One of the better-evidenced herbs for classic PMS and breast tenderness — working gently through prolactin and dopamine.
Vitex (chasteberry, Vitex agnus-castus) acts on the pituitary gland in the brain, where it gently lowers prolactin and influences dopamine signalling. Because mildly raised prolactin is linked to PMS, breast tenderness and irregular cycles, easing it can indirectly support progesterone and smoother periods. It is one of the most traditional women's hormone herbs.
For PMS, the evidence is reasonably good. A well-known randomised trial (Schellenberg, 2001, BMJ) found chasteberry significantly improved PMS symptoms — irritability, low mood, breast tenderness — versus placebo, with about half of women responding. It works through brain-pituitary signalling rather than by simply 'topping up' a hormone, so it is best for classic cyclical PMS and cycle irregularity. The honest caveats: it is slow-acting, doesn't suit everyone, and the evidence for fertility or for PCOS is weak — in some women with PCOS it can even make things worse.
Classic PMS (irritability, low mood, bloating before your period), cyclical breast tenderness, or irregular cycles linked to mildly high prolactin.
A common dose is a standardised extract providing around 20–40 mg per day, taken each morning. Capsules with a standardised extract are more reliable than tea, as the active compounds aren't very water-soluble. Use it continuously for 4–6 months to judge the effect.
Take it once daily in the morning, every day of the cycle (not just before your period). Because it works on slow hormonal rhythms, benefits build over several cycles.
Generally mild: occasional headache, nausea, digestive upset or skin reactions. Paradoxically, very high doses may raise prolactin instead of lowering it, so stick to label amounts.
Magnesium and vitamin B6 for PMS support. Use one hormone-acting herb at a time rather than combining several.
Do not use in pregnancy or breastfeeding. It can interfere with hormonal contraceptives and with dopamine-related medications (for Parkinson's or some psychiatric conditions). Avoid if you have a hormone-sensitive condition or a prolactin disorder without medical guidance.
Women with PCOS (it can worsen some cases), anyone on the pill or dopamine medication, and those with a suspected pituitary or prolactin problem.
A standardised Vitex agnus-castus fruit extract with a stated potency, from a reputable third-party-tested brand. Capsules over tea.
Vitex is one of the better-evidenced herbs for classic PMS and cyclical breast tenderness, working gently through prolactin and dopamine. Take a standardised 20–40 mg each morning for several months — but avoid it in pregnancy, on the pill, or with PCOS unless advised.
Schellenberg 2001, BMJ (chasteberry for PMS RCT); NCCIH chasteberry monograph; reviews of Vitex agnus-castus and prolactin.
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Based on guidance from the NHS, NICE, Cleveland Clinic and peer-reviewed research.
General information, not a substitute for personal medical advice — always consult your doctor or a qualified health professional before making health decisions. If you are pregnant, breastfeeding, trying to conceive, under 18, or taking medication, speak to your doctor before starting any supplement.