Vitex, also known as chasteberry is an ancient herbal remedy used primarily to address health concerns important to women, specifically those dealing with the reproductive system. According to the Memorial Sloan-Kettering Cancer Center, a limited number of clinical trials--those that used human participants--indicate that vitex (chasteberry) is helpful for symptoms of PMS and painful menstruation in healthy women between the ages of 20 and 40. However, even natural remedies like vitex can cause side effects and may interfere with some medications.

Adverse Effects

A December 2005 review published in "Drug Safety" by the University of Rome La Sapienza assessed potential adverse side effects associated with using vitex. The review concluded that those most frequently reported were gastrointestinal disturbance, nausea, headache, acne, itching, rash and menstrual disorders.

Interaction with Medications

The "Drug Safety" study indicated that no drug interactions were reported with use of vitex. However, theoretically, it may have some effect on how the brain releases dopamine. The National Center for Complementary and Alternative Medicine cautions people to avoid chasteberry if you take dopamine-related drugs. These may include selegiline, amantadine and levodopa.

Hormonal Effects

The Memorial Sloan-Kettering Cancer Center states that vitex contains sex hormones (progesterone), so it may affect hormone levels. Patients should avoid taking vitex if they are pregnant or have a hormone-related health condition, such as breast cancer, cautions NCCAM. Also, patients shouldn't use vitex if they take oral contraceptives, as it may interfere with how well this medication works. The cancer center further notes that vitex has not been established as a safe or effective alternative to hormone replacement therapy (HRT) used to treat symptoms of menopause.

Other Cautions

Vitex, or chasteberry, is not a medication. The U.S. Food & Drug Administration classifies it as a dietary supplement, so the product that patients select should not make claims to treat or cure any medical condition, nor is the quality of the product guaranteed. If people intend to take this supplement to address their health concerns, they should talk to a doctor first.