Black cohosh is an herbal supplement derived from a plant in the buttercup family that is native to North America. According to the Office of Dietary Supplements, black cohosh supplements are made from the roots of the plant and sold in tablet or liquid form. Black cohosh contains plant estrogens that act like hormones in your body, and have a wide range of effects. The Food and Drug Administration does not regulate nutritional supplements, nor are they evaluated for safety. Talk to your doctor before using black cohosh to make sure it is safe for you to use.
According to the book, "Your Menopause, Your Menotype," black cohosh is primarily used by women to support reproductive health and hormone balance, particularly during menopause. One of the symptoms of menopause is hot flashes, which can be caused by thyroid imbalances. Black cohosh supplementation can reduce the frequency and intensity of hot flashes in women during menopause. The effect of black cohosh on thyroid function is not well-documented and requires further study.
If you have an over-active thyroid, a condition known as hyperthyroidism, black cohosh supplements should be avoided, according to the book, "Dr. Nieca Goldberg's Complete Guide to Women's Health". If you are taking medications to treat hyperthyroidism, black cohosh can increase your risk of liver function abnormalities. Talk to your doctor if you are taking any medications before using black cohosh.
Black cohosh has been used to reduce the frequency and severity of hot flashes in women with menopause, according to the University of Maryland Medical Center. Hot flashes are typically the result of a hormone imbalance caused by your hypothalamus gland, which regulates body temperature. Black cohosh helps limit the activity of your hypothalamus, which in turn limits its production of corticotropin-releasing hormones which stimulate your adrenal gland to produce adrenaline. By indirectly inhibiting the release of adrenaline, black cohosh can reduce some of the symptoms of menopause.
Your endocrine, or hormonal, system is delicate and can easily be thrown off-balance. Taking black cohosh if you have a hormonal condition, such as menopause or any other condition that affects the normal function of your adrenal glands, can cause a hormonal imbalance. According to the book, "The New Optimum Nutrition Bible," adrenal imbalances can cause irritability, nervousness, cardiovascular changes, insomnia, headaches, muscle tension and other negative effects.