Fennel

There are two main varieties used in herbal medicine. Sweet fennel (Foeniculum vulgare var. dulce) has a higher proportion of anethole, the compound behind its gentle, aniseed-like sweetness. Bitter fennel (var. vulgare) contains more fenchone, giving it a sharper, more camphor-like taste. Both share similar traditional uses for digestive comfort, but sweet fennel is generally preferred in formulas for children and for anyone who finds bitter herbs hard to take.

No, although they’re close relatives in the same plant family and share the aromatic compound anethole, which is why they taste alike. Aniseed (Pimpinella anisum) is a separate plant with a slightly stronger, more liquorice-like flavour. Traditionally, both have been used for wind and digestive discomfort, and you’ll often see them paired together, but fennel is typically the milder and sweeter of the two.

Most of fennel’s active aromatic compounds sit in tiny oil channels within the seed. Lightly crushing the seeds just before use breaks these open so the volatile oils can be released into the water. It’s also a good idea to cover your cup while it steeps, so those aromatic oils stay in the tea rather than escaping with the steam. Liquid extracts get around this by drawing the compounds out during manufacture, which also gives a more consistent strength from dose to dose.

Yes. Fennel has a long traditional reputation as a galactagogue, a herb used to support breast milk supply, and it often appears in traditional “nursing teas” alongside herbs like fenugreek and blessed thistle. The scientific evidence for this use is limited, so it’s best viewed as traditional rather than proven. If you’re breastfeeding, talk to your midwife, lactation consultant or healthcare professional before taking fennel in concentrated forms such as extracts.

Fennel naturally contains a small amount of a compound called estragole. At the levels found in normal culinary use this isn’t considered a concern, but European regulators have taken a cautious approach to concentrated fennel preparations for very young children and for long-term use. This is why it matters to choose a product formulated and dosed for your child’s age, follow the label directions, and use fennel for short periods as needed rather than continuously. If you’re unsure, check with your healthcare professional.