Ingredient review

Vitex agnus-castus


What is it?

Vitex agnus-castus (VAC) is also commonly known as chaste tree or chasteberry. The plant’s main constituents include vitexin, casticin, agnuside, p-hydroxybenzoic acid, alkaloids, and diterpenoids. The fruit consists of flavonoids, terpenoids, neolignans, phenolic compounds, and glycerides. (20) Its main flavonoids include casticin, vitexin, and orientin. (8) Standardized extracts typically measure the iridoid or flavonoid content where aucubin (iridoid glycoside) or agnuside is used as the reference material. (9)

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Main uses

Premenstrual syndrome
Regulation of hormonal balance


Agnolyt ® (100 g of tincture provides 9 g of VAC with 1:5 ratio. A capsule contains dried extract of VAC fruit [9.58–11,5 : 1] 3.5–4.2mg) (5)
Considered as safe with no serious adverse events; 12 of 85 patients reported mild GI distress, skin manifestations or headaches, while 5 reported similarly in B6 group (13)
Agnucaston ® - BNO 1095 (70% ethanol, 30% H2O extract; 4 mg of extract equivalent to 40 mg of dry weight (10:1 ratio) VAC) (2) (25)
No adverse events over 3 menstrual cycles (12)
Agnugol ® (3.2-4.8 mg dried fruit extract ) (6)
No side effects over 8 weeks (6)
No side effects over 3 months as compared to metformin (24)
Prefemin® - Ze 440 (60% ethanol m/m, fruit extract ratio 6-12:1 standardized for casticin; 20 mg of extract equivalent to 120-240 mg of dry weight VAC) (22)
Equal instances (~5%) of reported adverse events between VAC (20 mg per day) and placebo groups with good tolerability over 3 cycles (22)
No serious adverse events with VAC (20 mg per day) over 3 cycles (18)
20/50 reported 37 adverse events, none serious in nature (20 mg per day) over 8 cycles (3)
Physicians suspected adverse events in 1% of patients with no serious effects. 94% of patients describe tolerance as good or very good (14)
Strotan ® (each capsule contains 20 mg of VAC) (16)
No side effects observed with VAC (20 mg) over 3 months (16)

Dosing & administration

Adverse effects

Vitex agnus-castus does not pose serious health risks and is considered safe. However, it is recommended that pregnant and lactating women avoid its use due to limited safety data in these states. Commonly reported side effects include nausea, headache, gastrointestinal disturbances, menstrual disorders, acne, pruritus, and erythematous rash. However, these side effects are mild and reversible. (4)(5)


The pharmacokinetics of VAC have been scarcely studied.


  • In mice, the oral bioavailability of agnuside was 0.7% with peak plasma concentrations achieved within 30-45 minutes of administration. (21)
  • In vitro, BNO 1095 (a VAC extract) solubility and permeability was improved once it was nano-emulsified, suggesting the possibility for improved bioavailability. (19)


  • In mice, agnuside was found in the highest amounts in the intestine, kidney, liver, spleen, brain, lungs and heart. (21)


  • No data is currently available.


  • No data is currently available.