What Is Chasteberry?

Written by Marijke Vroomen Durning, RN, Kelli Miller
Medically Reviewed by Jabeen Begum, MD on June 10, 2025
7 min read

Chasteberry is a fruit growing on trees or shrubs of riverbanks in parts of Asia. But it's also found in the Mediterranean and the southeastern U.S. 

The scientific name for chasteberry is Vitrex agnus-castus. The flowering plant is a member of the mint family. The word chaste means pure. Chasteberry got its name from the belief that it could lower sexual desire. It's also called monk's pepper.

People have been using chasteberry for over 2,500 years. Some believe the berry may help balance your hormones. In the Middle Ages, monks used chasteberry to lower sexual desire.

In traditional medicine, chasteberry treated psychological problems. People also used it for hormone-related skin conditions and menstrual cycle issues.

It's unclear how chasteberry works. But the plant may lower inflammation and balance hormones.

Chasteberry contains several helpful compounds such as:

  • Flavonoids like casticin may act as an opioid to lower pain. They may also help your brain, heart health, and fight cancer.
  • Apigenin, another flavonoid, may act like a phytoestrogen. This plant compound may bind estrogen receptors and raise progesterone.
  • Agnuside, an iridoid glycoside, might help fight viruses and repair damaged cells.
  • Clerodadienols may act like dopamine (dopaminergic). These compounds may lower prolactin levels to help your PMS symptoms.
  • Diterpenes may help raise your dopamine levels. Dopamine is sometimes called the "feel-good" hormone.
  • Linoleic acid may help turn on certain hormones and act like progesterone.

A few small but higher quality studies suggest chasteberry may have a few benefits. Chasteberry may help conditions that cause your sex hormones, progesterone and estrogen, to rise and fall.

"It's often used as a dietary supplement, particularly around premenstrual syndrome (PMS), breast pain, tenderness, infertility, and menopause," says Vanessa King, RDN, CNSC, NBC-HWC, a dietitian, nutritionist, and spokesperson for the Academy of Nutrition and Dietetics at Queen's Medical Center.

The supplement contains certain chemicals such as flavonoids and phytoestrogens. These compounds may lower inflammation and balance hormones.

Chasteberry for PMS symptoms

The supplement may help lower breast pain, headache, and mood swings. But there aren't many high quality studies to support this. 

One study showed chasteberry helped with breast fullness, not pain. And other trials found chasteberry didn't help. Some evidence suggests the plant might help to moderately improve breast tenderness. 

"Two studies of less than 200 people showed a small improvement in irritability," King says. 

Chasteberry for menopause

The supplement may help lower the number of hot flashes and night sweats. Chasteberry may act like a phytoestrogen to mimic estrogen. But it's still unclear if the herb really helps.

Remember, the studies are limited. But some women claim the plant helps lessen:

  • Hot flashes
  • Night sweats
  • Irritability

In Germany, chasteberry is approved to help irregular menstrual cycles, breast soreness, and other PMS symptoms.

Can chasteberry help PMDD?

Without strong study results, it's unclear if chasteberry helps premenstrual dysphoric disorder (PMDD). Some small studies show chasteberry may help. 

Because the herb may mimic dopamine, it may lower prolactin levels. This can help lower your PMS and PMDD symptoms. But another small study showed that fluoxetine better treated PMDD emotional symptoms.

Can chasteberry support fertility and reproductive health?

In Germany, some doctors prescribe chasteberry for luteal phase problems. Luteal phase problems can cause infertility (trouble getting pregnant). 

This means the time is too short between your ovary releasing the egg and your period starting. During this stage, your progesterone levels get higher. That's why chasteberry may help. But endometriosis, polycystic ovary syndrome, or thyroid disorder can also cause a shorter luteal phase.

Chasteberry for acne and skin health

Some companies claim chasteberry helps clear up acne and improve skin health. There aren't any scientific studies to support these claims. In fact, side effects of chasteberry include acne-like rashes.

Since chasteberry is a supplement, it isn't regulated like a medication. That means there isn't a suggested daily amount.

Many studies use 4 milligrams (mg), each day, of a 6% agnuside extract. Agnuside is a compound called iridoid glycoside. But a few studies also use doses up to 20 mg of the extract. And supplement labels can range from 300 mg to 500 mg per serving or dose. 

Labels on fluid extract may suggest 40 drops each day and on tinctures may suggest 35-40 drops up to three times a day. Talk to your doctor about the best dose for you and your health.

Can you get chasteberry naturally from foods?

You can't find chasteberry naturally in foods, it's a supplement. Chasteberry is extracted from the plant's leaves, stems, flowers, and seeds.

Chasteberry is usually safe in the short term. But the herb may not be safe for everyone. It's important to talk with your health care provider. They'll help you weigh the benefits and risks of chasteberry.

"I think it's important to note that some of the studies people are talking about are actually based on animals," says King. "So when you're seeing benefits to hormones like estrogen and progesterone levels, we can't translate that to human safety."

Just like any medicine, the herb can come with some side effects.

What are the side effects of taking chasteberry?

Most people seem to tolerate chasteberry. With chasteberry side effects, you may get:

  • Acne
  • Headache
  • Menstrual bleeding
  • Rash (pruritus or erythematous rash)
  • Stomach upset and nausea
  • Weight gain
  • Dizziness
  • Dry mouth
  • Fatigue

There has been one report of seizures at night. The cause is unclear, but chasteberry was taken with black cohosh and evening primrose oil.

What are the risks of taking chasteberry?

The FDA doesn't regulate dietary supplements like medications. Supplements are treated like foods. Companies don't have to test supplements to show they work.

Some studies showed chasteberry supplements contained other plants. 

Instead of chasteberry (Vitrex agnus-castus),the supplements may have:

  • Vitex trifolia
  • Vitex rotundifolia
  • Vitex negundo

The supplements may also have altered levels of agnuside and casticin. This can impact how well your chasteberry works.

Chasteberry drug interactions

Chasteberry can affect your medicine levels. The herb may change your dopamine levels, too. 

Avoid chasteberry if you take:

  • Medicines to stop psychosis (antipsychotics), like phenothiazines or dopamine D2 antagonists
  • Medication to help with Parkinson's (antiparkinsonian compounds), such as bromocriptine (Parlodel)
  • Oral contraceptives or hormone therapy
  • Medication that uses the cytochrome enzymes called CYP2C19 or CYP3A4

Who should avoid chasteberry?

It's unclear, but chasteberry may alter your hormone levels. Your hormones can play a key role in menstruation, reproduction, and some cancers. 

Avoid chasteberry if you:

  • Have a hormone-sensitive condition like breast, uterine, or ovarian cancer
  • Are pregnant or breastfeeding (chestfeeding)
  • Take birth control pills or hormone replacement
  • Take antipsychotics, antiparkinsonian medicines, or medications changed by CYP2C19 or CYP3A4 cytochrome enzymes

Always tell your doctor about any supplements you take. That way, your doctor can check for any side effects. They can tell you if your medications react with chasteberry, too.

Chasteberry has been used for thousands of years but it's still unclear how the herb works. Some people use chasteberry to manage breast pain, menopause, and other PMS symptoms. Always talk to your health care provider to make sure it's safe and find out about any medication interactions.

What is chasteberry in Greek mythology?

In ancient Greece, chasteberry was used in a religious farming festival of Thesmophoria. The plant honored the Greek goddess Demeter and her daughter, Persephone. Chasteberry was also used to honor the Greek goddess Hera. 

Each goddess tied to the cycle of life:

  • Demeter was the goddess of fertility.
  • Persephone was the goddess of spring.
  • Hera was the goddess of marriage.

What does chasteberry do to your period?

It's unclear, but some small studies show chasteberry may act like dopamine to lower prolactin. Higher prolactin amounts before your period might cause you:

  • Breast pain (mastalgia)
  • Some symptoms of PMS

Chasteberry may also help correct luteal phase problems. In Germany, some doctors use chasteberry to help with infertility (trouble getting pregnant). But other studies show no effect using chasteberry, too.

Does chasteberry raise estrogen levels?

It isn't clear, but some research suggests chasteberry acts like a phytoestrogen. Phytoestrogens act similar to estrogen without raising your estrogen levels. 

In fact, chasteberry may help PMS and menopause symptoms. But it is still unclear and needs more high-quality studies.

Is chasteberry an anti-inflammatory herb?

Yes, chasteberry contains anti-inflammatory compounds called iridoid glycosides. Agnuside is the active anti-inflammatory compound in chasteberry. And one study showed chasteberry may lower an inflammatory marker called C-reactive protein (CRP).

Does chasteberry help with anxiety?

It's not clear if chasteberry can help with anxiety. But chasteberry contains compounds such as diterpenes. These chemicals can impact your dopamine levels. Chasteberry extracts may bind to and turn on your brain's dopamine (D2) receptors. 

Activating your dopamine may help some psychological hormone-related symptoms. But it can also interrupt the medicines to stop psychosis (antipsychotics) and dopamine D2 antagonists.

Does chasteberry lower cortisol?

It's unclear how chasteberry impacts cortisol. There aren't many studies about cortisol and chasteberry in humans. Cortisol is made by your adrenal glands. Normally, stress causes higher cortisol levels. But in certain medical conditions like premenstrual dysphoric disorder (PMDD), cortisol stays low.

Another hormone, adrenocorticotropic hormone (ACTH) causes your adrenal glands to raise cortisol. But in horses, the guidelines list chasteberry as having no effect on ACTH. This means the supplement likely has no effect on cortisol. But more studies in humans are needed to be sure.