Vitex (Chaste Tree Berry) | Supplementopedia

Overview

Vitex agnus‑castus, commonly called chaste tree or chaste‑tree berry, is a deciduous shrub native to the Mediterranean region. Its ripe fruits contain a complex mixture of phytochemicals that have been studied primarily for their ability to modulate the female endocrine system and support hormonal balance.

Benefits

Menstrual‑cycle regulation: Randomized controlled trials (RCTs) show a 60–80 % reduction in luteal‑phase symptoms (e.g., breast tenderness, irritability) after 3 months of 20–40 mg dried‑fruit extract daily.
Premenstrual syndrome (PMS) & dysmenorrhea: Meta‑analyses report significant decreases in PMS severity scores (‑2.5 ± 0.4 on a 10‑point scale) compared with placebo.
Menopause‑related hot flashes: Small‑scale trials report a 30 % reduction in frequency after 8 weeks of 30 mg daily.
Hyperprolactinemia: Vitex reduces prolactin by 10‑15 % in women with idiopathic hyperprolactinemia, often normalizing levels without dopamine‑agonist side effects.
Acne and seborrhea: Pilot studies suggest improved skin oiliness and lesion count, likely due to androgen‑modulating effects.
Premature lactation suppression: Limited evidence shows decreased milk volume when administered in the first 48 h postpartum (30 mg).
Mood support: Preliminary data suggest modest improvements in mood scores (‑1.2 ± 0.3 on the Hamilton Depression Rating Scale) in women with PMS‑related mood swings.

How It Works

Process: Vitex’s primary actions are mediated through the hypothalamic‑pituitary‑ovarian (HPO) axis.
Dopamine Agonism: The fruit’s flavonoids (e.g., apigenin, luteolin) and diterpenoids (e.g., vitexin, vitexic acid) act as dopamine‑type 2 receptor agonists, suppressing pituitary prolactin release.
Hormonal Cascade: Lowered prolactin removes inhibitory feedback on gonadotropin‑releasing hormone (GnRH), allowing normal pulsatile secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
Estrogen-Progesterone Balance: In the ovaries, this restores a more physiological estrogen‑progesterone ratio, dampening the “estrogen dominance” pattern often seen in PMS.
Progesterone-like Activity: Vitex also exhibits mild progesterone‑like activity via binding to progesterone receptors, contributing to uterine stability.
Anti-inflammatory Action: Anti-inflammatory flavonoids inhibit COX‑2 and NF‑κB pathways, reducing prostaglandin‑mediated uterine contractions.
Clinical Benefits: The combined endocrine and anti-inflammatory actions underlie the clinical benefits observed.

Dosage

Standardized Extract: Standardized dried‑fruit extract (20 % flavonoids): 20–40 mg per day (≈ 400–800 mg of a 20 %‑flavonoid extract) taken in the evening, as the herb’s effects are cumulative and benefit from nighttime dosing when prolactin peaks.
PMS/Menstrual-Cycle Support: 20 mg daily for 3 months, then reassess; some protocols use an initial 40 mg for the first 2 weeks to achieve steady‑state plasma levels.
Hyperprolactinemia: 40 mg daily for 4–6 weeks, then taper to 20 mg for maintenance.
Menopause Hot Flashes: 30 mg daily, preferably with food to improve absorption of lipophilic diterpenoids.
Special Populations: Adolescents (≥ 12 y) and pregnant women should use ≤ 20 mg under medical supervision.
Duration: Most studies employ 3–6 months; long‑term (>12 months) use should be monitored with periodic hormone panels.

Safety & Side Effects

General Tolerance: Vitex is generally well‑tolerated; the most common adverse events (≤ 5 % of users) are mild gastrointestinal upset, headache, or mild drowsiness.
Contraindications:
- Pregnancy (potential anti‑prolactin action may impair lactation)
- Lactation (may reduce milk production)
- Estrogen‑sensitive conditions (e.g., estrogen‑dependent breast cancer) because of its weak estrogenic activity
- Severe hepatic impairment (metabolism via hepatic CYP450 may be altered)
Drug Interactions:
- Dopamine‑agonist medications (e.g., bromocriptine) – additive prolactin suppression
- Hormonal contraceptives – possible reduction in efficacy
- Anti‑estrogenic agents (e.g., tamoxifen) – possible antagonism
Anticoagulant Caution: Caution is advised in patients on anticoagulants (e.g., warfarin) due to potential mild platelet‑aggregation inhibition.

Chemistry

Bioactive Constituents: The primary bioactive constituents are flavonoid glycosides (e.g., vitexin, isovitexin, apigenin‑7‑O‑β‑D‑glucoside) and diterpenoid acids (e.g., vitexic acid, agnuside).
Vitexin Formula: Vitexin’s formula is C₂₁H₂₀O₁₀ (IUPAC: 5,7‑dimethoxy‑2‑(4‑hydroxy‑3‑methoxy‑phenyl)‑4H‑chromen‑4‑one‑7‑O‑β‑D‑glucoside).
Flavonoid Backbone: The flavonoid backbone features a 2‑phenyl‑chromone core with hydroxyl and methoxy substituents that confer antioxidant and receptor‑binding properties.
Diterpene Structure: The diterpenes (e.g., vitexic acid, C₂₀H₂₈O₃) contain a labdane skeleton with a C‑13‑hydroxy group, contributing to the plant’s bitter taste and possible anti‑inflammatory activity.
Extract Composition: The overall extract contains > 20 % flavonoids (by weight) and ≤ 1 % essential oils (e.g., α‑pinene, β‑caryophyllene).
Standardization: The standardization to 20 % flavonoids ensures batch‑to‑batch consistency in clinical studies.

Sources & Quality

Cultivation: Vitex agnus‑castus is cultivated primarily in Greece, Turkey, and the North African Maghreb, where the climate mimics its native Mediterranean environment.
Harvesting: Commercial supplements typically use dried, ripe fruit harvested after full maturation, then dried under controlled temperature (< 45 °C) to preserve flavonoid integrity.
Extraction Methods: Extraction methods include ethanol‑water (70 % ethanol) maceration or super‑critical CO₂ extraction; the former yields higher flavonoid content, whereas CO₂ methods preserve volatile diterpenes.
Quality Control: Quality‑control standards (e.g., USP, EMA) require verification of flavonoid content (≥ 20 % total flavonoids) via HPLC‑UV, and testing for heavy metals, pesticide residues, and microbial load.
Preferred Sources: Certified organic or GMP‑certified sources are preferred to minimize contamination and ensure consistent pharmacological potency.