The chemist who reinvented the popular party drug ecstasy has died at the age of 88 from liver cancer.
Alexander Shulgin earned his nickname, the Godfather of ecstasy, after honing a way to make the drug - and testing it out on himself to check it had worked.
A Facebook post by his wife and research partner, Ann, said he died "surrounded by family and caretakers and Buddhist meditation music".
He lived out his final years at his home in Northern California.
Shulgin began his study of organic chemistry at Harvard University in his teens and, after a stint in the US Navy during World War Two, returned to Berkeley to get his PhD in biochemistry at the University of California.
In his early working career, he joined Dow Chemical Company and, while there, developed the world's first biodegradable pesticide.
But it was while he was pursuing his own research that he began experimenting with psychoactive compounds.
He tested out his new creations on himself, inviting small groups of friends to join him in the tasting sessions.
During the swinging '60s, he says he made and tested hundreds of concoctions.
In 1965, he parted company with Dow, but continued his studies and began teaching classes at local universities.
Nearly a decade later, he came across a compound closely related to what we now call ecstasy or MDMA.
MDMA had been previously synthesised and patented in 1912 by the pharmaceutical company Merck, but was never fully explored within humans.
Shulgin decided to start human trials - again, starting with himself.
Once he had fine-tuned his recipe, he introduced the chemical to a psychologist from Oakland called Leo Zeff.
And Zeff introduced Shulgin to a lay therapist called Ann, who later became Shulgin's wife.
Zeff used small doses of the substance in his practice as an aid to talk therapy, and introduced it to hundreds of psychologists across the nation.
Clubbers have been known to use ecstasy so they can dance for hours. In some cases, people have died from taking ecstasy.
The drugs advice charity Frank says a big problem with ecstasy is that it's rarely pure.
"Regardless of what it looks like and what it is called, you can't be sure what's in a pill or a powder and you can't predict how you'll react," it advises.
Prof David Nutt, professor of neuropsychopharmacology at Imperial College London and a former government adviser, said fewer young people might have died from recreational drug toxicity if society had "listened and learned from Shulgin rather than tried to suppress his knowledge and ideas".