Another biopharmaceutical company, DepoMed , is also aiming to get FDA approval for a gabapentin drug, intended to treat menopausal hot flashes and postherpetic neuralgia.

FORBES: FDA Concerns Shake XenoPort, DepoMed

But a large, NIH-sponsored, carefully controlled study published in the Annals of Internal Medicine Monday reports that, unlike HRT, the supplement doesn't work to help hot flashes or other menopausal symptoms.

NPR: Menopause Study: Herbal Remedies Don't Help

"We use menopausal hormone therapy for women with moderate to severe hot flashes interfering with their lives, " Crandall said.

CNN: Government panel: Hormone therapy 'not recommended'

The latest in a series of disappointing studies finds that soy supplements, an increasingly popular substitute for hormone therapy, do not stave off hot flashes, night sweats, and other uncomfortable menopausal symptoms.

CNN: Soy no help for bone loss, hot flashes