4 evidence-graded facts. Click any card for the full summary and sources.
Raphael Mechoulam's team in Israel isolated and synthesized Δ9-THC in 1964 — and CBD a year earlier. Despite cannabis being used for millennia, its chemistry is a modern discovery: younger than the Beatles.
THC STRONG EVIDENCETHC partially activates CB1 receptors rather than fully switching them on. This partial activity is one reason cannabis has a wide safety margin compared to full-agonist synthetic cannabinoids ("spice"), which can be lethal — a critical distinction often lost in public debate.
THC STRONG EVIDENCEUS potency-monitoring data shows average THC in seized cannabis rising from ~2% in the 1970s–80s to well above 12–15% in recent years, with concentrates reaching 60–90%. "Cannabis today" and "cannabis in the studies from 1985" are not the same exposure.
THC STRONG EVIDENCEEaten THC passes the liver first, where it converts to 11-hydroxy-THC — a metabolite that crosses the blood-brain barrier more efficiently and is more potent per milligram. This is pharmacology, not imagination, and why the same milligrams hit harder eaten than smoked.
THC