Natural Factors Vitex - 80 mg - Helps balance female hormones to reduce the symptoms of PMS. This formula provides support for the female reproductive system, while effectively relieving the symptoms of PMS, including breast tenderness, bloating, fatigue, and irritability. Vitex agnus-castus (Chastetree berry) has been used for thousands of years to treat female hormonal disruptions, ranging from premenstrual syndrome (PMS) to menopause. Vitex has an effect on the pituitary gland, which is located in the brain and produces hormones that stimulate the production of sex hormones in other areas of the body.