Chaste Tree (Vitex agnus-castus)

Traditional texts describe the preparations below, and where those texts give specific amounts, the amounts are quoted here as part of that record. This is a record of historical practice, not a dosage recommendation - the figures are what the sources say, not what HerbMate tells you to take. Amounts, potency, and safe use vary enormously by preparation, plant part, and person.

A comprehensive systematic review of data from spontaneous adverse event reporting schemes and published clinical studies, post-marketing surveillance studies, surveys and case reports was carried out in September 2004 to investigate the safety of agnus castus extracts. No drug interactions were identified. Agnus castus extracts used in the data reviewed included Agnolyt, Agnucaston, Strotan and ZE 440. However, agnus castus has dopamine agonist properties, and may therefore interact with drugs with either dopamine agonist or dopamine antagonist actions. Agnus castus contains oestrogenic compounds but it is unclear whether the effects of these compounds are additive, or antagonistic, to oestrogens and oestrogen antagonists (e.g. tamoxifen). Although agnus castus binds with opioid receptors, no serious interaction with opioid analgesics would be expected.

Opioids

The interaction between agnus castus and opioids is based on experimental evidence only.

Oestrogens or oestrogen antagonists

Agnus castus contains oestrogenic compounds. This may result in additive effects with oestrogens or it may oppose the effects of oestrogens. Similarly, agnus castus may have additive effects with oestrogen antagonists or oppose the effects of oestrogen antagonists (e.g. tamoxifen). A 32-year-old woman took a herbal medicine made from agnus castus, on her own initiative, before and in the early follicular phase of her fourth cycle of unstimulated IVF (in vitro fertilisation) treatment in order to try to promote ovarian function. In this cycle, she developed four follicles, and her serum gonadotrophin and ovarian hormone measurements became disordered. The agnus castus was stopped and she experienced symptoms suggestive of mild ovarian hyperstimulation syndrome in the luteal phase. Two subsequent cycles were endocrinologically normal with single follicles, as were the three cycles before she took the herbal preparation. It has also been suggested that agnus castus may provide relief from menopausal symptoms.

Food

No interactions found.

Medicine

No interactions found.

Dopamine agonists or antagonists

Agnus castus has dopamine agonist properties, and may therefore interact with drugs with either dopamine agonist or dopamine antagonist actions. In a double-blind study in women suffering from mastalgia, agnus castus extracts reduced serum prolactin levels (by about 4 nanograms/mL compared with about 0.6 nanograms/mL for placebo). The agnus castus extracts used in this study were an oral solution, Mastodynon, and a tablet, MA 1025 E1.

These entries keep the wording of the reference they come from, and three phrases mean three different things. "No interactions found" means the source looked for reports of that pairing and found none. "No data found" means nothing has been published either way. "Based on experimental evidence only" means the effect has been seen in a laboratory or animal study but not in people - a reason for caution, not a report of harm.