Myrtle Potter

By Chris Taylor/San Francisco

You've probably never met Myrtle Potter, but you may have taken some of the medicines she has marketed. At Merck in the early 1990s, her name became legend when she took charge of a struggling ulcer remedy called Prilosec and transformed it into a worldwide best seller. At Bristol-Myers Squibb in the late '90s, she worked the same magic on billion-dollar brands like Pravachol (for high cholesterol) and Glucophage (for diabetes). Today Potter, 44, is the COO of the world's No. 2 biotech firm, Genentech, where she's working to bring 20 drugs to market over the next decade. By then, observers believe, Potter stands a good chance of becoming a CEO.

Like the jeans and sandals she often wears to work, Potter's casual demeanor can be deceiving. Says Noel Tichy, a University of Michigan business professor who profiled Potter (along with CEOs like GE's Jack Welch) for his book, The Cycle of Leadership: "I've watched her with her people, and she puts them out of their comfort zone. She's not an easy person to work for if you don't want to be pushed." Yet "she never misses an opportunity to give the credit to someone else," says Claudia Estrin, a colleague of Potter's since 1989.

Growing up in a big family in Las Cruces, N.M., taught her teamwork. "Six kids in a two-bathroom home," she says. "If you don't work in shifts and make trade-offs, you can't get out of the house in the morning." Her father remortgaged the house to send her to the University of Chicago. A part-time job at the university hospital began a love affair with medicine, and an IBM internship drew her to business.

Counting experience over ambition, Potter spent her early career making lateral moves and rejecting promotion offers. In 1982 she visited Genentech's South San Francisco offices to interview for a lowly sales position. She didn't get it, went to Merck and never looked back--until two years ago, when Genentech wooed her with a million-dollar bonus.

Potter works long hours but puts her family first. When her son, 16, was 3, she learned that he had a developmental disability. But after receiving extra help from experts and Mom, he excels in academics and music. She makes almost every volleyball game and piano recital for her son and daughter. Colleagues say the only time they saw her lose her concentration was when she paused during a meeting and declared, "I've got to have a Little Mermaid costume ready by 5 p.m." --By Chris Taylor/San Francisco