Trouble with Lichen by John Wyndham

A "sharp, amusing story" (The Guardian) about the fountain of youth and its implications for women's rights, by one of the twentieth century's most brilliant--and neglected--science fiction and horror writers, whom Stephen King called "the best writer of science fiction that England has ever produced." 

What if humans discovered the secret to prolonged life?

 

Francis Saxover and Diana Brackley, two biochemists investigating a rare lichen, separately discover that it has a remarkable property: It slows the aging process almost to a halt. Francis, realizing the horrifying implications of an ever-youthful wealthy elite, decides to keep his findings a secret. But the younger and more daring Diana sees an opportunity to overturn the male status quo and free women from the career-versus-children binary--in short, a chance to remake the world.