Pregnancy is so precious, and we all wait for that beautiful moment when a new life begins to grow within. It’s a time filled with anticipation, joy, and a deep desire to protect and nourish the little one developing inside. During this transformative period, a mother’s health becomes paramount, not only for her well-being but also for the baby’s safe development.
With countless supplements and herbs available on the market, many women wonder which ones are safe and which should be strictly avoided. While natural remedies are often perceived as gentle or harmless, certain herbs and dietary supplements can be surprisingly potent — and dangerous — during pregnancy. Understanding which substances to avoid is essential in supporting a safe and healthy pregnancy journey.
That’s why we’ve gathered this comprehensive guide to help you make informed decisions. Let’s explore herbs and supplements that should be avoided during pregnancy.
Why Some Herbs and Supplements Are Harmful in Pregnancy
Herbs and supplements are concentrated forms of plant compounds and nutrients, and not all of them are tested for safety in pregnant women. Because of these risks, many healthcare providers recommend avoiding specific herbs and supplements entirely, while others may be used in very limited quantities or only under medical supervision.
The concern arises when these substances:
- Stimulate uterine contractions, which increase the risk of miscarriage or premature labor.
- Cross the placenta and affect fetal development.
- Causes liver or kidney toxicity.
- Interfere with hormone levels or blood flow to the uterus.
Herbs That May Induce Uterine Contractions or Are Abortifacient
Some herbs contain active compounds that can stimulate the uterus and are known to be abortifacient — substances that may induce abortion. These herbs should be avoided throughout pregnancy, especially in the first and second trimesters when the risk of miscarriage is highest.
- Quinine: Quinine is a medicine for malaria. Doctors sometimes use it during pregnancy, but only when they must. Quinine can make the uterus contract. This may cause early labor or miscarriage. Taking too much quinine can harm the baby. It may cause stillbirth, birth defects, or hearing problems. Quinine can also lower the mother’s blood sugar. This can make her feel weak or dizzy. Pregnant women should not take quinine for leg cramps or other simple reasons. A doctor should always decide if it is safe to use. You can also find quinine in many drinks such as tonic water. Tonic water is very popular for its unique bitter taste. The federal institute for risk assessment in Germany stated that pregnant women should treat drinks with quinine in them as a medicinal product and avoid them during pregnancy for safety of the unborn baby. Even if the amount of quinine in a drink is a small amount still avoid it.
- Wormseed (Epazote, Paico): Wormseed contains ascaridole, a compound that may cause uterine contractions and has neurotoxic effects. Although it has traditional uses in parasitic infections, it is not safe during pregnancy due to its toxic profile.
- Fennel: Often used for digestive health, fennel in high doses may stimulate the uterus. While small amounts of food are likely safe, concentrated extracts and teas should be avoided during pregnancy.
- Devil’s Claw: Primarily used for pain relief and inflammation, Devil’s Claw may stimulate uterine contractions and is not considered safe for pregnant women, especially during the early stages.
- Hops: Though commonly used in teas to aid sleep or reduce anxiety, hops may have uterine stimulant properties. It is best avoided throughout pregnancy.
- Motherwort: Traditionally used for heart health and anxiety, motherwort can cause uterine stimulation, posing a miscarriage risk in the early months.
- Bugleweed: Bugleweed, often used for thyroid disorders, may affect hormone levels and stimulate uterine activity, making it unsafe during pregnancy.
- German Chamomile: While often consumed in tea form, German chamomile in high doses can lead to uterine contractions. Occasional, small amounts may be safe, but large or frequent doses are discouraged.
- Pennyroyal: Both the herb and the essential oil of pennyroyal are highly toxic during pregnancy. The oil, in particular, is a potent abortifacient and has been linked to liver toxicity and death.
- Zoapatle: Used traditionally in some cultures to induce labor or abortion, zoapatle is considered highly unsafe during pregnancy due to its uterine stimulant effects.
- Blue Cohosh: This herb is sometimes used to stimulate labor, but it is teratogenic and toxic to the fetus. It can cause heart issues in the baby and complications during delivery.
- Black Cohosh: Black cohosh is known to cause uterine contractions and potential liver damage. Though sometimes used to prepare the cervix for labor, it should never be taken without direct medical supervision.
- Dong Quai (Chinese Angelica): A popular herb in traditional Chinese medicine, dong quai can stimulate uterine contractions and significantly raise the risk of miscarriage, especially in early pregnancy.
- Yohimbe: Used historically as an aphrodisiac, yohimbe is associated with high blood pressure, heart attacks, and seizures. It is completely unsafe during pregnancy.
- Feverfew: Known for its use in preventing migraines, feverfew has uterine stimulant properties. It is not safe for pregnant women and should be avoided.
- Goldenseal: Goldenseal contains berberine, which can cross the placenta and contribute to jaundice and potential brain damage in newborns.
- Saw Palmetto: Primarily used for prostate health, saw palmetto has hormonal effects that may interfere with pregnancy and should be avoided in oral form. Tansy, Red Clover, Angelica, Yarrow, Wormwood, Ephedra, Mugwort. These herbs are generally regarded as unsafe for pregnant women due to either their stimulant, hormonal, or toxic effects.
- Arnica: Used topically for bruises and inflammation, arnica is dangerous when taken orally. It has uterine stimulant and abortifacient properties.
- Other Herbs to Avoid: Many herbs have laxative, hormonal, or stimulant effects that are dangerous during pregnancy. The following herbs either lack sufficient safety data or are known to pose serious health risks during pregnancy:
- Beth Root
- Cascara Sagrada
- Chaste Tree Berry
- Cinchona
- Cotton Root Bark
- Juniper
- Kava Kava
- Licorice Root
- Meadow Saffron
- Poke Root
- Rue
- Sage (in high amounts)
- John’s Wort
- Senna
- Slippery Elm Root
- White Peony
- Yellow Dock
Supplements to Avoid or Use With Caution
Even some common dietary supplements may not be safe during pregnancy, especially in high doses or improper forms.
- Ginseng: Ginseng gives energy and helps with stress. Many people use it to feel better. But pregnant women should not take ginseng. It may cause birth defects in animals. It also makes the blood thinner, which can cause more bleeding. Ginseng may change sugar levels in the blood. This can lead to dizziness or feeling sick. It may also cause trouble with sleep or mood. Ginseng is not safe during pregnancy, especially in the first few months.
- Ginkgo Biloba: Ginkgo Biloba helps with memory and blood flow. But it can make the blood too thin. This may cause bleeding during birth. Some people believe ginkgo makes periods start. That may lead to a miscarriage in early pregnancy. There is not enough research to know if it is safe. One component of ginkgo biloba was found in the placenta of women who have consumed ginkgo biloba supplements according to researchers at Wayne state university in Detroit. That component is an alkaloid called colchicine which can be fatal if consumed in high doses. It has anti-inflammatory effects. Some research has discovered that colchicine can harm a developing fetus. When taking ginkgo supplements regularly during pregnancy colchicine can build up in the womb. The study only focused on colchicine in the womb. It is better not to use ginkgo during pregnancy.
- High Doses of Preformed Vitamin A (Retinol): Vitamin A is essential for fetal development, but in the form of retinol (found in animal sources like liver and many supplements), excessive intake can cause birth defects, particularly affecting the brain, heart, and spinal cord.
- Melatonin: Melatonin is a hormone used to regulate sleep, but it may interfere with hormonal balance and affect fetal development. Its safety during pregnancy has not been well established.
- John’s Wort: This popular supplement for depression can cause uterine contractions, interact with medications, and affect fetal development, making it unsafe during pregnancy.
Herbs to Use Only With Caution
Not all herbs are outright dangerous, but some should be used only occasionally or under a healthcare provider’s supervision.
- Chamomile: While small amounts of chamomile tea may be calming and helpful for digestion, frequent or large doses can act as a uterine stimulant. It’s best to keep consumption moderate and infrequent.
- Echinacea: Used for immune support, Echinacea has limited safety data in pregnancy. Some studies suggest it’s likely safe, but more research is needed. Caution is advised, especially during the first trimester.
- Evening Primrose Oil: Evening primrose oil is sometimes used to help ripen the cervix before labor. However, it should never be taken unless under medical guidance, as it may induce labor or cause complications.
- Passion Flower: Known for its calming properties, passion flower may stimulate the uterus and should not be consumed orally in supplement or tea form during pregnancy.
- Peppermint: Generally safe in food-level amounts, peppermint may help with nausea or digestion. However, excessive intake (especially concentrated oils or capsules) could be unsafe.
- Pumpkin Seed: Pumpkin seeds are safe as a food source, rich in nutrients like magnesium and zinc. However, extremely high doses in supplement form may have unknown or toxic effects.
Final Words
Pregnancy is a time when the body becomes more sensitive and vulnerable to external influences, including natural compounds. While the placenta does act as a protective barrier, many substances — including herbs and supplements — can still pass through to the developing fetus. And some of these natural substances can be surprisingly potent.
That’s why it’s so important for pregnant women to stay fully aware and make thoughtful, informed choices at every step. Just because something is labeled “natural” doesn’t automatically mean it’s safe, especially during pregnancy.
So be cautious, stay curious, and always check with a trusted healthcare provider before taking anything new.
