Vitex (Chasteberry)

Vitex agnus-castus (chasteberry) is an herbal extract used traditionally for menstrual symptoms. Some trials suggest it may help with PMS symptoms, and it may lower prolactin, but evidence for improving cycle regularity or fertility is limited and not conclusive. Because it can affect hormones, it is not suitable for everyone.

People with PMS or cycle concerns who want to discuss it with a clinician — it can interfere with hormonal treatments. Whether it suits you depends on your health, medicines and test results — ask a clinician.

Studies have used roughly 20–40 mg of dried-extract daily, or the labelled dose of a standardized product. Products vary. This is not a recommendation. Doses vary by product and person; this is not personal medical advice.

Studies usually lasted about 3 cycles or longer.

Mild stomach upset, headache, acne, or menstrual changes.

Do not use with hormonal birth control or fertility medicines unless your clinician agrees. Ask your doctor first if you have PCOS, a hormone-sensitive condition, or are trying to conceive. Stop if you may be pregnant.

Evidence level (our editorial summary, not a formal grading): Limited.

Pregnancy & breastfeeding: Not recommended in pregnancy or breastfeeding (it may affect prolactin and milk supply). Stop if you may be pregnant.

Medication interactions: May interact with hormonal contraceptives, hormone therapy, fertility medicines and dopamine-related medicines.

Talk to a healthcare professional before use if you are pregnant, breastfeeding, planning pregnancy, have a medical condition, take any medicine, or are scheduled for surgery. Dietary supplements are not approved by the FDA for safety or effectiveness before they are sold, and quality varies between products.

Reliable sources to check: NIH Office of Dietary Supplements fact sheets · NCCIH Herbs at a Glance · MedlinePlus Herbs & Supplements · FDA — Dietary Supplements