Chasteberry (Vitex agnus-castus)

Commonly used for
Hormone Balance
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What is it? / Overview
Chasteberry is thought to act on dopamine receptors in the pituitary gland, which may help modulate prolactin levels; it's one of the better-studied herbal options for PMS symptom relief and cycle regularity, though the exact mechanism isn't fully settled.
How is it used? / Administration
Form: Standardized extract (typically 4:1 or 6:1, standardized to agnuside/casticin)
Typical dose studied: 20–40 mg/day (extract)
Timing: Morning, consistently every day
Not appropriate during pregnancy or while trying to conceive without physician guidance. Can theoretically interact with hormonal medications given its effect on prolactin/dopamine pathways.
How well does it work? / Evidence
~ Moderate evidence
Who should avoid it?
Avoid with: PCOS (Polycystic Ovary Syndrome)
Interacts with: Hormonal birth control; Antipsychotic medications
Already taking it? Effects build over 2–3 menstrual cycles. Discontinue and consult a doctor if using hormonal medications or if periods stop unexpectedly.
Research & references
van Die MD et al. Vitex agnus-castus systematic review. Schellenberg R. Vitex for PMS — randomized controlled trial.
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