Fennel (Foeniculum vulgare)


Fennel Summary

Fennel is a popular culinary herb and medicinal species across the world. It's so widely distributed that there are reportedly over 100 common names for the herb depending on where you are in the world.

The best use of fennel is likely to be its activity on the digestive tract. It is high in volatile oils, and works to relax the smooth muscle of the digestive tract, and reduce the buildup of gas in the digestive tract. The carminative action of fennel is among the most reliable in the world.

Traditional uses of fennel mainly combine it with cooking, such as with fatty meals like fish or meat to eliminate any side effects from the large meal, while imparting its own unique flavour.

+ Indications


  • Dyspepsia
  • Bloating
  • Flatulence
  • Infantile colic
  • Spasmodic gastric complaints
  • Chronic non-specific colitis
  • Anorexia
  • Obesity
  • Vomiting
  • Diarrhoea
  • IBS
  • Abdominal pains
  • Abdominal pain
  • Upper respiratory catarrh
  • Pharyngitis (gargle)
  • Suppressed lactation
  • Amenorhhea
  • Cancer
  • Leukorhea
  • Improving milk flow in nursing mothers
  • To improve memory
  • Mild depression


  • Inhibit facial hair in women with idiopathic hirsutism (not touched upon here, see references [9])
  • Eye infection (as a wash)
  • Strengthen eyesight (as a wash)
  • Arthritis
  • Mouth ulcers (as a wash)

+ Contraindications

  • Don't use in therapeutic doses long-term.

Herbal Actions:

  • Carminative
  • Appetite suppressant
  • Spasmolytic
  • Galactagogue
  • Antimicrobial
  • Expectorant
  • Estrogenic
  • Cytoprotective
  • Hypoglycemic
  • Nootropic

What Is Fennel Used For?

Fennel is mainly used for the digestive system as a carminative to relieve gas and bloating, and to relax the smooth muscle of the digestive tract with dyspepsia, cramping, colic, vomiting, and diarrhea. It can also be used for IBS and other inflammatory conditions of the bowel and is a useful appetite stimulant for anorexia.

In the respiratory tract, fennel is used as an expectorant, and spasmolytic for coughs. Fennel is also used to stimulate the production of milk in breastfeeding mothers, and as a nootropic to improve learning and memory.

Topically, fennel is used for ulcerations, cuts, bruises, eye infections, and arthritis.


Traditional Uses of Fennel

+ Western Herbal Medicine

Fennel was commonly used by the ancient Romans for its succulent shoots, and for the strong flavour and aromatic nature of the seeds. It was said to promote longevity, and provide both strength and courage [4].

It was mentioned by Pliny, and other old herbalists for its use in strengthening sight [4].

Fennel was also a common culinary herb, especially used in combination with fish [4], where it is still a common pairing today.

It was used traditionally to improve appetite in anorexic individuals, as well as to decrease appetite in obese individuals [3].

+ Traditional Chinese Medicine

Pinyin: Xiao Hui Xiang

Taste: Pungent [14]

Energy: Warm [14]

Channels: Liver, kidney, spleen, stomach [14]

Actions: Expels cold, relieves pain, regulates the flow of Qi in the stomach [14]

Fennel is known as xian hui xiang in China. It is used in Chinese medicine to treat cold conditions of any kind in the lower abdominal region. This includes cold hernia like conditions involving pain, cold stomach conditions, and may be identified by the presence of abdominal pain, indigestion, weak appetite, and vomiting. [3]. Used to dispel cold [13].

+ Other Traditional Medical Systems

Fennel seeds have been found in the tombs of Egyptian pharaohs [3].

Fennel also has a long history of use in the traditional Chinese medical system (See below), as well as Ayurvedic, Unani, Siddha, and Indian and Iranian traditional systems [2, 5].


Herb Details: Fennel

Weekly Dose

Part Used

Seeds, leaves, roots

Family Name



Thought to originate from the Mediterranian but has spread all over the world.

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Constituents of Interest

  • Anechol
  • Dianethole

Common Names

  • Fennel
  • Foeniculi fructus (Latin)
  • Bitterfenchel (Germany)
  • Finocchio (Italy)
  • Xian hui xiang (China)
  • Erva-doce (Brazil)
  • Hinojo (Ecuador)







Duration of Use

  • Avoid long-term use in therapeutic doses. Long-term culinary use recommended.

Botanical Information

Fennel is a member of the Apiaceae family of plants, which comprises 434 genera and 3700 species. The vast majority of the Apiaceae species are arromatic, and include many well known herbal medicinal species or culinary spices.

Some of the most common herbs in this family include:

  • Angelica archangelica (Angelica)
  • Pimpinella anisum (Anise)
  • Ferula assa-foetida (Asafoetida)
  • Carum carvi (Caraway)
  • Daucus carota (Carrot)
  • Apium graviolens (Celery)
  • Anthriscus cerefollium (Chervil)
  • Coriandrum sativum (Coriander)(Cilantro)
  • Cuminum cyminum (Cumin)
  • Anethum graveolens (Dill)
  • Conium chaerophylloides (Dill)

Habitat Ecology, and Distribution:

Fennel is generally regarded as indigenous to the shores of the Mediterranean, spreading eastward towards India [2, 4]. It has spread far and wide however, and has been cultivated in nearly every country [1].

It is cultivated on a large scale in the South of France, Russia, Persia, and India [4].


Harvesting Collection, and Preparation:

Fennel seed, or fennel seed essential oil can be used as a flavouring for alcoholic beverages or teas, and is often added to mouthwashes and toothpastes to add flavour and antimicrobial actions [3].


Pharmacology & Medical Research

+ Antinflammatory

The anti-inflammatory activity of fennel seed are suggested to act through the cyclooxygenase, and lipoxygenase pathways and have been found effective in various mice models of inflammation [2, 6]. The immunosuppressive anti-inflammatory actions of fennel suggest a mechanism of action of its anti-allergy effects as well [6].

+ Antimicrobial

Fennel seed extract has been shown active against a wide range of bacteria, fungi, protozoa, virus', and parasites [2].

+ Carminative

Fennel essential oil regulates the motility of smooth muscles in the intestine and relieves intestinal gas [2].

+ Digestive Effects

Fennel extract (aqueous) increases gastric acid secretion in rats, including amylase and trypsin in pancreatic juice, lipase and amylase in the small intestine, bile in the gallbladder [15].

+ Estrogenic

Fennel has been found in multiple studies to produce estrogenic activity in both male and female mice and rats [2]. In female humans, fennel oil is reported to exhibit estrogenic activity and promote menstruation and increase libido [11].

In a more recent study than this, fennel was found to have estrogenic qualities based on its ability to significantly inhibit the prostaglandin E2, and reduce the frequency of uterine contractions that are subsequently induced by prostaglandin E2. Researchers conducting this study concluded that fennel possesses strong estrogenic activity [10].

+ Galactagogue

Fennel has a long history of use as a galactagogue [2]. Recent scientific study has found the activity of several of the polymers of anethole contained within the plant such as dianethole, and photoanethole may be responsible. They are suggested to act similarly to dopamine due their structural similarity. Dopamine inhibits the secretion of prolactin, which is the milk producing hormone. The anethole polymers may then act by competing with dopamine at the receptor sites and subsequently inhibiting the antisecretory activity of dopamine in this regard [2, 11].

+ Hepatoprotective

Fennel seed essential oil has been found to provide potent hepatoprotective effects against acute hepatotoxicity from carbon tetrachloride (a well known model to induce hepatotoxicity) in rats [2]. The essential oil content contains delta-limonene, and beta-myrecene, which are suggested to play a key role in the hepatoprotection of fennel essential oil against carbon tetrachloride [7].

+ Nootropic

Fennel extract (whole plant) has been shown to increase the inhibition of acetylcholinesterase in mice brains [2, 8]. This a common mechanism of action in nootropic formulas and substances.

It was also found to reduce the amnesic effects of scopolamine and age-induced memory deficits in mice [2].

This makes fennel a candidate for further study as a possible treatment for neurodegenerative disorders such as dementia and Alzheimers.



The volatile oil of the seeds are considered the most medicinal component of fennel. Each species of fennel contains a slightly different volatile oil makeup. [4]. [2-4, 13]

+ Constituent Breakdown

  • Volatile oil
    • Anechol
    • Fenchone
    • d-pinene
    • Phelandrine
    • Anisic acid
    • Anisic aldehyde
    • Limonenel
  • Flavonoids
  • Protein
  • Minerals Ca and K
  • Sugars
  • Vitamins
  • Fatty acids

Clinical Applications Of Fennel:

Fennel is reliable as a digestive aid for conditions including dyspepsia, irritable bowel syndrome, bloating and gas, diarrhea, and colic. It is also useful for lactating mothers to stimulate the flow of bile. The essential oil is antiseptic and antinflammatory and can be useful in topical applications to improve the skin, treat wounds, and can be diluted to be used as a gentle eyewash.

There has been a lot of evidence recently for fennels application as a nootropic to imprive learning and memmory.



Fennel has proven to have a high level of safety. Caustion is advised when using concentrated essential oils of any kind.

Be cautious of some of the common adulterants associated with this herb. Some of the lower quality fennel seed on the market today has already undergone steam distillation, which removes most of the volatile oils desired from this plant. These seeds will appear much darker in colour, and have a diminished scent. They will also sink immediately in water. Some suppliers, will colour the seeds so as to appear normal. To determine this, you can rub the seeds between your fingers and if they have been coloured, the colour will begin to rub off onto your finger tips. [4]. 

The Commission E recommends fennel not to be taken for longer than several weeks. Many authority sources disagree with this statement however, stating that fennel is safe to consume for long periods of time [3]. 

Children however should not consume fennel for long durations due to its estrogen content [3]. 

Avoid using high doses if hepatic disorders present [3]. 

The LD50 of fennel oil orally varies from 1.33g/kg to 4.5 ml/kg [3].

In another study mice given fennel plant extract at a dose of 2000mg/kg showed no indications of toxicity or mortality [12]. This demonstrates the high level of safety of fennel extracts.



For dyspepsia combine with wormwood, caraway, and peppermint

For colic mix with lemon balm, chamomile, vervain, and liquorice



Justin Cooke, BHSc

The Sunlight Experiment

(Updated November 2018)


Recent Blog Posts:


  1. B. Muckensturm, D. Foechterlen, J. P. Reduron, P. Danton, and M. Hildenbrand, (1997). Phytochemical and chemotaxonomic studies of Foeniculum vulgare, Biochemical Systematics and Ecology, vol. 25, no. 4, pp. 353–358, 1997.

  2. Badgujar, S. B., Patel, V. V., & Bandivdekar, A. H. (2014). Foeniculum vulgareMill: A Review of Its Botany, Phytochemistry, Pharmacology, Contemporary Application, and Toxicology. BioMed Research International, 2014, 1-32. doi:10.1155/2014/842674

  3. Bone K, Mills S. (2013). Principles and Practice of Phytotherapy. Elsevier health. China. (Pg. 557-565).

  4. A Modern Herbal. (1931). Fennel. Retrieved from http://www.botanical.com/botanical/mgmh/f/fennel01.html

  5. R. Rahimi and M. R. S. Ardekani, (2013). Medicinal properties of Foeniculum vulgare Mill. in traditional Iranian medicine and modern phytotherapy, Chinese Journal of Integrative Medicine, vol. 19, no. 1, pp. 73–79

  6. E. Choi and J. Hwang, (2004). Antiinflammatory, analgesic and antioxidant activities of the fruit of Foeniculum vulgare,” Fitoterapia, vol. 75, no. 6, pp. 557–565

  7. H. Ozbek, S. Ugras, H. Dulger (2003). Hepatoprotective effect of Foeniculum vulgare essential oil, Fitoterapia, vol. 74, no. 3, pp. 317–319

  8. H. Joshi and M. Parle, (2006). Cholinergic basis of memory-strengthening effect of Foeniculum vulgare Linn, Journal of Medicinal Food, vol. 9, no. 3, pp. 413–417.

  9. K. Javidnia, L. Dastgheib, S. M. Samani, and A. Nasiri, (2003). Antihirsutism activity of Fennel (fruits of Foeniculum vulgare) extract: a double-blind placebo controlled no. 6-7, pp. 455–458

  10. S. N. Ostad, M. Soodi, M. Shariffzadeh, N. Khorshidi, and H. Marzban, (2001). The effect of fennel essential oil on uterine contraction as a model for dysmenorrhea, pharmacology and toxicology study. Journal of Ethnopharmacology, vol. 76, no. 3, pp. 299–304

  11. M. Albert-Puleo, “Fennel and anise as estrogenic agents, (1980). Journal of Ethnopharmacology, vol. 2, no. 4, pp. 337–344

  12. R. Naga Kishore, N. Anjaneyulu, M. Naga Ganesh, and N. Sravya, (2012). Evaluation of anxiolytic activity of ethanolic extract of Foeniculum vulgare in mice model, International Journal of Pharmacy and Pharmaceutical Sciences, vol. 4, no. 3, pp. 584–586

  13. Bone, K. (2003). A clinical guide to blending liquid herbs: Herbal formulations for the individual patient. Edinburgh [u.a.: Churchill Livingstone. (Pg. 206-209).

  14. Wu, J. N. (2005). An illustrated Chinese materia medica. New York: Oxford University Press. (Pg. 314-315).

  15. Vasudevan, K., Vembar, S., Veeraraghavan, K., & Haranath, P. S. (2000). Influence of intragastric perfusion of aqueous spice extracts on acid secretion in anesthetized albino rats. Indian journal of gastroenterology: official journal of the Indian Society of Gastroenterology, 19(2), 53-56.