Herbs to Use Cautiously in Pregnancy & Nursing

Essential awareness for anyone who is pregnant, nursing, or sharing herbal knowledge with others

Important note before you read:
This article provides educational awareness, not medical advice. Pregnancy and nursing are times when professional guidance matters more than usual. If you are pregnant or nursing and want to use herbs, please discuss with your midwife, OB, or healthcare provider. If you are supporting someone who is pregnant or nursing, encourage them to check with their provider before adding any herbs to their routine — even ones commonly considered safe.

Pregnancy and nursing are among the most important contexts in herbal practice to approach with extra care. Not because herbs are dangerous — plants have supported pregnant and nursing people throughout human history, and many herbs are entirely appropriate and even deeply nourishing during these times. But because the stakes are higher, the physiology is different, and some herbs that are completely safe for a non-pregnant adult have real potential to cause harm during pregnancy or affect a nursing infant.

This article is not meant to frighten you or anyone you share herbal knowledge with. It’s meant to give you a clear, practical foundation so you know which herbs warrant extra thought, which ones are widely considered safe, and when to defer to a healthcare provider rather than proceeding on your own.

Even if you are not pregnant or nursing yourself, this knowledge matters. As someone learning herbalism, you will inevitably share what you know — with friends, family members, and community. Some of those people will be pregnant or nursing, and they may not think to mention it. Knowing this topic well is part of being a trustworthy and careful herbalist.

Why Pregnancy Changes the Conversation

Several things make herbal safety during pregnancy meaningfully different from herbal safety at other times.

The uterus is sensitive to certain herbal stimulation

Some herbs have what herbalists call emmenagogue or uterine stimulant actions — meaning they promote blood flow to the uterus or stimulate uterine contractions. In a non-pregnant person, these herbs may be used intentionally to support a delayed menstrual cycle or ease menstrual cramps. In pregnancy, particularly in the first trimester, that same action is deeply contraindicated — it can trigger miscarriage.

This is the most important category to understand. The herbs with the strongest uterine stimulant actions are not subtle in their effects, and a number of them are plants that beginners may encounter in herbal literature without immediately recognizing the pregnancy concern.

The developing fetus cannot metabolize substances the way an adult can

What passes through the placenta reaches a developing system that is not yet capable of processing and clearing it the way an adult body would. Some compounds that are handled easily by adult physiology can accumulate in fetal tissue or interfere with development. This is why the first trimester — when organ systems are forming — is the period of highest concern, though caution is appropriate throughout pregnancy.

Herbs can pass into breast milk

During nursing, herbs consumed by the mother can pass into breast milk in varying amounts and reach the infant. Infants — especially newborns — have immature liver and kidney function and cannot clear substances as efficiently as adults. Herbs that are safe for an adult may not be safe for a newborn or young infant via breast milk.

On the positive side, this also means that gentle, well-tolerated herbs consumed by a nursing mother can sometimes benefit the infant as well — a calm chamomile tea for a stressed mother may reach a colicky baby in small amounts and help both of them. This is part of why herbs have been used in nursing cultures across history. But it’s a reminder that nursing is not a neutral state where herbs have no effect.

Individual variation and trimester matter

Not all trimesters carry the same level of concern. The first trimester is generally the most sensitive period for most concerns. Some herbs that are contraindicated in early pregnancy are considered acceptable in late pregnancy, and in some cases are specifically used to prepare for labor. The tables below note trimester-specific considerations where they are relevant.

Herbs to Avoid or Use Cautiously During Pregnancy

The table below covers the herbs most commonly encountered in beginner herbal practice that have meaningful pregnancy concerns. It is not exhaustive — for any herb you’re unsure about, check the individual monograph in this library and consult a healthcare provider.

Herb	Safety level	Notes
Blue cohosh	Avoid entirely	Uterine stimulant and potential fetal toxin; associated with serious adverse outcomes; avoid throughout pregnancy
Pennyroyal	Avoid entirely	Strongly emmenagogue and abortifacient; toxic at doses that affect the uterus; avoid all forms including essential oil
Tansy	Avoid entirely	Historically used to induce abortion; toxic; no safe therapeutic use in pregnancy
Mugwort	Avoid entirely	Uterine stimulant; traditional emmenagogue; avoid internally throughout pregnancy
Black cohosh	Avoid — except near term under guidance	Uterine stimulant; traditionally used to prepare for labor but only appropriate near term under professional guidance
Dong quai	Avoid entirely	Uterine stimulant; blood-moving herb; avoid throughout pregnancy
Goldenseal	Avoid entirely	Uterine stimulant; berberine has documented concerns for fetal development; avoid throughout
Berberine-containing herbs	Avoid entirely	Includes goldenseal, barberry, Oregon grape; berberine has fetal safety concerns
Licorice root (high doses)	Avoid high doses	Culinary use generally fine; high therapeutic doses associated with preterm labor in some research; use cautiously
St. John’s Wort	Use cautiously	Insufficient safety data; some concerns; consult healthcare provider before use
Echinacea	Probably fine; check with provider	Most evidence suggests short-term use is safe; some practitioners advise caution in first trimester; worth checking
Ginger	Generally considered safe	Well-studied for nausea in pregnancy; culinary and moderate therapeutic doses considered safe; avoid very high doses
Red raspberry leaf	Second/third trimester only	Traditionally used to tone the uterus in late pregnancy; avoid in first trimester; widely used in second and third trimester under traditional guidance
Chamomile	Moderate use generally fine	Regular culinary-strength use considered safe by most sources; very high doses theoretically emmenagogue — reasonable moderation is sensible
Peppermint	Generally considered safe	Widely used and generally considered safe in normal amounts; avoid concentrated essential oil internally

About this table: Safety ratings in herbal practice reflect traditional knowledge, available research (which is often limited), and professional clinical judgment. They are not identical across all sources. When in doubt about any herb not listed here, the safest approach is to check the monograph, consult a reliable reference, and when in doubt, leave it out.

Herbs to Avoid or Use Cautiously During Nursing

The nursing period has somewhat different concerns than pregnancy. The primary questions are whether an herb passes into breast milk, whether it is safe for an infant at the levels that might be present in milk, and whether it affects milk supply.

Herb	Safety level	Notes
Pennyroyal	Avoid entirely	Toxic; passes into breast milk; avoid all forms
Sage (large doses)	Avoid if nursing	Traditional use to dry up milk; large doses can significantly reduce milk supply; culinary amounts fine
Peppermint (large doses)	Use cautiously	High doses may reduce milk supply in some women; normal amounts in food and occasional tea generally considered fine
St. John’s Wort	Use cautiously	Some evidence it passes into breast milk; limited safety data; consult provider
Kava	Avoid	Passes into breast milk; sedative and liver concerns; avoid during nursing
Fenugreek	Often used to increase milk supply	Widely used as a galactagogue; generally considered safe; some infants may experience digestive upset
Blessed thistle	Often used to support milk supply	Traditional galactagogue; generally considered safe during nursing
Chamomile	Generally considered safe	Reasonable amounts in tea considered safe during nursing; passes mildly into milk and may help a colicky infant
Echinacea	Probably fine; limited data	Short-term use generally considered low risk; limited specific nursing safety data available

Herbs Generally Considered Nourishing and Safe

It would be a disservice to leave this article focused only on what to avoid. Herbal medicine has a long and meaningful tradition of supporting pregnancy and the postpartum period, and there are many gentle, nourishing herbs with excellent safety records during these times.

The following herbs are widely considered safe and are commonly used to support the specific needs of pregnancy and nursing. As always, reasonable moderation is sensible, and checking with a midwife or healthcare provider is always worthwhile:

Oat straw (Avena sativa) — Deeply nourishing to the nervous system; calming without being sedating; rich in minerals; widely regarded as one of the safest pregnancy tonics
Nettle leaf (Urtica dioica) — Extraordinarily nutrient-dense; high in iron, calcium, magnesium, and vitamins; traditional pregnancy tonic; supports kidney function; often used as an infusion throughout pregnancy
Red raspberry leaf (Rubus idaeus) — Traditional uterine tonic; used in second and third trimester to support uterine tone in preparation for labor; avoid in first trimester
Ginger (Zingiber officinale) — Well-studied for nausea in early pregnancy; generally considered safe at culinary and moderate therapeutic doses
Chamomile (Matricaria chamomilla) — Gentle nervine and digestive support; moderate use in tea generally considered safe; widely used to ease digestive discomfort in pregnancy
Lemon balm (Melissa officinalis) — Gentle calming herb; generally considered safe during pregnancy in reasonable amounts; helpful for anxiety and digestive nervousness
Peppermint (Mentha piperita) — Helpful for nausea and digestive discomfort; generally considered safe at normal tea amounts; avoid concentrated essential oil internally
Fenugreek (Trigonella foenum-graecum) — Traditional galactagogue for nursing; widely used to support and increase milk supply
Blessed thistle (Cnicus benedictus) — Traditional nursing herb; used alongside fenugreek to support milk supply; generally considered safe during nursing

A Special Note on Essential Oils

Essential oils deserve separate mention because they are highly concentrated plant extracts — far more potent by volume than teas, tinctures, or even capsules. Many essential oils that are considered safe for general topical or aromatic use are contraindicated during pregnancy.

The oils most commonly flagged during pregnancy include pennyroyal, mugwort, tansy, clary sage, rosemary (at high concentrations), and a number of others. Even oils that are not specifically contraindicated should be used more cautiously during pregnancy than at other times — diluted more thoroughly, used less frequently, and always with good ventilation.

If you are pregnant or supporting someone who is:
Be especially careful with essential oils. The concentration of plant compounds in an essential oil is dramatically higher than in a tea or tincture. Oils that are safe for general use may not be safe in pregnancy. When in doubt, avoid internal use of essential oils entirely during pregnancy and stick to very diluted topical or aromatic use of only well-established safe oils.
If you use essential oils in your practice, consult a qualified aromatherapist or your healthcare provider for pregnancy-specific guidance.

A Note on Herbal Teas Sold in Grocery Stores

A question that often comes up for pregnant and nursing people is whether the herbal teas sold in regular grocery stores are safe. The answer is generally yes for teas specifically formulated and labeled for pregnancy — these are typically made with very gentle herbs at mild concentrations. Standard single-herb teas like peppermint, ginger, and chamomile at normal tea-brewing strength are generally considered safe.

The concern arises with some herb teas that contain ingredients not appropriate during pregnancy — licorice root, for example, appears in many commercial tea blends and is considered fine in small amounts but worth noting. “Detox” or “cleanse” teas often contain stimulant laxative herbs like senna that are not appropriate during pregnancy.

The habit of reading ingredient labels — on tea bags, supplements, and any herbal product — is one of the most practical safety habits a pregnant or nursing person can develop.

When to Defer and When to Reassure

As someone sharing herbal knowledge, you’ll encounter moments where a pregnant or nursing person asks you about an herb and you need to decide how to respond. Here is a practical framework:

A simple framework for pregnancy and nursing herb questions:

If someone is pregnant or nursing and asks about an herb on the avoid list — be clear and direct: this one isn’t appropriate right now.

If they’re asking about a gentle nourishing herb with a good safety record — you can share what you know while encouraging them to confirm with their midwife or provider.

If you’re not sure — say so honestly and suggest they check with their healthcare provider. “I’m not certain about that one during pregnancy — it’s worth asking your midwife” is a completely appropriate and trustworthy answer.

When in doubt, leave it out. This is always the right default in pregnancy.

The instinct to be helpful can sometimes lead to reassuring someone when more caution is actually warranted. In pregnancy particularly, erring on the side of caution is not overcautious — it’s appropriate. A pregnant person who skips an herb they didn’t actually need loses nothing. The reverse is not always true.

Keeping This in Perspective

Plants and pregnancy have coexisted throughout human history, and herbal traditions around pregnancy and birth are among the most developed and carefully observed in the whole of herbal medicine. There is a rich, meaningful body of traditional knowledge about which herbs nourish, support, and protect during these times.

The goal of this article is not to make pregnancy feel like a minefield where herbs are best avoided entirely. It’s to give you the specific awareness you need to navigate this topic with both confidence and care — knowing which herbs genuinely warrant caution, which ones have an excellent safety record, and when to bring a healthcare provider into the conversation.

Midwives in particular tend to be knowledgeable about herbs and are often the most appropriate professional resource for pregnancy herb questions. If someone you’re sharing knowledge with is pregnant or planning to become pregnant, encouraging them to talk with their midwife or OB about herbal use is one of the most genuinely helpful things you can do.

The herbs to avoid in pregnancy are a small, well-identified group.
The herbs that nourish and support pregnancy are many.
Know the difference. When in doubt, leave it out.
And always encourage pregnant and nursing people
to work with their healthcare provider.

Want to Go Deeper with Herbal Medicine?

Start with the free 40-Page Herbal Foundations Starter Guide.

It’s packed with foundational herbal knowledge to help you begin learning practical herbalism at your own pace.

👉 Enter your email below and we’ll send it right over.

🌿 Disclaimer 🌿

The information provided on this website is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease.

Herbal remedies can affect individuals differently and may interact with medications or medical conditions. Always consult a qualified healthcare professional before beginning any new herbal regimen, especially if you are pregnant, nursing, taking medications, or have a medical condition.

Southwestern Herbal Academy does not provide medical advice, diagnosis, or treatment.