Up to 85% of women experience hot flashes and night sweats during the menopause transition, for a median duration of four years. In 2008, according to U.S. census data, more than 11.5 million women in the U.S. were in the 45-to-49 age range to enter menopause. In addition, most women receiving systemic therapy for breast cancer suffer hot flashes, often with more severe or prolonged symptoms than women experiencing menopause. These symptoms can disrupt sleep and interfere with quality of life. An estimated two million women undergo menopause every year in the U.S., with a total population of 50 million postmenopausal women.

Historically, hormone replacement therapy (HRT) with estrogen and/or progesterone has been the standard of care for relieving menopausal symptoms such as hot flashes. Data from the Women's Health Initiative (WHI), however, identified increased risks for malignancy and cardiovascular disease associated with estrogen therapy. Due to concerns about the potential long-term risks and contraindications associated with HRT, there is a significant need for new therapeutic options to treat menopausal symptoms.