The US chemist known as the father of the birth control pill has died at his San Francisco home aged 91.
Carl Djerassi, the chemist widely considered the father of the birth control pill, has died.
Stanford University spokesman Dan Stober says Djerrasi died on Friday of complications of cancer at his San Francisco home. He was 91.
Djerassi was a professor emeritus at Stanford but most famous for leading a research team in Mexico City that in 1951 developed norethindrone, a synthetic molecule that became a key component of the first birth control pill.
"The pill" as it came to be known radically transformed sexual practices and women's lives.
In his book, This Man's Pill, Djerassi said the invention also changed his life, making him more interested in how science affects society.
Later in life, he wrote poems, short stories and plays.