Black cohosh is an herb that has been repeatedly suggested to help reduce hot flashes in menopausal women. Researchers have finally identified the molecular mechanisms underlying this effect, and found that elements of the herb could bind to the human 'mu' opiate receptor", which affects neurotransmitters important for temperature regulation.

Although the exact mechanism of the hot flash is unclear, estrogen withdrawal during menopause clearly plays an important role, Wang said. It is assumed that declining estrogen concentrations may change the levels of brain chemicals called neurotransmitters.

As a result, the thermoregulatory center located in the hypothalamus functions irregularly, which leads to inappropriate peripheral vasodilatation that causes hot flashes.

"The hypothalamic thermostat setting can be controlled directly or indirectly by the opiate system," Wang said.

The black cohosh extract used in this study is currently under a Phase II clinical trial. For more on black cohosh and menopause, refer to the Q&A compiled by the office of Dietary Supplements.