For centuries, chasteberry has been used to treat many hormone-related gynecologic conditions. The current literature supports the use of chasteberry for cyclical breast discomfort and premenstrual syndrome; data on its use for menstrual irregularities and fertility disorders are weak. Its traditional use as a galactagogue (i.e., a substance that enhances breast milk production) is not well supported in the literature and should be discouraged. There are no clinical data to support the use of chasteberry for reducing sexual desire, which has been a traditional application. Chasteberry is well tolerated; reported adverse effects are minor and may include gastrointestinal complaints, dizziness, and dry mouth. No herb-drug interactions have been reported, but caution is advised for its concomitant use with dopamine agonists or antagonists. Optimal standardization and dosing recommendations await clarification in clinical studies.