Vitex — Vitex agnus-castus

Common & Latin Names

Common names: Vitex, Chaste tree, Chasteberry, Monk’s pepper, Abraham’s balm, Agnus castus Latin name: Vitex agnus-castus L. TCM name: Man Jing Zi (蔓荆子) — though this more commonly refers to Vitex trifolia/rotundifolia. V. agnus-castus is used in modern integrative TCM practice but is not a classical Chinese herb. German: Monchspfeffer (Monk’s pepper) Italian: Agnocasto

Plant Family & Parts Used

Family: Lamiaceae (mint family — reclassified from Verbenaceae based on molecular phylogenetics) Parts used: Ripe fruit (berries) — the small, dark, peppercorn-sized dried fruits are the medicinal part. The berries have a peppery, slightly bitter taste (hence “Monk’s pepper”). Leaves and flowers have also been used traditionally but are not the focus of clinical research. Habitat: Native to the Mediterranean basin and Central Asia. Grows along riverbanks, coastal areas, and in moist, well-drained soils. Naturalized in the southeastern United States and parts of Australia. A deciduous shrub or small tree growing to 5-8 meters. The name “chaste tree” derives from the ancient belief that the plant suppressed libido — Athenian women placed the leaves in their beds during the Thesmophoria festival to maintain chastity, and medieval monks consumed the berries to suppress desire.

Traditional Uses

Greco-Roman Medicine (2,500+ years)

Vitex has one of the oldest documented gynecological uses of any plant. Hippocrates (4th century BCE) recommended it for injuries, inflammation, and diseases of the spleen. Dioscorides (1st century CE) described it in De Materia Medica for calming sexual desire, promoting lactation, and treating uterine disorders. Pliny the Elder wrote that Roman matrons used the leaves to suppress lust and that Vestal Virgins carried branches of vitex.

The Greco-Roman association with chastity was not merely symbolic — vitex genuinely affects the hypothalamic-pituitary-gonadal axis, reducing prolactin and modifying sex hormone levels. The ancients observed the clinical effects without understanding the mechanism.

Medieval European Medicine

Medieval monks consumed vitex berries as a “Monk’s pepper” to suppress sexual desire and maintain celibacy — giving the plant its most enduring common name. This was one of the most widely used herbs in monastery gardens. Hildegard von Bingen described it as a remedy for menstrual complaints. The herbal tradition maintained continuous use of vitex for women’s reproductive issues throughout the Middle Ages and Renaissance.

Eclectic Medicine (19th Century)

American Eclectic physicians adopted vitex from European tradition. It was primarily used for amenorrhea, dysmenorrhea, and to promote lactation. The Eclectics recognized its specific affinity for the female reproductive system.

Modern German Phytomedicine

Vitex’s modern clinical renaissance began in Germany in the 1950s when Gerhard Madaus conducted the first pharmacological studies. Commission E approved vitex for menstrual cycle irregularities, premenstrual complaints, and mastodynia (breast pain) in 1992. Germany has produced the majority of clinical evidence on vitex, and standardized vitex extracts (Ze 440, BNO 1095) are registered pharmaceuticals in Germany, Austria, and Switzerland.

Active Compounds & Pharmacology

Primary Phytochemicals

Iridoid glycosides: Agnuside (0.6% — often used as a standardization marker), aucubin. These contribute to anti-inflammatory and hormone-modulating effects.

Diterpenes (labdane and clerodane types): Rotundifuran, vitexilactone, vitexin. These are the primary dopaminergic compounds — they bind to dopamine D2 receptors in the pituitary, mediating the prolactin-lowering effect that is central to vitex’s mechanism.

Flavonoids: Casticin, penduletin, chrysosplenol D, apigenin. Anti-inflammatory, anti-estrogenic, and progesterone-supporting effects.

Essential oil (0.5-1.3%): 1,8-cineole, sabinene, alpha-pinene, beta-caryophyllene. Anti-inflammatory and antimicrobial.

Fatty acids: Stearic acid, oleic acid, linoleic acid, palmitic acid — in the oily seed.

Mechanisms of Action

1. Dopamine D2 Receptor Agonism (Prolactin Suppression): The most important and best-characterized mechanism. Diterpene compounds in vitex bind to dopamine D2 receptors on pituitary lactotroph cells, suppressing prolactin release. Elevated prolactin (even within the “normal” range) is associated with luteal phase defects, irregular cycles, PMS, mastalgia, and infertility. By reducing prolactin, vitex restores normal progesterone production in the luteal phase (Milewicz et al., 1993).

2. Mu-Opioid Receptor Activity: Vitex compounds interact with mu-opioid receptors. This may contribute to analgesic effects and further modulate the HPG axis (the hypothalamic-pituitary-gonadal axis is regulated in part by opioid peptides).

3. Progesterone-Favoring Hormonal Shift: Vitex does not contain progesterone or phytoestrogens in significant amounts. Instead, it favors progesterone production indirectly through prolactin suppression: lower prolactin allows stronger corpus luteum function, increasing endogenous progesterone in the luteal phase. This shifts the estrogen-to-progesterone ratio toward progesterone — addressing relative estrogen dominance.

4. Beta-Endorphin Modulation: Vitex increases beta-endorphin levels, which may explain mood-improving effects in PMS and PMDD.

5. FSH/LH Ratio Modulation: By modulating dopamine and prolactin signaling, vitex normalizes the FSH/LH ratio. This is relevant in conditions like PCOS where LH is disproportionately elevated relative to FSH.

Clinical Evidence

Key Clinical Trials

Milewicz, A., Gejdel, E., Sworen, H., et al. (1993). “Vitex agnus castus extract in the treatment of luteal phase defects due to latent hyperprolactinemia. Results of a randomized placebo-controlled double-blind study.” Arzneimittelforschung, 43(7), 752-756.

• 52 women with luteal phase defects due to latent hyperprolactinemia
• Vitex agnus-castus extract 20mg daily vs. placebo for 3 months
• Results: Significant reduction in prolactin release, normalization of luteal phase length, restoration of normal progesterone levels, and normalization of cycle deficits
• This landmark study established the dopaminergic/prolactin-lowering mechanism as the basis for vitex’s clinical effects
• 2 pregnancies occurred in the vitex group during the study (a positive outcome for these infertility patients)

Westphal, L.M., Polan, M.L., Trant, A.S., & Mooney, S.B. (2004). “A nutritional supplement for improving fertility in women: a pilot study.” Journal of Reproductive Medicine, 49(4), 289-293.

• Prospective pilot study of a fertility-promoting nutritional supplement containing vitex, green tea, L-arginine, and vitamins
• 93 women who had attempted to conceive for 6-36 months without success
• After 3 months: 14 pregnancies (33% of completers vs. expected rate <10%)
• After 6 months: additional 12 pregnancies
• While a multi-ingredient study, vitex was the primary hormonal agent, and the results aligned with vitex’s known mechanism of improving luteal function

van Die, M.D., Burger, H.G., Teede, H.J., & Bone, K.M. (2013). “Vitex agnus-castus extracts for female reproductive disorders: a systematic review of clinical trials.” Planta Medica, 79(7), 562-575.

• Systematic review of 12 clinical trials (8 RCTs) involving vitex for female reproductive disorders
• Found consistent evidence for efficacy in PMS/PMDD (5 positive RCTs)
• Supported efficacy in menstrual cycle irregularities (amenorrhea, oligomenorrhea)
• Evidence for luteal phase defect correction and latent hyperprolactinemia
• Emerging evidence for mastalgia (cyclical breast pain) and fertility enhancement
• Concluded that “vitex agnus-castus is a well-tolerated herbal medicine with sufficient evidence for its role in PMS treatment”

Schellenberg, R. (2001). “Treatment for the premenstrual syndrome with agnus castus fruit extract: prospective, randomised, placebo controlled study.” BMJ, 322(7279), 134-137.

• 170 women with PMS, vitex extract (Ze 440, 20mg) vs. placebo for 3 cycles
• Vitex significantly superior to placebo in reducing PMS symptoms (p<0.001)
• All symptom clusters improved: irritability, mood alteration, anger, headache, breast fullness
• 52% of vitex group rated themselves as “much improved” vs. 24% in placebo
• Published in the BMJ — rare for an herbal medicine trial, indicating the strength of the evidence

Zamani, M., Neghab, N., & Torabian, S. (2012). “Therapeutic effect of Vitex agnus castus in patients with premenstrual syndrome.” Acta Medica Iranica, 50(2), 101-106.

• 128 women with PMS, vitex drops (40 drops daily) vs. placebo for 6 days/cycle for 6 cycles
• Significant reduction in PMS symptoms including bloating, mood changes, breast tenderness, and irritability
• Consistent with the larger evidence base supporting vitex for PMS

Therapeutic Applications

Conditions

• Premenstrual syndrome (PMS) and PMDD: Strongest evidence base — reduces irritability, breast pain, mood changes, bloating, headache
• Luteal phase defect: Restores luteal phase length and progesterone production via prolactin reduction
• Female infertility (related to luteal insufficiency/hyperprolactinemia): Improves conception rates
• Menstrual irregularities: Amenorrhea, oligomenorrhea, polymenorrhea — cycle regulation
• Cyclical mastalgia (breast pain): Reduces prolactin-driven breast tenderness
• Latent hyperprolactinemia: Normalizes prolactin without pharmaceutical dopamine agonists
• Acne (hormonal, premenstrual): Via androgen modulation and progesterone support
• Perimenopause: Cycle regulation during the transition (used for irregular periods, not hot flashes)
• PCOS (adjunctive): Normalizes LH/FSH ratio, supports progesterone

Dosage Ranges

• Standardized extract (Ze 440): 20mg daily (standardized to 60% ethanolic extract — the most studied form)
• Standardized extract (BNO 1095): 4mg daily (a more concentrated extract; standardized differently)
• Dried berry powder: 500-1000mg daily
• Tincture (1:5 in 60% alcohol): 2-4mL daily (40-80 drops)
• Fluid extract (1:1): 0.5-1mL daily

Forms and Timing

Take in the morning (prolactin release follows a circadian rhythm with nocturnal peaks; morning dosing allows the dopaminergic effect to modulate the daily prolactin cycle). Take on an empty stomach for best absorption. Effects typically require 3-6 months of continuous use — vitex works through gradual hormonal rebalancing, not acute effects. It should be taken daily throughout the entire menstrual cycle, not only during specific phases.

Safety & Contraindications

Generally Well Tolerated

Clinical trials report adverse effects comparable to placebo. In the Schellenberg (2001) BMJ trial with 170 women, side effects were mild and rare (GI discomfort, headache, skin reactions — all <4%).

Contraindications

• Pregnancy: Discontinue once pregnancy is confirmed. While vitex is used to achieve pregnancy, its hormonal effects should not continue during pregnancy. Some traditional herbalists recommend continuing through the first trimester to prevent miscarriage in women with known progesterone deficiency, but this is controversial and requires practitioner supervision.
• Dopamine agonist medications (bromocriptine, cabergoline, levodopa): Additive dopaminergic effects. Avoid concurrent use.
• Dopamine antagonist medications (antipsychotics — haloperidol, risperidone, olanzapine): Vitex may counteract the therapeutic effects of drugs that work by blocking dopamine receptors. Contraindicated.
• Hormone-sensitive conditions: While vitex is not estrogenic, its hormonal-modulating effects warrant caution in estrogen receptor-positive cancers. The evidence is actually reassuring (vitex favors progesterone over estrogen), but conservative guidance applies until more data is available.
• In vitro fertilization (IVF) and hormonal fertility treatments: Vitex may interfere with precise hormonal control required during IVF protocols. Discontinue during medically managed fertility cycles.

Drug Interactions

• Oral contraceptives: Vitex may alter the efficacy of hormonal contraception by modifying the HPG axis. Avoid concurrent use or ensure adequate counseling.
• HRT (hormone replacement therapy): Potential for altered hormone dynamics. Use with caution.
• Metoclopramide: This dopamine antagonist’s anti-nausea mechanism may be reduced by vitex.

Side Effects (Uncommon)

Mild GI discomfort, headache (transient), skin reactions (rare), increased menstrual flow (temporary — typically resolves as cycles normalize), and paradoxical worsening of PMS symptoms in the first 1-2 cycles (common — usually indicates the herb is recalibrating the hormonal axis).

Energetics

TCM Classification (Modern Integration)

• Temperature: Slightly warm
• Flavor: Acrid, bitter
• Meridian entry: Liver, Kidney, Ren (Conception Vessel), Chong (Penetrating Vessel)
• Actions: Courses Liver Qi, regulates the Chong and Ren Mai, supports Kidney Yang (specifically the Kidney’s role in menstrual cycle regulation), clears damp-heat from the Lower Jiao
• TCM pattern correspondence: Liver Qi stagnation affecting the Chong and Ren (PMS, irregular cycles, breast distension), Kidney Yang deficiency with Liver stagnation (luteal phase defect, infertility), Phlegm-damp in the uterus (PCOS pattern)

Ayurvedic Classification

• Rasa (taste): Katu (pungent), Tikta (bitter)
• Virya (energy/potency): Ushna (mildly warming)
• Vipaka (post-digestive effect): Katu (pungent)
• Dosha effects: Pacifies Kapha (moves stagnation, reduces dampness). Regulates Vata in the Apana Vayu (the downward-moving Vata governing menstruation and reproduction). May mildly increase Pitta in excess.
• Dhatu affinity: Shukra (reproductive tissue — its primary site of action), Rakta (blood), Rasa (plasma)
• Srotas affinity: Artavavaha (menstrual/reproductive channels — the primary srotas affected)

Functional Medicine Integration

Vitex is the premier botanical intervention for HPG axis regulation in functional medicine women’s health protocols. Its mechanism of action — dopaminergic prolactin suppression leading to improved luteal function — is precise and well-characterized.

PMS/PMDD Protocol

Vitex is the first-line botanical for PMS in functional medicine, with NNT (number needed to treat) of approximately 4-6 based on clinical trial data. It addresses the root hormonal mechanism (luteal insufficiency from subclinical hyperprolactinemia) rather than merely managing symptoms. In a comprehensive PMS protocol, vitex provides the hormonal foundation while magnesium, B6, calcium, and stress management address cofactors.

Female Infertility Protocol (Ovulatory/Luteal Defects)

For women with luteal phase defects (short luteal phase, low mid-luteal progesterone, spotting before menses), vitex restores corpus luteum function by normalizing prolactin. This is a specific, testable mechanism — mid-luteal progesterone levels and luteal phase length can be tracked to verify response. Vitex is typically combined with fertility-supporting nutrients (folate, zinc, CoQ10, vitamin D) and lifestyle interventions.

Estrogen Dominance Protocol

Many functional medicine patients present with relative estrogen dominance — not necessarily high absolute estrogen, but a progesterone-to-estrogen ratio that favors estrogen. Symptoms include PMS, fibroids, endometriosis, heavy periods, breast tenderness, and mood instability. Vitex addresses this by boosting the progesterone side of the ratio via luteal support, complementing DIM/I3C (which supports estrogen metabolism on the clearance side).

PCOS Protocol (Adjunctive)

In PCOS, vitex may help normalize the LH/FSH ratio and support ovulation in patients with oligomenorrhea. It is not the primary intervention for PCOS (which is fundamentally insulin-driven), but it addresses the neuroendocrine component as an adjunct to berberine, inositol, and lifestyle interventions.

Perimenopause Protocol

During the perimenopause transition, cycles become increasingly irregular as ovarian reserve declines. Vitex can help regulate cycles in early perimenopause by supporting whatever luteal function remains. It is not indicated for late perimenopause or postmenopause (when the issue is ovarian insufficiency rather than luteal defects).

Four Directions Connection

Primary Direction: Jaguar (West — Emotional Healing)

Vitex is quintessentially Jaguar medicine. PMS and PMDD are, at their core, emotional-hormonal experiences — the monthly confrontation with the shadow self, the feelings that surface when progesterone drops and the neurochemical cushion thins. The Jaguar governs this territory: the emotional body, the shadow, the feelings we suppress all month that emerge in the premenstrual window. Vitex does not suppress these feelings — it restores the hormonal foundation that allows women to navigate them with resilience rather than being overwhelmed. The Jaguar teaches us not to flee from our emotions but to have the strength to face them. Vitex provides this strength at the biochemical level.

Secondary Direction: Serpent (South — Physical Body)

Vitex’s physical effects — cycle regulation, fertility enhancement, breast pain relief — are Serpent medicine. The reproductive system is the deepest expression of the Serpent’s domain: the body’s capacity for creation, for bringing new life. When the reproductive axis is disrupted, the Serpent’s fundamental creative power is compromised. Vitex restores this power by correcting the HPG axis from the top (pituitary prolactin) down to the bottom (corpus luteum progesterone).

Tertiary: Hummingbird (North — Ancestral Wisdom)

Vitex has been used for women’s reproductive health for 2,500 years — from Hippocrates to medieval monasteries to German pharmaceutical companies to modern functional medicine clinics. The Hummingbird’s teaching is that ancestral wisdom, when investigated with modern tools, often reveals precise and verifiable mechanisms. The ancient observation that vitex “regulates the menses” turns out to be a dopaminergic, prolactin-mediated, luteal-supporting mechanism — but the clinical observation was correct all along.

References

1. Milewicz, A., Gejdel, E., Sworen, H., et al. (1993). Vitex agnus castus extract in the treatment of luteal phase defects due to latent hyperprolactinemia. Arzneimittelforschung, 43(7), 752-756.

2. Westphal, L.M., Polan, M.L., Trant, A.S., & Mooney, S.B. (2004). A nutritional supplement for improving fertility in women: a pilot study. Journal of Reproductive Medicine, 49(4), 289-293.

3. van Die, M.D., Burger, H.G., Teede, H.J., & Bone, K.M. (2013). Vitex agnus-castus extracts for female reproductive disorders: a systematic review of clinical trials. Planta Medica, 79(7), 562-575.

4. Schellenberg, R. (2001). Treatment for the premenstrual syndrome with agnus castus fruit extract: prospective, randomised, placebo controlled study. BMJ, 322(7279), 134-137.

5. Zamani, M., Neghab, N., & Torabian, S. (2012). Therapeutic effect of Vitex agnus castus in patients with premenstrual syndrome. Acta Medica Iranica, 50(2), 101-106.

6. Wuttke, W., Jarry, H., Christoffel, V., Spengler, B., & Seidlova-Wuttke, D. (2003). Chaste tree (Vitex agnus-castus) — pharmacology and clinical indications. Phytomedicine, 10(4), 348-357.

7. Jarry, H., Spengler, B., Porzel, A., et al. (2003). Evidence for estrogen receptor beta-selective activity of Vitex agnus-castus and isolated flavones. Planta Medica, 69(10), 945-947.

8. Berger, D., Schaffner, W., Schrader, E., Meier, B., & Brattstrom, A. (2000). Efficacy of Vitex agnus castus L. extract Ze 440 in patients with pre-menstrual syndrome (PMS). Archives of Gynecology and Obstetrics, 264(3), 150-153.

9. Daniele, C., Thompson Coon, J., Pittler, M.H., & Ernst, E. (2005). Vitex agnus castus: a systematic review of adverse events. Drug Safety, 28(4), 319-332.

10. Webster, D.E., He, Y., Chen, S.N., et al. (2011). Opioidergic mechanisms underlying the actions of Vitex agnus-castus L. Biochemical Pharmacology, 81(1), 170-177.