Chasteberry in pregnancy and breastfeeding

What NCCIH says about safety

Chasteberry is generally well tolerated in the short term. Chasteberry fruit extract has been used safely in research studies for up to 3 months. Side effects are generally mild and may include nausea, stomach pain, diarrhea, headache, or itching. Chasteberry supplementation may not be safe for women with hormone-sensitive conditions, such as breast, uterine, or ovarian cancer. The use of chasteberry during pregnancy or while breastfeeding may be unsafe.

Quoted in full from NCCIH so nothing is lost in summarising. Where they say “little is known”, that means the studies do not exist — not that the herb is known to be safe, and not that it is known to be harmful.

How much is actually known

Several studies of low-to-moderate quality in people have evaluated chasteberry for alleviating PMS symptoms such as breast pain or tenderness. There isn’t a lot of strong research on the effectiveness of chasteberry for other conditions. Much research has been conducted on the safety of this herb and has determined that chasteberry supplementation may not be safe for women with hormone-sensitive conditions, such as breast, uterine, or ovarian cancer. Some preclinical evidence states that the use of chasteberry during pregnancy or while breastfeeding may be unsafe.

What the research has found

Some research has suggested that chasteberry might reduce PMS symptoms such as breast pain or tenderness, but higher-quality evidence is needed to reach any definitive conclusions. One study suggested that chasteberry might reduce heavy menstrual bleeding related to an intrauterine device (IUD), but the evidence is of low quality. There isn’t enough reliable evidence to know if chasteberry would help with sexual dysfunction or infertility (but chasteberry may be unsafe during pregnancy). A preliminary study suggested that chasteberry might help with some menopausal symptoms, but more research is needed to study this potential effect. Initial reports have suggested that some chasteberry extracts might have antifungal effects, but more research is needed to explore this potential in people.

Before you take this

Dose and form change the answer completely. A culinary amount of a spice, a cup of tea, and a concentrated supplement extract are three different things, and most research is done on the last of them.

Supplements are also not regulated like medicines, so strength and purity vary between products. Bring the actual bottle to your midwife, doctor or pharmacist — that conversation is worth more than any page, including this one.