Using Fennel While Breastfeeding

Information, Uses, Warnings, and Side Effects


Alexandra Shytsman 

Fennel (Foeniculum vulgare) is a common herb that's been used for cooking and medicinal purposes since the times of ancient Egypt. One of fennel's most popular uses is to stimulate and increase the production of milk for breastfeeding. Like any herbal supplement or medication, fennel comes with potential benefits and side effects. We'll explore the safety and effectiveness of fennel on breast milk supply

Ways to Take Fennel

Fennel may be brewed as a tea, consumed as a vegetable, or used as a spice to flavor meals. Here are some of the ways breastfeeding mothers might choose to take fennel:

  • Capsules: Fennel supplements are available in supermarkets, pharmacies, vitamin stores, and online.
  • Herb/spice: Fennel seeds add flavor to many recipes, including fish, salads, and sauces.
  • Seeds: Fennel seeds can be chewed whole and raw or roasted.
  • Vegetable: The vegetable part of the fennel plant can be eaten raw or cooked. You can easily add it to soups or other dishes.

How to Make Fennel Tea

To make fennel tea, place 8 ounces (1 cup) of boiling water in a mug with 1 to 3 teaspoons of fennel seed. Let it sit for approximately 10 minutes then strain the seeds from the tea and enjoy. If you have them, freshly crushed fennel seeds are preferred.

Many commercially prepared lactation supplements and nursing teas contain fennel in combination with other breastfeeding herbs, such as fenugreek, alfalfa, stinging nettle, and blessed thistle.

Does Fennel Increase Milk Supply?

Women have been using fennel to make more breast milk for centuries. Fennel is believed to be a galactagogue, or a substance that increases breast milk. Fennel's reputation for enhancing breast milk is related to its natural estrogen-like properties.

However, there is little quality data to support an official recommendation of fennel for breastfeeding. Some small studies suggest that fennel may increase levels of prolactin, the main hormone responsible for stimulating milk production, and it might increase milk volume and infant weight gain. But evidence is mixed about its benefits.

While fennel alone is unlikely to be effective enough to overcome major barriers to breastfeeding, it might help boost your supply.

Other Benefits and Uses

Besides promoting milk production and stimulating the flow of breast milk for breastfeeding moms, other purported uses of fennel include:

  • Flavor foods and medications
  • Freshen breath
  • Increase libido
  • Increase metabolism, suppress hunger, and aid in weight loss
  • Lower blood sugar levels in people with diabetes
  • Pass through breast milk to help a baby’s digestion and relieve the symptoms of colic
  • Promote healthy digestion
  • Relieve menstrual problems and balance the menstrual cycle
  • Soothe coughs and sore throats
  • Thin mucus and loosen chest congestion
  • Treat stomach upset and gas

Fennel Safety Considerations

Although fennel does transfer into breast milk, it is generally considered safe to use while you are breastfeeding. The safest way to take fennel is through food or an herbal tea. Avoid taking large amounts or concentrated doses of fennel or any other herbal supplements to reduce the risk of unwanted side effects.

To stay on the safe side, it's best to avoid medicinal herbs, like fennel, during pregnancy. The small amount of fennel found in foods such as Italian sausage or bread is not likely to be harmful, but extra supplementation should be reserved until after giving birth.

Warnings and Side Effects

Herbal remedies have been used as medical treatments for thousands of years. However, even though herbs like fennel are natural, they can be very potent and potentially dangerous.

Always discuss the use of herbal treatments and essential oils with your doctor or lactation consultant, and be sure to purchase your products from a reputable source. Precautions to note regarding fennel include:

  • Do not use fennel supplements during pregnancy.
  • Essential oils that contain fennel or other herbal ingredients should be used with caution (or avoided altogether) on children.
  • Fennel may increase the risk of seizure. Therefore, you should not use fennel if you have epilepsy or any other type of seizure disorder.
  • If you put fennel on the skin, it can cause skin allergies or reactions.
  • It's possible that too much fennel can cause a decrease in breast milk supply, having the opposite of its intended effect.
  • Use extra caution if you have diabetes or hypoglycemia, as fennel can lower blood sugar levels.
  • Your baby may become sleepy after drinking breast milk containing fennel.

A Word From Verywell

Breastfeeding can be challenging, and finding natural and effective ways to boost milk supply is a relief when you're struggling. However, it's always wise to discuss the use of herbal treatments with your doctor, as these "natural" products can have significant side effects. Working with a supportive lactation consultant can help make breastfeeding a positive and rewarding experience.

5 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Badgujar SB, Patel VV, Bandivdekar AH. Foeniculum vulgare mill: A review of its botany, phytochemistry, pharmacology, contemporary application, and toxicology. Biomed Res Int. 2014;2014:842674. doi:10.1155/2014/842674

  3. Mahboubi M. Foeniculum vulgare as valuable plant in management of women's health. J Menopausal Med. 2019;25(1):1-14. doi:10.6118/jmm.2019.25.1.1

  4. Blair C. John Hopkins Medicine. Are essential oils safe for children?. Updated January 7, 2020.

  5. Skalli S, Soulaymani Bencheikh R. Epileptic seizure induced by fennel essential oil. Epileptic Disord. 2011;13(3):345-7. doi: 10.1684/epd.2011.0451

By Donna Murray, RN, BSN
Donna Murray, RN, BSN has a Bachelor of Science in Nursing from Rutgers University and is a current member of Sigma Theta Tau, the Honor Society of Nursing.