Because doctors have no solutions, women have tried less-proven treatments for their low sexual desire, such as diets and herbs. None of Foust's clients has had success with them. She said some women who aren't functioning well sexually would be "open to anything."
"I've had women complain, 'Why isn't there a female Viagra?' " Foust said.
Sex drive: It's complicated
Sex drive is more complicated for women than for men, Foust said. There are a lot of factors that could explain a woman's low desire -- and not all of them are medical, she said. Lifestyle and relationship issues may come into play.
Having a first child can be a problematic factor for some women; the adjustment and figuring out how to restructure their sex life can throw off desire. Foust has spoken to some new mothers who feel they are constantly being asked for something from their body, as if they are "touched out," but find their lack of desire troubling.
Some couples maintain satisfying sex lives over many years -- but some, over time, go on autopilot and have less and less sex.
"You have to continue to feed your sexual relationship, and feed your relationship in general," Foust said. "A lot of it depends on how much importance and energy you put toward your sex life."
Sometimes stress is the issue, too, she said.
Foust offers cognitive-behavioral, focused exercises to help women who are distressed about their low sexual desire.
Low sexual desire in women isn't necessarily a problem in menopause or later. Foust works with many women complaining of low sex drive who are in their 30s and 40s. The average age of participants in the flibanserin trials was 36, Whitehead said.
The new drug application the company will submit will be specifically for premenopausal women.