one wanted to buy it. They have since renamed it Charlotte’s Web after a girl who once had 300 seizures a week and now has on average fewer than one.