Chasteberry is the fruit of the chaste tree, native to the Mediterranean region. The fruits have several active compounds, such as flavonoids and essential oils, that may have an effect on hormones, neurotransmitters, and pain and inflammatory pathways in the body. Chasteberry supplements are made from the dried fruit and may be able to help with menstrual disorders, infertility, nursing difficulties, and hormonally induced acne. It can also support a reduction in PMS symptoms.