Almost everything the world knows about how cannabis works begins with one Israeli scientist. Raphael Mechoulam — widely called the "father of cannabis research" — spent six decades at the Hebrew University of Jerusalem turning a stigmatised plant into a serious field of medicine. His story is, to a large degree, the story of why Israel sits at the centre of cannabis science.
This guide is informational and is not medical advice.
From Bulgaria to Jerusalem
Mechoulam was born in Sofia, Bulgaria, on 5 November 1930, to a Sephardic Jewish family, and immigrated to Israel in 1949. He earned his doctorate at the Weizmann Institute in 1958 and later moved to the Hebrew University of Jerusalem in 1972, where he would spend the rest of his career (Wikipedia). He died at his home in Jerusalem on 9 March 2023, aged 92 (Journal of Cannabis Research tribute, PMC).
Isolating THC (1964)
His foundational breakthrough came in 1964, when, working with Yechiel Gaoni at the Weizmann Institute, he first determined the exact chemical structure of delta-9-tetrahydrocannabinol (THC) — the plant's main psychoactive compound (Wikipedia). The origin story has become legend: lacking a legal supply, Mechoulam obtained five kilograms of Lebanese hashish from the Israeli police and carried it back to his lab by bus. That this was possible at all reflects a recurring theme — the Israeli state treated cannabis as a legitimate object of study decades before most countries did.
Discovering the body's own cannabinoids
Mechoulam's second great contribution was arguably bigger than the first. In 1992, his group discovered the first endocannabinoid — a cannabinoid the human body produces itself — which he named anandamide, after the Sanskrit word ananda, meaning supreme joy or bliss (Wikipedia). The discovery showed that cannabis doesn't introduce an alien mechanism into the body; it acts on a signalling system humans already have. That insight opened the entire field of endocannabinoid medicine.
The legacy
Mechoulam is remembered not only for specific discoveries but for legitimising a whole science. He trained generations of researchers, co-developed the concept of the entourage effect, and gave Israel a head start in cannabis research that the country still trades on. The institutions that now define Israeli cannabis science — above all the Hebrew University's research centre — grew directly out of the path he cleared. For that broader ecosystem, see our guide to Israel's cannabis research institutions.
His career is the single clearest reason a small country became, and remains, a disproportionately important place in global cannabis science. For more on that scientific heritage, see our Research hub.
Compiled and reviewed by Tamar Levin, Editor. Sources are linked inline. This guide is informational and is not medical or legal advice; consult a licensed physician about your own treatment.
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