Products
Monk’s pepper extracts are commercially available as film-coated tablets and drops, among others.
Stem plant
Monk’s pepper L. belongs to the verbenaceae family. The shrub, which grows up to several meters high, is native to the Mediterranean region, Central Asia and India. Monk’s pepper has been used since ancient times to treat women’s ailments. The name of the plant comes from the Middle Ages. The expensive pepper was replaced by the monks with crushed Agnus castus fruits, which look and taste similar to pepper fruits. “Chaste lamb” (agnus-castus, Latin agnus “the lamb” and castus “pure, chaste”) was also used as a libidinal agent at that time.
Medicinal drug
The medicinal drug used is the ripe and dried fruits (Agni casti fructus), which are usually processed into a standardized ethanolic dry extract (Agni casti extractum ethanolicum siccum). The leaves (Agni casti folium) and other plant parts are rarely used.
Ingredients
Monk’s pepper contains iridoid glycosides (e.g., agnuside, aucubin), flavonoids (e.g., casticin, isovitexin, orientin), essential oil (mono- and sesquiterpenes), diterpenes (vitexilactone), and fatty oil, among others.
Effects
The mechanism of action has not been fully elucidated. The effects of monk pepper are attributed in part to dopaminergic and prolactin-lowering properties, which counteracts underlying hyperprolactinemia. As a result of binding to the dopamine D2 receptors, prolactin levels are lowered and FSH and LH release are normalized. Involvements of other receptors and systems are discussed, e.g., activity at histamine H1, estrogen, endorphin, opioid, and acetylcholine receptors. Some clinical studies are available. We cannot make any conclusive statement on the actual efficacy.
Indications
For the internal treatment of premenstrual syndrome and menstrual rhythm disorders (menstrual tempo abnormalities, e.g., after taking oral contraceptives). Other indications mentioned in the literature include acne, absence of menstruation, leakage of breast milk without pregnancy, hyperprolactinemia, insufficient milk production, rosacea, luteal insufficiency, menopausal symptoms, and infertility. Monk’s pepper is not officially approved for this purpose by authorities in many countries.
Dosage
According to the package insert. Finished medicines are usually taken regularly without interruption once a day for at least 3 months. They should also be administered during menstruation. The drug drug is hardly used in practice.
Contraindications
Monk’s pepper is contraindicated in hypersensitivity, during pregnancy and lactation. It is also not recommended for use in the presence of prolactinoma. For complete precautions, see the drug label.
Interactions
Dopamine antagonists may theoretically abolish the dopaminergic effects of monk’s pepper, and dopamine agonists may potentiate them.
Adverse effects
Rarely, indigestion, vomiting, hypersensitivity reactions, dry mouth, headache, fatigue, acne, and itching occur at the beginning of treatment. If rashes and itching occur, treatment must be discontinued.