Agnus castus Benefits

Agnus castus
Latin Name

Agnus castus

Also Known As

Vitex, Monk's pepper, Wild pepper, Chaste Tree


Native Mediterranean plant

Parts Used

Fruits (berries)

Traditional Use and Health Benefits

This pretty tree bears fruit that has a long history of use for gynaecological complaints, as well as an alleged history of use by medieval monks to quell sexual desire – hence Agnus Castus’s aliases, “chasteberry” and “monk’s pepper”.  

Conversely, it also has a reputation as an aphrodisiac, with Greek philosopher and naturalist Plato describing its aphrodisiac effects, a seeming contradiction to the aforementioned anaphrodisiac qualities it was used for by the monks. It is thought that the Chasteberry is able to both dampen and heighten sexual desire because it is an adaptogen. This means it works to normalize hormone imbalance through its effect on the adrenal glands, in this case the pituitary - in other words, it restricts hormonal excesses.

Agnus Castus Benefits


Perhaps the most famous use of this adaptogenic herb is as an aid to the various maladies that can befall women as part of their monthly cycles. Much research has been conducted with this plant, with quite promising results. One such study of German gynaecologists evaluated the effect of an Agnus Castus preparation on 1542 women diagnosed with PMS (pre-menstrual syndrome). The women took the preparation for 166 days, with 90% reporting relief of symptoms after an average treatment duration of 25.3 days.

In another 3 month trial by Coeugniet, et al treated 36 patients with PMS with a dose of 40 drops of tincture per day. This produced a reduction in headaches, breast tenderness, bloating and fatigue. Improvement in anxiety, mood swings and other psychological symptoms were also reported.

Herbalists believe the Chasteberry is a natural source of progesterone that can help to balance the ratio of oestrogen to progesterone. It has been used to successfully jump start the regular menstrual cycle and can be especially useful when coming off the birth control pill.

Miscarriage and Infertility

Since progesterone plays a crucial role in conception and sustaining pregnancy, Agnus Castus may also be a first step before trying infertility treatments. Progesterone is needed to thicken the uterine lining, and help with luteal phase defects—the period between ovulation and menstruation during a woman’s menstrual cycle which is typically 10-17 days long. When there is an insufficient luteal phase, it can lead to problems with conception and miscarriage.

In one clinical trial, 48 women (ages 23 to 39) who were diagnosed with infertility took Chasteberry once daily for three months. During the three-month trial period, seven women became pregnant and 25 women experienced normalized progesterone levels, which can increase the chances for pregnancy.


Some studies have shown that the use of Agnus Castus extract may also help with the symptoms of perimenopause, the earliest stage of menopause. The hormone balancing qualities of this herb make it ideal for counteracting hot flushes and other symptoms. It can also be combined with other herbs such as Black cohosh or Dong Quai for maximum effect.

Agnus Castus contains compounds that send the pituitary gland a signal to increase luteinizing hormone production and decrease the amount of hormones being produced to stimulate follicle growth. Indirectly, this makes progesterone production spike. This is beneficial to pre-menopausal, peri-menopausal and menopausal women, as during these stages progesterone levels fall, making oestrogen – previously on par with progesterone – the most dominant hormone. This imbalance is responsible for the feelings of anxiety, stress and panic associated with the menopause, in addition to tension headaches, palpitations and digestive problems.

Typical Use

Most studies conducted have been done with Agnus Castus tincture, the standard dose is 40 drops daily for at least 12 weeks. Chaste tree is a slow acting herb, it usually takes several months to show benefit, except in cases of lactation, which often improve within a few weeks.

Agnus castus Tincture
Made with dry herb
Take 2-3 mls of Tincture 2-3 times per day.

Folklore and History

Chasteberry was well known to leading ancient Greek physicians. Hippocrates commented, "If blood flows from the womb, let the woman drink dark wine in which the leaves of the Vitex have been steeped." Pliny the Elder said, "The trees furnish medicines that promote urine and menstruation." The herb was widely used throughout Europe, and appeared in Homer's 6th century BCE epic, The Iliad.

For unknown reasons, Agnus Castus is not found in many Western herbals until the middle of the 1900s. Prior to that time it was not considered a primary herb in the US medical botany, Eclectic, or herbal literature. It is mentioned briefly by Felter and Lloyd in King’s American Dispensatory as a galactogogue, emmenagogue, and aphrodisiac.

Agnus castus

Bitters, alkaloids, volatile oil.


Agnus castus has never been linked to any significant side effects, but minor problems are possible. Stomach upsets, itching and rashes have been noted. Agnus Castus must not be given to prepubesant girls.