Black cohosh oil may cause headaches, upset stomach and liver problems in some patients, according to WebMD. The chance of these side effects is thought to increase as the dose of black cohosh increases. This supplement may interact negatively with birth control pills, hormone-replacement therapies and sedatives.Continue Reading
Black cohosh is an herbal supplement that is frequently used to reduce the symptoms of menopause, according to WebMD. As of 2015, it has increased in popularity since hormone-replacement therapy was found to have negative effects on health. Some studies have shown black cohosh to be effective for treating headaches, hot flashes, mood changes, heart palpitations and night sweats frequently suffered by menopausal women. However, most experts agree that more research needs to be done to determine whether or not black cohosh is indeed effective for these purposes.
The generally recommended dose of black cohosh is 20 to 40 milligrams taken twice per day, according to WebMD. Taking more than 900 milligrams per day is considered an overdose and increases the risk of side effects.
Studies have also investigated the ability of black cohosh to treat arthritis and osteoporosis, according to the University of Maryland Medical Center. Preliminary studies indicate that it may help reduce inflammation caused by osteoarthritis and rheumatoid arthritis. More research is needed to determine whether the plant estrogens contained in black cohosh may also reduce bone loss due to osteoporosis, as of 2015.Learn more about Side Effects