Vitex Agnus-Castus for the Treatment of Cyclic Mastalgia: A Systematic Review and Meta-Analysis

Cyclic mastalgia (CM) is premenstrual bilateral and diffuse breast pain that presents cyclically and affects women in their reproductive years. It may associate with latent hyperprolactinemia due to the insufficient inhibitory effect of dopamine on the pituitary gland. Vitex agnus-castus (VAC) is known for its dopaminergic activity and its possible actions on CM and latent hyperprolactinemia. However, the treatment effect of VAC on CM remains unclear. To perform a systematic review and meta-analysis of clinical trials that report on the efficacy of VAC treatment in CM patients, literature search was performed in major research databases. This review includes 25 studies (17 randomized control trials plus eight nonrandomized trials). VAC was effective in relieving breast pain intensity and lowering the increased serum prolactin level in reproductive age CM patients (18-45 years) with or without premenstrual syndromes. Typical dosage was 20-40 mg/day with a treatment duration of 3 months. A conservative meta-analysis included only six studies (n = 718, VAC = 356, placebo = 362) and revealed a moderate effect size (SMD: 0.67, 95% CI: 0.5-0.85) favoring VAC over a placebo. Seven trials demonstrated VAC to be a noninferior alternative to pharmaceutical therapies for CM, including dopamine agonists, nonsteroidal anti-inflammatory drugs, serotonin reuptake inhibitors, and hormonal contraceptives. VAC was safe and associated with only mild and reversible adverse events. However, the risk of bias in most studies was unclear due to insufficient information. VAC is a safe and effective treatment option for CM. More high-quality clinical trials are needed to strengthen the evidence base.