Vitex Chasteberry
Also known as: Chasteberry, Chaste tree, VAC, Vitex agnus-castus
Overview
Vitex agnus-castus (VAC), commonly known as Chasteberry, is a fruit extract derived from the chaste tree, widely utilized as an herbal supplement. It is primarily recognized for its traditional and contemporary application in addressing female reproductive health concerns, particularly premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD). VAC is sought after for its potential to alleviate a range of PMS symptoms, including mood swings, breast tenderness, and irritability. Research on VAC's efficacy is moderately mature, with several randomized controlled trials (RCTs) and meta-analyses supporting its use. However, the quality and consistency of these studies vary, with some exhibiting a high risk of bias and heterogeneity, which can limit definitive conclusions.
Benefits
Vitex agnus-castus (VAC) primarily benefits women experiencing premenstrual syndrome (PMS) symptoms. A meta-analysis of three high-quality randomized controlled trials (RCTs) involving 520 participants demonstrated that women taking VAC were 2.57 times more likely to achieve symptom remission compared to a placebo group (95% CI 1.52-4.35). Another comprehensive meta-analysis, encompassing 14 RCTs, reported a significant pooled effect size (Hedges g = -1.21; 95% CI -1.53 to -0.88) favoring VAC over placebo for overall PMS symptom reduction, although this finding was accompanied by high heterogeneity (I²=91%). VAC may also be beneficial in reducing mild hyperprolactinaemia, a condition linked to various reproductive symptoms, though its effects are dose-dependent and somewhat inconsistent across studies. Additionally, there is potential for VAC to improve symptoms associated with premenstrual dysphoric disorder (PMDD), although diagnostic variability in studies complicates a definitive interpretation of this benefit.
How it works
Vitex agnus-castus (VAC) is believed to exert its therapeutic effects primarily by influencing dopaminergic pathways. This action leads to a reduction in prolactin secretion from the pituitary gland, which may alleviate PMS symptoms often associated with elevated prolactin levels (hyperprolactinaemia). Beyond prolactin modulation, VAC may also interact with the hypothalamic-pituitary-ovarian axis, potentially helping to balance estrogen and progesterone effects. The active phytochemicals responsible for these actions include flavonoids and iridoid glycosides, which are thought to influence neurotransmitter receptors and hormone secretion. While the exact bioavailability of all compounds is not fully characterized, standardized extracts, such as Ze 440, are commonly used in clinical trials to ensure consistent and measurable dosing.
Side effects
Vitex agnus-castus (VAC) is generally considered safe and well-tolerated when used by women for PMS. Common side effects, occurring in less than 5% of users, are rare and typically mild, including gastrointestinal discomfort or headache. Uncommon side effects, affecting 1-5% of users, may include skin rash or other allergic reactions. While no major drug interactions have been conclusively reported, caution is advised when VAC is used concurrently with dopamine agonists or antagonists due to its known dopaminergic effects. This is because VAC can influence dopamine receptors, potentially altering the effects of medications that also act on these pathways. Contraindications for VAC include pregnancy and breastfeeding, as there is insufficient safety data to support its use in these populations. Therefore, pregnant or breastfeeding individuals should avoid using Vitex agnus-castus.
Dosage
Effective doses of Vitex agnus-castus (VAC) in clinical trials typically range from 20 mg to 40 mg of a standardized extract, such as Ze 440, taken daily. The minimum effective dose appears to be around 20 mg per day, with noticeable benefits usually observed after consistent use over 2 to 3 menstrual cycles. While there is no established maximum safe dose, studies have shown that higher doses can have variable effects on prolactin levels, and not necessarily increased efficacy. Regarding timing, studies commonly involve daily dosing throughout the entire menstrual cycle or specifically during the luteal phase. The form of the supplement and its absorption characteristics can influence efficacy, which is why standardized extracts are preferred in research to ensure consistent active compound delivery.
FAQs
Is VAC safe for long-term use?
Limited long-term data exist, but short to medium-term use (up to 3-6 months) is generally considered safe and well-tolerated.
When do benefits appear?
Symptom improvement is typically reported after consistent use for 2 to 3 menstrual cycles, as its effects are gradual.
Can VAC replace hormonal treatments?
VAC shows efficacy for PMS but is not a direct substitute for hormonal therapies in severe cases; comparative trials are limited.
Does VAC affect fertility?
There is no clear evidence of adverse effects on fertility; some suggest it may support hormonal balance, but more research is needed.
Research Sources
- https://pubmed.ncbi.nlm.nih.gov/31780016/ – This meta-analysis of three high-quality RCTs (n=520) found that women taking Vitex agnus-castus were 2.57 times more likely to experience PMS symptom remission compared to placebo. The study highlights the need for more CONSORT-compliant trials to solidify these findings.
- https://pubmed.ncbi.nlm.nih.gov/28237870/ – This systematic review and meta-analysis of 14 RCTs reported a large pooled effect size (Hedges g = -1.21) favoring Vitex agnus-castus for total PMS symptom reduction. However, it noted high heterogeneity (I²=91%) and suspected publication bias, suggesting caution in interpretation.
- https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2023.1269781/full – This systematic review explored Vitex agnus-castus's effect on hyperprolactinaemia. It indicated that VAC might reduce prolactin levels in a dose-dependent manner, though results were mixed across small studies with methodological differences in prolactin measurement, suggesting preliminary evidence.
