Vitex (Chasteberry): Uses, Benefits, Dosage & Safety

Last updated: June 2026 · Reviewed by the FactoWiki Editorial Team for clarity and source accuracy

What is Vitex (Chasteberry)?

Vitex (Vitex agnus-castus), commonly called chasteberry or chaste tree, is the fruit of a Mediterranean shrub used in European herbal medicine for menstrual and premenstrual complaints. Standardized extracts (such as Ze 440 and BNO 1095) are sold for PMS, breast tenderness and cycle irregularities. It is one of the more studied women's-health herbs — though, as so often with botanicals, the quality of the trials is the sticking point.

What Vitex (Chasteberry) is commonly used for

In supplements, Vitex is used mainly for premenstrual syndrome (PMS), cyclical breast tenderness (mastalgia) and menstrual-cycle irregularities, and is popular in fertility circles. It is sold as support for premenstrual symptoms, and is one of the few herbs that mainstream reviews treat as genuinely worth studying further.

How Vitex (Chasteberry) works

Vitex appears to act on the pituitary gland, gently lowering the hormone prolactin and shifting the balance of reproductive hormones across the cycle — which is the rationale for its use in PMS and cyclical breast pain, conditions tied to hormonal fluctuation. Because it works through hormones, both its effects and its cautions flow from that same mechanism.

What the evidence says

Here's an honest snapshot of what published research suggests about Vitex (Chasteberry) — including where the evidence is limited.

• A systematic review and meta-analysis of 17 randomised trials found a large pooled benefit of Vitex agnus-castus for premenstrual symptoms, but cautioned that high risk of bias, high heterogeneity and signs of publication bias likely overstate the true effect. (PubMed)
• General background on chasteberry is summarised by reputable health references; health authorities generally regard the evidence for PMS as promising but not conclusive. (MedlinePlus)

Typical dosage used in studies

Standardized extracts are usually taken once daily over several menstrual cycles, with the specific amount depending on the preparation. Benefits, where they occur, tend to build over two to three cycles rather than immediately. This is general information from research, not a recommendation.

Side effects and safety

Vitex is generally well tolerated. Mild side effects include nausea, headache, digestive upset and occasional skin reactions or changes in menstrual bleeding. Because it affects reproductive hormones, it is not recommended during pregnancy or breastfeeding.

Medication interactions and who should avoid Vitex (Chasteberry)

Sources & further reading

The evidence summary above is drawn from these sources. For general, authoritative background you can also consult:

• PubMed-indexed study (PMID 28237870)
• MedlinePlus
• NIH Office of Dietary Supplements
• NIH National Center for Complementary and Integrative Health

Frequently asked questions

Does vitex help PMS?

A meta-analysis found a large pooled benefit, but the underlying trials had a high risk of bias, so health authorities describe the evidence as promising rather than conclusive. Real-world effects are likely smaller than the headline figure.

How long does vitex take to work?

Because it acts on the menstrual cycle, benefits typically build over two to three cycles rather than right away. It is not a fast-acting remedy.

Can I take vitex with the pill?

Be cautious. Vitex affects hormones and may interfere with hormonal contraceptives and HRT, so it is worth discussing with a clinician before combining them.

Is vitex safe in pregnancy?

No. Because it affects reproductive hormones, vitex is not recommended during pregnancy or breastfeeding.

Does vitex help fertility?

It is traditionally used for cycle regulation and is popular for fertility, but solid evidence that it improves fertility is limited.