European Mistletoe in pregnancy and breastfeeding

What NCCIH says about safety

European mistletoe berries and leaves can cause serious harmful effects when taken orally. Injected European mistletoe extract may cause soreness and inflammation at the injection site, headache, fever, and chills. A few severe allergic reactions have been reported. If you take any type of medicine, talk with your health care provider before using European mistletoe or other herbal products; some herbs and medicines interact in harmful ways. European mistletoe is probably unsafe for use during pregnancy. Little is known about whether it’s safe for use while breastfeeding.

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

Although European mistletoe has been studied as a treatment for cancer, its effects are not well understood because much of the research has been of poor quality. Most studies have evaluated European mistletoe administered through injection by a health care provider. Very little research has looked at European mistletoe taken orally.

What the research has found

European mistletoe is not a proven cancer treatment. It should not be used as a treatment for cancer outside of clinical trials (studies in people). There have been clinical trials of European mistletoe for cancer treatment, mostly in Europe. Although some trials indicated that European mistletoe improved survival or quality of life, many of the trials had major weaknesses that raise doubts about their findings. These weaknesses have included small numbers of patients, lack of information about the patients, lack of information about the dose of European mistletoe, and problems with the design of the studies. The National Center for Complementary and Integrative Health and the National Cancer Institute performed a preliminary trial to evaluate the safety of injected European mistletoe extract in combination with a cancer drug in patients with advanced cancer. It showed that patients could tolerate the herb/drug combination.

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.