Chasteberry (Vitex agnus-castus): Uses, Evidence and Safety
Chasteberry (Vitex agnus-castus) fruit extract for PMS and breast pain: what NIH, EU regulators and a meta-analysis found, with cautions on hormone medicines and pregnancy.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
What is Chasteberry good for?
What the body uses it for, and how strong the evidence is. A normal job in the body is not proof that extra supplements add benefit; each card says which.
PMS symptoms
Clinically supportedSome studies suggest fruit extract may ease premenstrual symptoms such as breast tenderness, irritability and mood change, but the studies are of mixed quality.
Supplements: Evidence is limited: NIH calls the studies low to moderate quality, and a 2017 meta-analysis found a large pooled effect but high bias, very high heterogeneity and likely publication bias. The EU recognises one dry extract for PMS (one placebo-controlled study in 178 women); other preparations are accepted on traditional use only.
Menstrual-related breast pain
Preliminary or mixedA few small trials have looked at breast pain linked to the menstrual cycle; breast tenderness is also counted within PMS studies.
Supplements: Few trials; NIH gives no separate conclusion beyond PMS studies.
Possible effect on prolactin (laboratory)
Lab or animal research onlyLaboratory studies suggest the fruit may act on the brain's hypothalamus and pituitary gland and lower prolactin, a hormone thought to play a part in PMS.
Supplements: Laboratory findings; not shown to explain benefit in people.
Heavy bleeding with an IUD
Not enough evidenceOne study suggested it might reduce heavy bleeding in women with an intrauterine device, but the evidence is low quality.
Supplements: Not enough evidence to say it works.
Infertility and sexual dysfunction
Not enough evidenceChasteberry is widely sold for fertility, but there is not enough reliable evidence to know whether it helps.
Supplements: No reliable evidence of benefit; NIH also says use in pregnancy may be unsafe.
Menopause symptoms
Not enough evidenceA preliminary study hinted at benefit, but a study combining it with St. John's wort found no relief of menopausal symptoms.
Supplements: Evidence does not support use for menopause symptoms.
Connected topics
Open a group to see how each topic connects and how strong the evidence is.
Health goals (1)
- Women’s WellnessPreliminary or mixed
Used mainly for premenstrual symptoms; studies are limited and mixed in quality, so evidence is promising but not firm.
Body systems (2)
- Reproductive HealthPreliminary or mixed
Studied for cycle-related symptoms (PMS); evidence is limited, and it may be unsafe in pregnancy.
- Reproductive SystemPreliminary or mixed
Studied for cycle-related symptoms (PMS, breast tenderness); evidence is limited.
Root causes (1)
- Medication Side EffectsDocumented risk
Lab studies suggest it may weaken hormone medicines and affect antipsychotic and Parkinson's medicines; clinical meaning is unknown, so check with a prescriber.
Conditions & symptoms (2)
- Premenstrual SyndromeClinically supported
One dry fruit extract is recognised in the EU for PMS; wider evidence is limited and mixed in quality.
- Breast Pain FemalePreliminary or mixed
A few small trials on cycle-related breast pain; limited evidence.
Documented risks and interactions (5)
- Hormone-sensitive conditions caution. Chasteberry may not be safe for women with hormone-sensitive conditions such as breast, uterine or ovarian cancer; ask a clinician first.
- Pregnancy and breastfeeding. Use in pregnancy or while breastfeeding may be unsafe, so sources advise avoiding it.
- Hormone medicines and contraceptives. Laboratory studies suggest chasteberry may reduce the effect of birth control pills and other hormone medicines. The clinical meaning is not known.
- Antipsychotic and Parkinson's disease medicines. Laboratory studies suggest it may change how antipsychotic and Parkinson's disease medicines work. The clinical meaning is not known.
- Common side effects and allergy. Usually mild: nausea, stomach pain, diarrhoea, headache, itching. The EU summary also lists rash, acne, dizziness, menstrual changes and rare severe allergic reactions.
Safety first: hormones, dopamine medicines and pregnancy
Chasteberry may not be safe for women with hormone-sensitive conditions such as breast, uterine or ovarian cancer, and its use in pregnancy or breastfeeding may be unsafe, according to NIH. [1] Memorial Sloan Kettering also lists lab-based cautions with antipsychotic medicines, Parkinson's disease medicines, birth control pills and other hormonal medicines. The clinical meaning of those lab findings is not yet known. [2] Ask the prescriber or pharmacist first. See medicine interactions and supplements and hormone medicines.What it is
Chasteberry, also called chaste tree or vitex, is native to the Mediterranean and Central Asia. NIH says extracts may be made from the leaves, stems, flowers and seeds. [1] The accepted name is Vitex agnus-castus L., in the mint family (Lamiaceae). [3] The EU regulator's conclusions cover the fruit, either dried and powdered or as a dry or liquid extract. [4] A result for the fruit extract does not transfer to other plant parts.Traditional use
NIH says the name may reflect a belief that the plant promoted chastity, and that in the Middle Ages monks reportedly used it to lower sexual desire. It was also traditionally used for psychological illnesses, gynecological disorders and hormone-related skin conditions. [1] This is traditional use, not evidence that it works.What research shows
| Use | What the source found | Strength of evidence | Population and form studied |
|---|---|---|---|
| PMS symptoms (including breast tenderness) | NIH: several low-to-moderate quality studies; higher-quality evidence is needed. [1] | Promising but limited | Women with PMS; fruit extracts |
| PMS, meta-analysis | A 2017 review of 17 randomized trials found a large pooled effect, but high risk of bias, very high heterogeneity and likely publication bias prevent a definite conclusion. [5] | Mixed | Women with PMS or PMDD |
| PMS, EU regulator | One dry extract is recognized for PMS over 3 months based on a study in 178 women compared with placebo. Other preparations are accepted on traditional use only. [4] | Regulatory "well-established" (one extract) and "traditional use" | Adult women |
| Heavy bleeding with an IUD | One study suggested benefit; evidence is low quality. [1] | Insufficient evidence | Women with an intrauterine device |
| Infertility and sexual dysfunction | Not enough reliable evidence. [1] | Insufficient evidence | Not applicable |
| Menopause symptoms | A preliminary study hinted at benefit. [1] Memorial Sloan Kettering notes that one study with St. John's wort found no help. [2] | Insufficient evidence | Menopausal women |
The EU summary says laboratory studies suggest the fruit may act on the hypothalamus and pituitary gland and reduce production of prolactin, a hormone thought to play a role in PMS. [4] For other options see herbs for menstrual cramps and PMS and PMS and PMDD.
Forms
The EU summary describes solid or liquid forms taken by mouth, made from dried powder or extracts; combination products with other herbs are not covered. [4] See forms and preparations. A clinician or pharmacist decides what is right for a person; the EU committee says medicines are for adult women only and to see a doctor if symptoms worsen or continue. [4]Safety details
- Common effects: nausea, stomach pain, diarrhea, headache or itching; NIH says it was used safely in studies for up to 3 months. [1]
- EU-listed side effects include severe allergic reactions with face swelling and breathing or swallowing difficulty, rash and acne, dizziness and menstrual disorders. [4]
- Hormone medicines and IVF: Memorial Sloan Kettering says lab studies suggest chasteberry may reduce the effects of hormone therapies and contraceptives. [2] If you are planning pregnancy or in fertility treatment, see trying to conceive; NIH notes the evidence for infertility is thin and use in pregnancy may be unsafe. [1]
- Other medicines: lab work suggests possible effects on liver enzymes (CYP2C19 and CYP3A4) that clear some drugs. [2]
- Children, older adults, liver and kidney disease, surgery: not described in the sources we read.
- Quality: see quality testing.
Frequently asked questions
Does chasteberry help PMS?
Some studies suggest it may reduce symptoms, but NIH says higher-quality evidence is needed. [1]
Is chasteberry the same as vitex?
Yes. NIH lists vitex as a common name for Vitex agnus-castus. [1]
Can I take chasteberry with birth control?
Ask your prescriber or pharmacist. Lab studies suggest it may interfere with contraceptives. [2]
Is chasteberry safe in pregnancy?
NIH says use in pregnancy or breastfeeding may be unsafe. [1]
Does it affect hormones?
The EU summary says lab studies suggest an effect on prolactin through the brain. [4]
References
- NCCIH, NIH. Chasteberry. Read 2026-10-23.
- Memorial Sloan Kettering Cancer Center. Chasteberry: Purported Benefits, Side Effects and More. Read 2026-10-23.
- GBIF Backbone Taxonomy. Vitex agnus-castus L.. Read 2026-10-23.
- European Medicines Agency, HMPC. Agnus castus fruit: summary for the public, EMA/266692/2018. Read 2026-10-23.
- Verkaik S, et al. The treatment of premenstrual syndrome with preparations of Vitex agnus castus: a systematic review and meta-analysis. Am J Obstet Gynecol. 2017;217:150-166. Read 2026-10-23.