For centuries, chasteberry was believed to promote chastity by reducing sexual desire, hence its name. It has also been historically used to increase lactation during and after pregnancy. However, these traditional applications have not been clinically investigated. Read on to learn how this supplement works, its benefits, and potential risks of its use.

What is Chasteberry?

Chasteberry, also known as Vitex agnus-castus, is the fruit of the chaste tree, which is native to western Asia and southwestern Europe [1].

This fruit is used as a dietary supplement for conditions such as menopause, infertility, menstrual problems, and a number of other conditions. It is available as a capsule, liquid extract, tablet, and essential oil [1].


The chasteberry is composed of [2, 1]:

  • Flavonoids (casticin, kaempferol, orientin, quercetagetin, and isovitexin): These are plant pigments that are naturally found in a variety of nuts, fruits, and vegetables. These chemicals have anti-inflammatory, anti-cancer, and anti-viral properties [3].
  • Essential oils (limonene, cineol, pinene, and sabinene): These are the naturally occurring chemicals that give the chasteberry (and other fruits) its odor and flavor. Blends of essential oils are frequently used in aromatherapy for their effects in decreasing heart rate and blood pressure [4].
  • Anti-inflammatory compounds (iridoid glycoside): These compounds have similar effectiveness in treating inflammation as NSAIDs with far fewer side effects [5].

Mechanism of Action

Chasteberry increases dopamine activity in the brain. This results in a reduction of prolactin release in the body [1].

When too much prolactin is circulating in the body, it can cause disturbances in the menstrual cycle as well as a deficiency in levels of estrogen (in women) and testosterone (in men) [1].

However, these hormonal changes appear to be dose-dependent. Low doses (200 mg) of chasteberry can increase levels of prolactin and progesterone (likely by the inhibition of other hormones (FSH and LH)). At high doses (500 mg) of chasteberry, levels of prolactin are decreased (with LH and FSH levels unaffected) [1].

Additionally, chasteberry may stimulate opioid receptors. Opioid drugs are medically used as painkillers (e.g. morphine, codeine), therefore chasteberry may provide users with some pain relief by acting on similar pathways within the body [6, 7].

Chasteberry also stimulates the secretion of melatonin, a hormone in your body that regulates the circadian rhythm (sleeping patterns) [8].

Health Benefits of Chasteberry

1) Alleviates PMS

In many clinical studies, chasteberry reduced a variety of PMS symptoms including breast pain and tenderness, edema, constipation, irritability, depressed mood, anger, and migraines [1].

In one study of 128 women with PMS symptoms, more than half of the patients treated with chasteberry over 6 days for 6 consecutive menstrual cycles experienced significantly reduced breast pain and tenderness, edema, constipation, irritability, depressed moods, and migraines [9].

In some cases, PMS symptoms can be caused by an excess release of prolactin from the pituitary gland. In other cases, it may be a result of an imbalance of estrogen to progesterone [1].

High doses (400 mg daily) of chasteberry may alleviate PMS symptoms by reducing circulating prolactin in the body, which restores estrogen levels. Additionally, it reduces progesterone levels, normalizing the ratio of progesterone to estrogen. These hormonal balances may provide significant relief during PMS [10].

2) Enhances Female Fertility and Treats Menstrual Cycle Disorders

In Germany, chasteberry is used to treat luteal phase disorders. This is the second half of the menstrual cycle, which is usually shortened in women with the disorder [1].

Luteal phase disorder is primarily caused by progesterone deficiency in the first phase of the menstrual cycle. Another menstrual cycle disorder, called amenorrhea, is the absence of menstruation. This may be caused by sustained hormone fluctuations, thyroid malfunction, pituitary tumor, premature menopause, and pregnancy [11].

In both of these conditions, it is quite difficult and/or impossible to become pregnant. Patients also experience a variety of other complications, especially in their PMS cycles.

In a study of 96 patients with luteal phase disorders, amenorrhea and idiopathic infertility (unknown infertility), chasteberry increased pregnancy rates compared to placebo. Pregnancy occurred twice as often in patients who consumed chasteberry over a period of 3 months compared to patients who did not use chasteberry as a treatment [1].

These effects were mediated by normalizing the levels of progesterone. This helps to achieve pregnancy by alleviating progesterone deficiencies [1].

Further, patients can experience a more regular menstrual cycle. In one study of 52 women with hyperprolactinemia (higher than normal levels of circulating prolactin), chasteberry improved irregular periods and enhanced fertility. This was achieved by chasteberry normalizing the levels of prolactin in patients with hyperprolactinemia [12].

For these reasons, chasteberry may be effective in the treatment of polycystic ovarian syndrome [13].

3) Reduces Symptoms of Menopause

Menopause marks the end of the menstrual cycle for women. This period is associated with a natural decline in female reproductive hormones (estrogen and progesterone). In the time leading up to menopause, many women experience a variety of symptoms, including irregular periods, vaginal dryness, chills, night sweats, hot flashes, and dry skin.

In two separate trials (and surveys) totaling 75 patients, most women suffering from menopausal symptoms who used the essential oils derived from the leaf and fruit of chasteberry reported strong symptomatic relief from these menopausal symptoms [14].

Chasteberry increases progesterone at low doses (200 mg), which may be involved in reducing these symptoms of menopause [15].

4) May Reduce Migraines

In a 3 month study of 100 women with PMS and migraines, chasteberry treatment reduced the frequency of monthly migraines by more than 50 % in 42 % of patients. In addition, 57 % of patients given chasteberry had more than a 50 % lower frequency of monthly days with headaches [16].

5) May Act as an Insect Repellant

Chasteberry is effective in repelling insects such as fleas, mosquitos, ticks, and biting flies. In a lab, animal, and human studies, a spray developed from a seed extract of chasteberry (monk’s pepper) was successful in keeping away these insects from humans and animals for a time period of about 6 hours [17].

6) Is Anti-Inflammatory and May Reduce Symptoms of Endometriosis

Endometriosis is when the uterine-tissue lining (endometrium) begins to develop outside of the uterus. It is generally caused by genetic factors or hormonal imbalances. A common symptom of endometriosis is heavy inflammation around the uterus, resulting in pain and increased bleeding during the menstrual cycle [18].

Chasteberry may help reduce the amount of inflammation around the uterus by normalizing these hormonal imbalances, making the symptoms less painful [1, 19].

It can also relieve symptoms by decreasing pain and inflammation. In one rat study, a number of compounds in chasteberry reduced pain (possibly by stimulating opioid receptors) and inflammation in various parts of these animals [20].

In another lab study (human blood cells), chasteberry exhibited moderate anti-inflammatory activity [21].

7) May Treat Enlarged Prostate

An enlarged prostate, also known as benign prostatic hyperplasia (BPH), occurs in most men as they grow older. Although it is not cancer-causing, an enlarged prostate can significantly increase the risk of prostate cancer. The likelihood of prostate enlargement increases with age [22].

Enlargement occurs when cells of the prostate gland begin to multiply increasingly, eventually causing a noticeable size difference.

Prostate cancer can occur once the prostate gland cells begin to multiply out of control. In the lab, extracts of chasteberry reduced the growth of cells and even stimulated the death of prostate cells, indicating that chasteberry may be useful for the prevention and/or treatment of benign prostatic hyperplasia and human prostate cancer [23].

8) May Reduce Acne

One of the main causes of acne is hormonal fluctuation and imbalances, which are more pronounced during PMS. As a result, many women experience acne before their menstrual cycles. Because chasteberry normalizes these hormonal imbalances (by decreasing prolactin), it may treat premenstrual acne [24, 25, 26].

Chasteberry may also treat premenstrual acne due to its antibacterial and antioxidative properties. In the lab, gel extracts of chasteberry inhibited the growth of acne-producing bacteria (tested in cell plates) [27].

9) May Treat Uterine Fibroids

A uterine fibroid is a non-cancerous tumor that develops in the uterus of many women [R].

Most of the time, uterine fibroids are caused by hormonal imbalances. Because of this, hormone therapy is commonly used to treat and shrink uterine fibroids [28].

The key hormones involved in this process are generally estrogen and progesterone. High levels of progesterone can promote the development of uterine fibroids [28, 29].

Since chasteberry reduces progesterone levels, it may alleviate some symptoms of uterine fibroids.

Increased bleeding is one of the key symptoms of uterine fibroids. One study (DB-RCT) of 84 women with heavy bleeding in their uterus during menstruation found that chasteberry treatment for over a period of 4 months significantly decreased bleeding, indicating that it may reduce increased menstrual bleeding from patients with uterine fibroids [30].

Supplementing with Chasteberry


For PMS symptoms, uterine fibroids, premenstrual acne, endometriosis, and female infertility, 400 to 500 mg of standardized extract (with 0.5% agnuside) per day have been taken in clinical trials [1, 31].

For menopausal symptoms, low doses of about 200 mg per day were taken in clinical trials [1].

Agnuside is the active ingredient found in chasteberry, and powder extracts of chasteberry are generally standardized to contain 0.5% agnuside [31].

Natural Sources/Forms of Supplementation

Chasteberry can be found in a number of forms in your local store and online. The fruit is found in dried capsules as well as in liquid extracts. Most of the time it is mixed with other natural herbs, but can still be found in extracts of itself only.

Side Effects

If used in limited amounts (not more than 1000 mg per day), this fruit tends to be very well-tolerated and there have not been many reported side effects. In rare cases, there have been reports of skin rashes and stomach discomfort, while there are also reports of increased menstrual flow [1].

Do not take chasteberry during pregnancy, as this will cause hormonal fluctuations, which may have strong effects on an individual during this period.

Drug Interactions

Drug interactions or contraindications with chasteberry are unknown. However, because it increases dopamine, it may interfere with drugs that affect dopamine levels [1].

This would mainly apply to patients taking antipsychotic drugs and those who suffer from Parkinson’s disease. These individuals should consult their doctor before taking chasteberry.

Women taking other hormone-altering drugs such as birth control pills should not use chasteberry. Hormonal changes caused by chasteberry interrupt the action of these drugs. Furthermore, if you have a hormone-sensitive condition such as breast cancer, then chasteberry should be avoided [32].

Limitations and Caveats

The chasteberry has not received FDA approval as a health product, and it’s always recommended to speak with a healthcare provider while using this as a supplement.

High-quality clinical studies on chasteberry are limited and are small or of short duration. While some evidence supports the use of chasteberry for PMS and cyclical breast discomfort, evidence for its use in other conditions remains uncertain.

User Experiences

One female user reported that she had elevated prolactin levels, which can prevent pregnancy. She commented on the success she had from taking vitex, “I’ve tried it before and it works. My doctor was amazed to see an $8 herb do what a $130 medication does.”

Another female user with infertility had different results, “I used it with mixed results. The first 6 months it regulated me a lot better than I would be without it. But after the 6-month mark, my periods became further and further apart. However, I never got any side effects from it as I did from vitamins.”

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