Monk's pepper


Order:  Mint order of flowering plants (Lamiales)

Family:  Mint family (Lamiaceae)

Subfamily:  Viticoideae

Genus:  Vitex

Origin and distribution:

Mediterranean region across Southwest Asia towards Krim and up to Pakistan

Effective ingredients:

Essential oil, flavonoids, iridoid glycosides, sesquiterpenes, triterpenes

Main areas of application in veterinary medicine:

Monk's pepper is used successfully in veterinary medicine as well to influence the hormonal balance positively, especially in animals with a strong sex drive, or to treat female animals with cycle disorders.

Main areas of application in human medicine:

Premenstrual syndrome, menstrual disorders, menopausal symptoms

Already in Greek history, monk's pepper (also known as chaste tree or chasteberry) appears as an anaphrodisiac (a remedy that dampens the sex drive). It got the name chaste tree in the Middle Ages. The plant was mainly cultivated in monastery gardens and taken by monks to facilitate compliance with their vows of chastity. The chaste tree became the symbol of the abstinence that marked a monk's life. Today, chaste tree is mainly used in the treatment of typical gynaecological disorders, such as PMS (premenstrual syndrome, complex physical and emotional complaints related to the menstrual cycle).

The combined effect of the active substances is cycle-regulating and directly influences the prolactin level in the blood, which i.a. controls the production of luteal hormones that prepare the uterus for implantation of the fertilised egg. Without luteal hormones, the entire cycle gets out of balance and inhibits fertility.

A study has shown that active ingredients of the monk's pepper attach to the opioid receptor, which could explain why the monk's pepper provides relief for premenstrual syndrome symptoms.

Scientifically, the mechanism of action is not entirely clear yet. In low doses, the monk's pepper inhibits the activation of dopamine receptors, which leads to an increase in prolactin release, which in turn leads to a lowering of the corpus luteum hormone. In higher doses, monk's pepper causes slightly lower levels of prolactin. The diterpenes, with their effect similar to that of dopamine, are probably the effective agent here. In women, lowering prolactin affects FSH (folic stimulating hormone) and oestrogen levels, and in men it lowers testosterone levels.

So far, no serious adverse effects have been reported. Studies have reported occasional occurrence of headache, skin reactions and gastrointestinal complaints.

Alternative names:

Chaste tree, chasteberry, chaste lamb, tanis

Compiled by: Hannah Novak on 19/06/2019 


  • D.E. Webster, J.Lu, S.-N.Chen, N.R. Farnsworth, Z.Jim Wang: Activation of the μ-opiate receptor by Vitex agnus-castus methanol extracts: Implication for its use in PMS, Journal of Ethnopharmacology. Volume 106, No. 2, 2006, p. 216-221
  • D.E. Webster, Y.He, S.N. Chen, G.F. Pauli, N.R. Farnsworth, Z.J. Wang: Opioidergic mechanisms underlying the actions of Vitex agnus-castus L., Biochemical Pharmacology, Band 81, Nr. 1, 1. Januar 2011, D. 170-177