Remedy · herb & leaf
Fennel seed: bloating, infant colic and what the evidence says
A traditional after-dinner seed for wind and bloating, recognized by European regulators on the strength of long use rather than trials. Colic studies in babies are small.
By the editors of Alimentotherapy Last reviewed 3 min read Not medical advice
Fennel
Foeniculum vulgare
Best-supported use: Bloating and wind after meals
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The short answer
Fennel seed has a long record as a remedy for bloating and wind, and the European Medicines Agency accepts it as a traditional herbal medicine for mild cramping digestive complaints, but that rests on decades of use rather than clinical trials EMA. A few small trials in babies with colic looked promising, yet reviews call them flawed, and European regulators advise against fennel medicines for children under fourPerry 2011; EMA.
The evidence, use by use
Each claim graded on human studies only. How we grade
| Use | Grade | What the research found |
|---|---|---|
| Bloating, wind and mild cramping after meals | Limited | Registered in the EU as a traditional herbal medicine for these symptoms based on at least 30 years of use. Clinical trials are limited; lab studies show fennel extracts relax smooth muscle. EMA |
| Infant colic | Limited | One trial of 125 babies found a fennel seed oil emulsion relieved colic in 65% versus 24% on placebo. Systematic reviews call such results encouraging but note every trial had major flaws and lacked replication. Alexandrovich 2003; Perry 2011; Anheyer 2017 |
| Cough with a cold (as an expectorant) | Limited | Accepted by EMA as a traditional use, supported by animal and lab data rather than human trials. EMA |
How it is used
The "seeds" are the dried fruits of the fennel plant. In South Asia they are chewed after meals, sometimes sugar-coated, and across Europe they are crushed and steeped as a tea. EMA lists sweet fennel fruit taken by mouth as a tea or tablet, usually three to four times a day for no more than one to two weeksEMA.
In the kitchen
Crush a teaspoon of seeds lightly in a mortar just before use, pour on a cup of freshly boiled water, cover and steep for about ten minutes so the aromatic oils stay in the cup. See herbal infusions for the method in detail.
Fennel seed is in most spice aisles. If you want loose seed or single-herb fennel tea in bulk, iHerb stocks both.
Fennel for babies with colic
In a Russian trial of 125 infants aged two to twelve weeks, a fennel seed oil emulsion ended colic (by a standard crying-time definition) in 65% of treated babies versus 23.7% given placebo, with no side effects reported Alexandrovich 2003. A 2011 systematic review of complementary treatments for colic found encouraging results for fennel extract and mixed herbal teas but stressed that all the trials had major limitations and none had been independently repeated Perry 2011. A 2017 review in Pediatrics reached a similar cautious conclusion Anheyer 2017.
There is also a safety question specific to fennel. It contains estragole, which causes cancer in rodents at high doses. The EMA judges short-term adult use at recommended doses not to pose a significant risk, but says exposure in young children, and in pregnancy and breastfeeding, should be kept to a minimumEMA.
Safety
Talk to your pediatrician before giving a baby fennel tea, oil or drops. Babies need breast milk or formula, and teas can displace feeds. Crying with fever, vomiting, poor feeding or poor weight gain needs medical attention.
Why it might work
Fennel’s aroma comes from oils, mainly anethole and estragole. In lab studies, alcohol extracts and essential oil of fennel relaxed contracted smooth muscle, which fits its traditional use for cramping and windEMA. Lab findings show plausibility, not proof that a cup of tea works.
Before you try it: safety and interactions
Who should avoid it or ask first
- You are allergic to fennel.
- The child is under four: EMA does not recommend fennel medicines at that age, and estragole exposure in young children should be minimized.
- You plan to use concentrated fennel essential oil by mouth: it is far stronger than the seed.
Possible side effects
- Allergic reactions of the skin or airways, the most commonly reported side effect.
Pregnancy and breastfeeding
Fennel used as a kitchen spice is fine. EMA advises against fennel medicines in pregnancy and breastfeeding as a precaution, because they have not been tested and because of estragole. EMA; EMA
Medicine interactions
We found no well-documented medicine interactions for fennel at food amounts. That is not proof there are none: tell your pharmacist about any herb or supplement you take.
Check another food or medicine in the interactions list.
Common questions
Does fennel tea help with bloating?
It may, but the evidence is mostly traditional. The European Medicines Agency accepts sweet fennel fruit as a traditional herbal medicine for mild bloating and wind, based on more than 30 years of use rather than clinical trials.
Is fennel tea safe for babies with colic?
Ask your pediatrician first. Small trials found fennel preparations reduced colic, but reviews say the trials were flawed, and the EMA does not recommend fennel medicines under age four, partly because of a compound called estragole.
Sources
Primary research and government sources, each checked on the date this page was reviewed.
- GuidelineEuropean Medicines Agency, Committee on Herbal Medicinal Products. Foeniculum vulgare (sweet fennel fruit): HMPC assessment report summary for the public. EMA/HMPC/411665/2008.
- GuidelineEuropean Medicines Agency. Public statement on the use of herbal medicinal products containing estragole. EMA/HMPC/137212/2005.
- PubMedAlexandrovich I, et al. The effect of fennel (Foeniculum vulgare) seed oil emulsion in infantile colic: a randomized, placebo-controlled study. Altern Ther Health Med. 2003. PMID 12868253.
- PubMedPerry R, Hunt K, Ernst E. Nutritional supplements and other complementary medicines for infantile colic: a systematic review. Pediatrics. 2011. PMID 21444591.
- PubMedAnheyer D, et al. Herbal medicines for gastrointestinal disorders in children and adolescents: a systematic review. Pediatrics. 2017. PMID 28562281.
Keep reading
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- Kitchen practiceHerbal infusionsSteeping a leaf or simmering a root is the oldest way to take a plant. Most common kitchen herbs are safe as tea; a few are not, and the label on the box tells you less than you might think.