Israeli chemist Raphael Mechoulam spent decades unlocking the mysteries of marijuana in a lab, but his fascination with one of the world’s most popular drugs never led to personal experimentation, he said in a recent interview.

“I have never used it,” Mechoulam told Culture Magazine earlier this month. “First of all, I am still interested, but as I did research and we had [an] official supply of cannabis, obviously if we had used it for non-scientific reasons, if people had come to know about it that would have stopped our work. Basically, neither I nor my students were interested.”

Ethical self-restraint is just a small part of Mechoulam’s story. His research into the pharmacology of cannabinoids began in the early 1960s with a batch of hashish that police passed to him out of an evidence locker.

Over the next few years, his group would become the first to isolate and synthesize cannabidiol, or CBD, now revered for its potential medical applications, as well as tetrahydrocannabinol‎, or THC, the psychoactive compound in marijuana that makes users feel high.

Mechoulam’s work also opened the door for more recent developments in the field of marijuana medicine. Studies have shown that cannabinoids have promise in the treatment of ailments including cancer, epilepsy, chronic pain, anxiety and even some psychotic symptoms.

There appears to be a bright future for the research Mechoulam pioneered, especially in Israel, where marijuana has been legal for medical purposes since the 1990s.

Although a total of 28 U.S. states have legalized marijuana for medical purposes ― and eight states and Washington, D.C., have approved it for recreational use ― it remains illegal in the country at the federal level, which has complicated U.S. scientific research efforts. Israel, on the other hand, has embraced a role as a leader in marijuana research.

In 2012, Israeli researchers were among the first to successfully breed a marijuana plant that contained no THC but high levels of CBD. Earlier this year, the nation began considering steps to decriminalize marijuana use and allow export of medical marijuana products.

Mechoulam is officially retired now, but he believes there’s still plenty of work to do to fully uncover the therapeutic potential of the compounds he discovered more than 50 years ago.

“There have been very, very few clinical studies,” he told Culture. “Although thousands of people use cannabis to fight cancer, there hasn’t been any clinical study, or a well-done, modern clinical study on cancer published. That’s a shame because if people use it, the data should be there. We should have modern clinical data.”