Vitex / Chasteberry

Women's hormonesPMSProgesterone

The classic women's hormone herb. Raises progesterone (indirectly), normalises menstrual cycles, and is the most evidence-backed natural intervention for PMS and PMDD.

EvidenceStrong

Strong evidence for PMS symptom reduction (especially breast tenderness, mood, irritability) — multiple RCTs and meta-analyses. Strong for PMDD adjunct, cyclic mastalgia, and mild luteal phase defect. Moderate for normalising irregular cycles. Effects: 8–12 weeks (3 cycles).

Vitex agnus-castus (chasteberry, monk's pepper) is a Mediterranean shrub used for women's hormonal complaints since antiquity. Its mechanism is unusual: it doesn't contain hormones, it acts on the pituitary's dopamine D2 receptors to reduce prolactin secretion. Lower prolactin → better luteal-phase function → more progesterone production → less estrogen dominance → fewer PMS symptoms. The German Commission E and most European pharmacopeias accept it for PMS, irregular cycles, and breast tenderness. The most evidence-backed herbal supplement for women's cyclical symptoms.

Form: Standardised vitex extract (BNO-1095, Ze 440 — the forms used in most German trials). Look for ≥0.5% agnusides on the label.
Dose: 20–40 mg/day standardised extract. Most trials use 20 mg of BNO-1095.
Timing: AM. Once daily.
Schedule: Daily, ongoing for cycle regulation. Allow 3 full menstrual cycles before judging effects.
Side effects: Generally well-tolerated. GI upset, headache, acne (transient), menstrual changes (the point — but can be unwanted at first). Skin reactions rare.
Interactions: Hormonal contraceptives — vitex may reduce efficacy by altering hormone signalling. HRT — interaction unclear; coordinate with provider. Dopamine agonists (bromocriptine, cabergoline) — additive at the dopamine receptor. Antipsychotics (dopamine antagonists) — opposing.
Contraindications: Pregnancy / breastfeeding (theoretical hormonal effects). On hormonal contraception (use additional birth control or avoid). Hormone-sensitive cancers. Pituitary disorders. Active IVF cycle.
Lab markers: Cycle tracking (length, symptoms). Progesterone (day 21 of cycle). Prolactin if elevated baseline.
Food sources: Not present in food.

Pairs with

Magnesium, vitamin B6 (P5P) (PMS stack). DIM / Calcium D-glucarate (estrogen metabolism support).

within Herbs & botanicals