There’s been a lot of hype in the past couple of years around chasteberry as a herbal supplement for women’s health. It’s touted to alleviate menopausal symptoms, reduce discomfort of PMS, and enhance fertility. Although this hormonal adaptogen has gained increasing popularity, it’s been used for centuries as a women’s health botanical.

Its first documented use was at least 2500 years ago in ancient Greece, and is also known as monk’s pepper. It’s about the size of a peppercorn, and produced by the chaste tree, which acquired its name because its fruit was likely used to decrease men’s libido during the Middle Ages. In Medieval Europe, monks took chasteberry because it was thought to lower their sexual desire. Fancy that?

Chasteberry, also known as Vitex agnus-castus is a large shrub (or small tree) native to Mediterranean and Asian areas, the berries are harvested from the dried ripe fruit of the chaste tree.


Chasteberry has been widely researched for its ability to reduce symptoms of PMS, and works by decreasing levels of the hormone prolactin. This helps rebalance other hormones, including estrogen and progesterone, which in turn reduces PMS symptoms.

In one study, women with PMS took chasteberry during three consecutive menstrual cycles. In total, 93 percent of those given the adaptogen reported a decrease in PMS symptoms, including a reduction in cravings, anxiety and depression.

That said, the study didn’t include a control group, so a placebo effect can’t be ruled out.

In two smaller studies, women with PMS were given 20 mg of Vitex agnus-castus per day or a placebo for three menstrual cycles Twice as many women in the chasteberry group reported a decrease in symptoms including irritability, mood swings, headaches, and breast tenderness (mastalgia), compared to those given the placebo. However, better-designed studies may be needed before strong conclusions can be made.


Chasteberry responds as a pituitary adaptogen: it’s been known to aid optimal estrogen and progesterone levels, or to calm excessive hormone secretion, thus helping restore balance to hormone levels. It’s able to bind to estrogen receptors and then exert biological activity of an estrogen. In addition to its estrogen-binding capabilities, chasteberry is also thought to correct progesterone balance by reducing the secretion of prolactin.

A 2011 study revealed how the daily incidence of hot flushes after 8 weeks of treatment was significantly decreased in women taking chasteberry compared with a group taking placebo. In addition, the group treated with chasteberry showed a statistically significant difference in terms of the severity of hot flushes, night-time sweating, insomnia, anxiety, depression, and headaches compared with the control group.

It’s important to note that some studies reporting menopausal benefits of chasteberry, subjects were provided with supplements that mixed chasteberry with other herbs – so it’s difficult to isolate the effects of chasteberry alone.


Before I go any further, chasteberry is not advised for patients undergoing fertility treatment with ovulation medications or while doing IVF. In women who are pregnant or are breast-feeding, the safety of chasteberry currently remains unproven.

Chasteberry has been shown to improve fertility, particularly for women with luteal phase defect (shortened second half of the menstrual cycle). This disorder is linked to abnormally high prolactin levels and makes it difficult for women to become pregnant.

In one study, 40 women with abnormally high prolactin levels were given either 40mg of chasteberry or a pharmaceutical drug. In this instance, chasteberry was as effective as the drug in reducing prolactin levels.

Another study reported that in 52 women with luteal phase defect, taking 20mg of chasteberry resulted in lower prolactin levels and prolonged menstrual phases, while participants given a placebo saw no benefits.

The supplement held a mix of other ingredients, making it difficult to isolate the positive effects of chasteberry, and more research is needed to strengthen evidence that chasteberry can assist with the treatment of infertility.


Mosquito repellent: Chasteberry has also been used as an insect repellent – in one study, an extract made from chasteberry seeds helped repel mosquitoes, flies, ticks, and fleas for about six hours.

Reduced headaches: Women prone to migraines were given chasteberry daily for three months – it reduced the number of headaches they experienced during their menstrual cycles by 66 percent. However, the study didn’t include a control group, making it impossible to know whether chasteberry alone was responsible for these benefits.

Bone repair: In one study, women with bone fractures given a combination of chasteberry and magnesium had slightly increased markers for bone repair compared with those given a placebo.


Chasteberry supplements are typically safe for most people when taken by mouth in appropriate dosages. Uncommon side effects include upset stomach, nausea, rashes, acne, itching, headaches, difficulty sleeping, and weight gain. When some women begin taking it, they notice a change in menstrual flow.

If you’re pregnant, have a hormone-sensitive health condition such as endometriosis or breast cancer, or if you have a history of mental illness or Parkinson’s disease, please talk to your doctor before taking chasteberry or any supplement in any form.

Chasteberry can interfere with some medications, including birth control, antipsychotics and estrogen supplements like those used with in-vitro fertilization treatments. Speak with your doctor before trying vitex if you are taking any of these medications.