Which herbs are unsafe during breastfeeding? The answer isn't always straightforward because some herbs have documented concerns, while others haven't been studied well enough in nursing mothers. Herbal products can also vary greatly in strength, purity, and preparation, so something described as natural isn't automatically suitable during lactation.
Which Herbs Are Unsafe During Breastfeeding or Require Extra Caution?
Some herbs deserve particular caution because their active compounds may affect the mother, the infant, or milk production. In other cases, experts recommend avoiding an herb because researchers don't have enough evidence to establish its safety.
That distinction matters. A lack of evidence doesn't prove that an herb is harmful. However, breastfeeding exposes another person, often a very young infant, so uncertainty carries more weight.
Herbs That May Pose Risks to a Breastfed Baby
Goldenseal is one of the clearer examples. LactMed reports that most sources recommend avoiding neonatal exposure to goldenseal, including exposure through breastfeeding. Reliable information about its transfer into human milk is also lacking.
Ashwagandha also requires caution. There isn't enough published information about its effects on nursing infants or its presence in breast milk. This uncertainty becomes especially relevant when feeding newborn or premature babies.
Feverfew presents a similar problem. Reliable lactation safety information is limited, and some reviewers recommend avoiding it while breastfeeding for that reason.
Medicinal quantities of oregano are another example of why context matters. Oregano used normally to season food isn't the same exposure as concentrated oregano oil or supplements. LactMed notes that oregano is generally recognized as safe as a food ingredient, yet recommends avoiding amounts greater than normal food use during breastfeeding because adequate safety data are lacking.
Herbs That May Reduce Breast Milk Supply
Some herbs attract attention not because they're toxic to babies, but because they may affect milk production.
Sage has traditionally been used to reduce lactation, including during weaning or excessive milk production. However, scientific studies confirming this effect haven't been found. That means mothers shouldn't assume one cup of sage tea will suddenly stop milk production, but concentrated or frequent use deserves more caution.
Peppermint has also traditionally been used to suppress milk production. Laboratory and animal research has demonstrated this effect at high doses, although that doesn't establish the same effect from ordinary dietary consumption in breastfeeding women. Small amounts of some peppermint components can enter breast milk.
Parsley is sometimes included in products intended to decrease milk flow, but good clinical evidence is lacking. Normal quantities used in meals shouldn't automatically be treated like medicinal capsules or concentrated preparations.
How Herbal Remedies Can Affect Breastfeeding Mothers and Babies
Herbs contain biologically active substances. Once swallowed, some compounds can enter the bloodstream and potentially reach breast milk.
Whether that exposure matters depends on several factors. The mother's dose, frequency of use, preparation, metabolism, and the baby's age can all influence risk. A healthy older infant may also handle an exposure differently from a premature newborn.
Can Herbal Ingredients Pass Into Breast Milk?
Yes, some herbal compounds can pass into breast milk.
For example, small quantities of menthol and another peppermint component have been detected in human milk. Research involving dill has also detected small amounts of one of its components in milk.
However, researchers haven't measured breast milk transfer for every medicinal plant. This missing information is one reason healthcare professionals may recommend caution even when no harmful event has been documented.
The form of the herb matters too. Eating fresh mint with dinner isn't equivalent to taking concentrated peppermint extract several times daily.
Possible Side Effects in Breastfed Babies
Potential reactions depend on the herb and the amount consumed. Parents should pay attention to unexpected changes after starting a new herbal remedy.
Changes in feeding, unusual sleepiness, digestive upset, vomiting, skin reactions, or marked irritability deserve attention, particularly if they begin soon after introducing a supplement.
Newborns require greater care because their liver and kidneys are still developing. Premature babies and infants with medical conditions may also have less ability to process certain substances.
Parents who notice significant symptoms should seek medical advice rather than trying to identify the responsible ingredient themselves.
Popular Herbal Remedies and Supplements During Breastfeeding
Herbal products are often marketed for sleep, stress, digestion, immunity and milk production. Their popularity can create the impression that they've been thoroughly tested during lactation.
Often, they haven't.
The NHS advises breastfeeding mothers to seek professional advice about herbal remedies because there isn't enough information to guarantee their safety.
Are Herbal Teas Safe While Breastfeeding?
Safety depends heavily on the ingredients, quantity and frequency.
A cup of tea containing a familiar culinary herb may provide a relatively modest exposure. A strongly brewed medicinal tea consumed several times daily can be very different.
Mixed teas create another challenge. A product marketed as a calming or nursing tea may contain several herbs, making it difficult to assess each ingredient separately.
The label therefore matters more than the marketing description. Mothers should check every herb rather than assuming that words such as organic, traditional, or breastfeeding tea indicate proven safety.
Are Herbal Supplements and Lactation Products Safe?
Products designed to increase milk supply deserve similar scrutiny. They may contain fenugreek, milk thistle, moringa, fennel, or several herbs combined.
Evidence varies significantly.
For example, LactMed's 2026 review of milk thistle says scientifically valid clinical trials don't support milk thistle itself as a galactagogue. However, limited information suggests its major components aren't present in breast milk at measurable levels.
Evidence for moringa has developed further. A July 2026 LactMed review reports that a recent meta-analysis found increased prolactin and milk volume and quality across available studies. However, long-term benefits for breastfed infants remain insufficiently studied.
Milk supply supplements also shouldn't replace investigation of the reason supply appears low. Feeding frequency, positioning, milk transfer and underlying health issues may need attention first.
Why Natural Doesn't Always Mean Safe During Breastfeeding
Plants produce chemicals capable of affecting the human body. That's precisely why many herbal remedies have medicinal uses.
The more useful question isn't whether something is natural. It's how much is being consumed, which compounds it contains, and what reliable evidence says about lactation.
Dosage, Herbal Extracts, Tinctures and Essential Oils Matter
Concentration can completely change the safety discussion.
An herb eaten as part of a normal meal may provide a small amount of active compounds. Capsules, tinctures, and extracts can provide considerably more. Essential oils are especially concentrated and shouldn't be treated as interchangeable with the original plant.
Preparation methods can also alter the quantities and proportions of active compounds. LactMed notes that extraction and formulation methods vary among herbal products.
This explains why advice about culinary use doesn't necessarily apply to medicinal doses.
Supplement Quality, Contamination and Medication Interactions
The ingredient itself isn't the only concern.
LactMed notes that dietary supplements don't have to undergo breastfeeding safety and effectiveness testing before reaching consumers. Commercial products can also differ in composition, while formulations may change over time.
Contamination adds another concern. Herbal products can contain heavy metals originating from soil, while manufacturers also need to control bacterial and fungal contamination.
Interactions matter too. Herbal compounds can influence how medicines work. A breastfeeding mother taking prescription medication should therefore tell her doctor or pharmacist about supplements and herbal remedies she uses.
How to Use Herbs More Safely While Breastfeeding
Breastfeeding doesn't mean every herb must disappear from the kitchen. It does mean medicinal use deserves more scrutiny than ordinary food use.
The safest approach considers the exact herb, preparation, dose, mother's health, and baby's age rather than relying on broad claims about natural remedies.
How to Check Whether an Herb Is Breastfeeding Safe
Start with the scientific name where possible. Common names can describe different plants, while combination supplements may contain ingredients that aren't obvious from the product name.
Reliable lactation references such as LactMed can help distinguish established concerns from areas where evidence doesn't exist.
A pharmacist, doctor, midwife or qualified lactation professional can also assess the herb alongside medications and individual health circumstances.
What If You've Already Taken a Questionable Herb?
Taking an herb once doesn't automatically mean breastfeeding must stop. Risk depends on the substance, amount, preparation, timing, and infant.
Write down the product name, ingredients, dose, and time taken. Keep the packaging if possible. A healthcare professional can use those details to assess the exposure more accurately.
Avoid abruptly stopping breastfeeding based solely on something read online. Professional advice can establish whether any action is necessary.
Conclusion
So, which herbs are unsafe during breastfeeding? Goldenseal and several poorly studied medicinal herbs warrant significant caution, while herbs such as sage and peppermint may raise separate concerns about milk production when used in concentrated amounts. The larger issue is that many herbal products lack strong lactation research.
Food use, medicinal doses, extracts, and essential oils shouldn't be treated as equivalent. Checking the exact ingredient and concentration gives parents a far more useful picture of risk. If there's uncertainty, professional lactation or medical advice remains the safest way to protect both mother and baby.
