NutriDex

The Supplement Research Compendium
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Chasteberry (Vitex)

Vitex agnus-castus

Herbal extract used for PMS, breast pain and cycle irregularity.

Moderate evidence 🌙Sleep & Mood

✚ Updated · How we grade evidence

Evidence tier
Moderate
Research weight
Citations
8 verified / 8
Classification
Sleep & Mood
❝
What the evidence says. Graded moderate: multiple placebo-controlled RCTs and meta-analyses show real benefit for PMS and cyclic mastalgia, but trials use different extracts and doses, carry high heterogeneity and risk of bias, and the largest PMS meta-analysis flagged likely publication bias inflating the effect. (Moderate evidence: Several controlled trials; effects real but modest or context-dependent.)

What is Chasteberry (Vitex)?

Chasteberry (Vitex) (Vitex agnus-castus) is a sleep and mood supplement used for ease pms symptoms. NutriDex grades the human evidence as Moderate. Chasteberry is the dried fruit of Vitex agnus-castus, used in Europe mainly for premenstrual syndrome (PMS), cyclic breast pain (mastalgia) and mild menstrual-cycle disturbances. Its diterpenes act on dopamine D2 receptors in the pituitary, lowering prolactin, which may explain effects on breast pain and luteal-phase function. A 2017 meta-analysis of placebo-controlled PMS trials found a large pooled benefit (Hedges g -1.21), but with extreme heterogeneity (I2 91%) and probable publication bias, so the true effect is smaller. For cyclic mastalgia a 2020 meta-analysis (6 trials, 718 women) showed a moderate effect (SMD 0.67) on breast-pain severity. Small early trials also suggest it can normalize shortened luteal phases tied to mildly raised prolactin. It is generally well tolerated; side effects are usually mild. Overall: a plausible, modestly effective option for PMS and breast pain, not a proven treatment for infertility.

Purported Benefits

✓Ease PMS symptoms
✓Reduce cyclic breast pain
✓Lower elevated prolactin
✓Support luteal-phase regularity

Evidence by outcome

The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.

OutcomeEvidenceEffectStudies
Ease PMS symptomsMeta-analysis shows large pooled effect but I2 91% and likely publication bias; RCT (n=170) 52% vs 24% responders. True effect likely smaller. Moderate ↑ benefit · moderate 3
Reduce cyclic breast pain (mastalgia)Meta-analysis of 6 trials (n=718) found a moderate effect (SMD 0.67) on breast-pain severity, with lowered prolactin. Moderate ↑ benefit · moderate 3
Lower elevated prolactinMechanistic D2-agonism reduces prolactin; supported by small luteal-phase trial and mastalgia pooling, not large endpoints. Preliminary ↑ benefit · small 2
Support luteal-phase regularitySingle small RCT (n=52) normalized shortened luteal phases in latent hyperprolactinemia; not a proven fertility treatment. Preliminary ↑ benefit 1

Dosing & Compounds

Typical Dose
Standardized fruit extract ~20–40 mg/day (e.g. Ze 440 or BNO 1095), taken once daily for at least 3 menstrual cycles.
Active Compounds
Diterpenes (clerodadienols)Flavonoids (casticin)Iridoids (agnuside, aucubin)

Safety & Cautions

Generally well tolerated; the most common side effects are mild nausea, headache, GI upset, dizziness, dry mouth, menstrual changes and occasional acne or itchy rash. Because its diterpenes act on dopamine receptors, avoid combining with dopamine agonists or antagonists (e.g. antipsychotics, bromocriptine, metoclopramide), and it may theoretically reduce the reliability of oral contraceptives and interact with hormone therapies. Avoid in pregnancy and breastfeeding, and use caution with hormone-sensitive conditions (breast, uterine or ovarian cancer, endometriosis, fibroids). Discontinue if pregnancy is achieved. Educational only — always check with your doctor or pharmacist before combining Chasteberry (Vitex) with any medicine.

Chasteberry (Vitex) drug interactions

Known or theoretical interactions between Chasteberry (Vitex) and common medications — educational, not exhaustive. Always check with your doctor or pharmacist before combining Chasteberry (Vitex) with any medicine.

Caution
Hormone therapy / tamoxifen
Chasteberry may not be safe with hormone-sensitive conditions such as breast, uterine, or ovarian cancer; use caution.
Chasteberry's effects on prolactin and sex-hormone balance may influence hormone-sensitive tissue and hormone therapy. NCCIH — Chasteberry
Caution
Birth-control pills
Chasteberry may decrease the effectiveness of oral contraceptives; use caution and consider backup contraception.
Dopaminergic, prolactin-lowering activity may alter hormonal signaling and interfere with contraceptive hormones. MSKCC — Chasteberry (Vitex agnus-castus)

Key Studies

Meta-analysis Ooi 2020 ✓ PubMed
Meta-analysis (6 trials, 718 women): moderate effect on cyclic breast-pain severity (SMD 0.67, 95% CI 0.50–0.85) and lowered prolactin.
Meta-analysis Verkaik 2017 ✓ PubMed
Meta-analysis of placebo-controlled PMS RCTs: large pooled effect (Hedges g -1.21) but I2 91% and likely publication bias inflating it.
Systematic review Cerqueira 2017 ✓ PubMed
Systematic review of 8 RCTs: all favored Vitex for PMS/PMDD and it was well tolerated, but definitions, outcomes and extracts varied widely.
Systematic review van Die 2013 ✓ PubMed
Systematic review of Vitex RCTs in reproductive-age women: positive but heterogeneous trials for PMS, mastalgia and cycle disorders.
RCT Schellenberg 2001 ✓ PubMed
RCT (n=170): 52% responded to agnus castus extract vs 24% placebo for core PMS symptoms over 3 cycles (P<0.001).
RCT Halaska 1999 ✓ PubMed
Placebo-controlled RCT: VAS breast-pain fell 33.7mm vs 20.3mm (placebo) after 2 cycles (P=0.006); well tolerated.
RCT Milewicz 1993 ✓ PubMed
RCT (n=52): 20mg/day normalized shortened luteal phases and reduced prolactin in latent hyperprolactinemia over 3 months.
Safety Daniele 2005 ✓ PubMed
Safety review: adverse events mostly mild (nausea, headache, GI upset, acne); no serious drug interactions documented.
8 sources cited · 8 verified Search all studies on PubMed ↗

Common questions about Chasteberry (Vitex)

What is Chasteberry (Vitex) used for?

Chasteberry (Vitex) is most often taken for Ease PMS symptoms, Reduce cyclic breast pain, Lower elevated prolactin, Support luteal-phase regularity. Herbal extract used for PMS, breast pain and cycle irregularity.

Does Chasteberry (Vitex) work — what does the evidence say?

Moderate evidence. Several controlled trials; effects real but modest or context-dependent. Chasteberry is the dried fruit of Vitex agnus-castus, used in Europe mainly for premenstrual syndrome (PMS), cyclic breast pain (mastalgia) and mild menstrual-cycle disturbances. Its diterpenes act on dopamine D2 receptors in the pituitary, lowering prolactin, which may explain effects on breast pain and luteal-phase function. A 2017 meta-analysis of placebo-controlled PMS trials found a large pooled benefit (Hedges g -1.21), but with extreme heterogeneity (I2 91%) and probable publication bias, so the true effect is smaller. For cyclic mastalgia a 2020 meta-analysis (6 trials, 718 women) showed a moderate effect (SMD 0.67) on breast-pain severity. Small early trials also suggest it can normalize shortened luteal phases tied to mildly raised prolactin. It is generally well tolerated; side effects are usually mild. Overall: a plausible, modestly effective option for PMS and breast pain, not a proven treatment for infertility.

What is the typical dose of Chasteberry (Vitex)?

Standardized fruit extract ~20–40 mg/day (e.g. Ze 440 or BNO 1095), taken once daily for at least 3 menstrual cycles.

Is Chasteberry (Vitex) safe? Any cautions or side effects?

Generally well tolerated; the most common side effects are mild nausea, headache, GI upset, dizziness, dry mouth, menstrual changes and occasional acne or itchy rash. Because its diterpenes act on dopamine receptors, avoid combining with dopamine agonists or antagonists (e.g. antipsychotics, bromocriptine, metoclopramide), and it may theoretically reduce the reliability of oral contraceptives and interact with hormone therapies. Avoid in pregnancy and breastfeeding, and use caution with hormone-sensitive conditions (breast, uterine or ovarian cancer, endometriosis, fibroids). Discontinue if pregnancy is achieved.

How many studies support Chasteberry (Vitex)?

NutriDex cites 8 sources for Chasteberry (Vitex), graded "Moderate".

Does Chasteberry (Vitex) interact with any medications?

Yes — known or theoretical interactions include: Hormone therapy / tamoxifen (caution), Birth-control pills (caution). This is educational and not exhaustive; always check with your doctor or pharmacist before combining Chasteberry (Vitex) with any medicine.

Cite this page
APA

Peh, D. (2026). Chasteberry (Vitex) (Vitex agnus-castus): Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 26 Jun 2026, from https://nutridex.info/s/chasteberry

BibTeX
@misc{nutridex_chasteberry,
  author       = {Peh, Daryl},
  title        = {Chasteberry (Vitex) (Vitex agnus-castus): Benefits, Dosage, Side Effects \& Evidence},
  year         = {2026},
  howpublished = {NutriDex --- The Supplement Research Compendium},
  url          = {https://nutridex.info/s/chasteberry},
  note         = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-06-26}
}

For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.

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