Cenestin has been approved for the treatment of hot flashes, night sweats, and other moderate-to-severe vasomotor symptoms associated with menopause. Cenestin is a slow-release conjugated estrogen product that is synthesized 100% from soy and yam plants. Premarin, the only other slow-release conjugated estrogen product, is derived from pregnant horses.
In clinical trials, the most frequently reported adverse events were headache and insomnia, which occurred with similar frequency in the placebo group. Pregnant women should not use hormone replacement therapy because of possible risk to the fetus.