Fennel was a popular medicinal and culinary herb and vegetable to the ancient Romans and Anglo-saxins. Most people are familiar with fennel in one way or another, wether it's through cooking, gardening, or due to its powerful medicinal actions.
Fennel has well over 100 common names due to its worldwide popularity as a medicinal and culinary herb. It also has the ability to grow in a huge range of climates, and can be found virtually world-wide.
Likely the best actions of fennel are on the digestive tract, providing carminative (gas-eliminating), and spasmolytic (relaxes the muscles) activities inside the digestive tract.
In the respiratory tract, fennel seed acts as an expectorant (helps remove mucous and foreign substances).
For females, fennel acts as an estrogenic herb and can help with amenorrhea (lack of menstrual period), and improve the flow of milk in nursing mothers.
[2, 3, 4, 13]
- Appetite stimulant
- Estrogenic 
- Chemoprotective 
- Cytoprotective 
- Hypoglycemic 
Syn: F. officinalis
Seeds, leaves, roots
1-3 g in 150 ml water. Take 2/day.
1-2 drops in 2 cups of water
Liquid Extract (1:2)
[3, 4, 13]
- Digestive Conditions:
- Infantile colic
- Spasmodic gastric complaints
- Chronic non-specific colitis
- Abdominal pains
- Respiratory Conditions:
- Upper respiratory catarrh
- Pharyngitis (gargle)
- Abdominal pain
- Suppressed lactation
- 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 )
- Eye infection (as a wash)
- Strengthen eyesight (as a wash)
- Mouth ulcers (as a wash)
- Foeniculi fructus (Latin)
- Bitterfenchel (Germany)
- Finocchio (Italy)
- Xian hui xiang (China)
- Erva-doce (Brazil)
- Hinojo (Ecuador)
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 .
It was mentioned by Pliny, and other old herbalists for its use in strengthening sight .
Fennel was also a common culinary herb, especially used in combination with fish , 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 .
Fennel seeds have been found in the tombs of Egyptian pharaohs .
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].
Fennel is a bienniel, or perennial herb that can grow to about 2m in height [2, 3]. All parts of the plant, but especially the seeds, are aromatic .
The plant resembles that of dill, with feathery leaves, and bright green colour.
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 .
It is cultivated on a large scale in the South of France, Russia, Persia, and India .
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 .
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. .
- Volatile oils
- Anisic acid
- Anisic aldehyde
- Minerals Ca and K
- Fatty acids
Pharmacology and Medical Research:
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 .
Fennel seed extract has been shown active against a wide range of bacteria, fungi, protozoa, virus', and parasites .
Fennel essential oil regulates the motility of smooth muscles in the intestine and relieves intestinal gas .
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 .
Fennel has been found in multiple studies to produce estrogenic activity in both male and female mice and rats . In female humans, fennel oil is reported to exhibit estrogenic activity and promote menstruation and increase libido .
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 .
Fennel has a long history of use as a galactagogue . 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].
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 . 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 .
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 .
This makes fennel a candidate for further study as a possible treatment for neurodegenerative disorders such as dementia and Alzheimers.
Toxicity and Contraindications:
The LD50 of fennel oil orally varies from 1.33g/kg to 4.5 ml/kg .
In another study mice given fennel plant extract at a dose of 2000mg/kg showed no indications of toxicity or mortality . This demonstrates the high level of safety of fennel extracts.
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. .
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 .
Children however should not consume fennel for long durations due to its estrogen content .
Avoid using high doses if hepatic disorders present .
Traditional Chinese Medicine:
Pinyin: Xiao Hui Xiang
Taste: Pungent 
Energy: Warm 
Channels: Liver, kidney, spleen, stomach 
Actions: Expels cold, relieves pain, regulates the flow of Qi in the stomach 
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. . Used to dispel cold .
- For dyspepsia combine with wormwood, caraway, and peppermint
- For colic mix with lemon balm, chamomile, vervain, and liquorice
The Sunlight Experiment
Updated: March 2017
Recent Blog Posts:
- 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.
- 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
- Bone K, Mills S. (2013). Principles and Practice of Phytotherapy. Elsevier health. China. (Pg. 557-565).
- A Modern Herbal. (1931). Fennel. Retrieved from http://www.botanical.com/botanical/mgmh/f/fennel01.html
- 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
- 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
- H. Ozbek, S. Ugras, H. Dulger (2003). Hepatoprotective effect of Foeniculum vulgare essential oil, Fitoterapia, vol. 74, no. 3, pp. 317–319
- 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.
- 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
- 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
- M. Albert-Puleo, “Fennel and anise as estrogenic agents, (1980). Journal of Ethnopharmacology, vol. 2, no. 4, pp. 337–344
- 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
- Bone, K. (2003). A clinical guide to blending liquid herbs: Herbal formulations for the individual patient. Edinburgh [u.a.: Churchill Livingstone. (Pg. 206-209).
- Wu, J. N. (2005). An illustrated Chinese materia medica. New York: Oxford University Press. (Pg. 314-315).