Fennel

Related Terms

Adas (Indonesian, Malay), adas pedas (Malay), alpha-pinene, anason dulce (Romanian), aneth doux (French), anethole, Anethum foeniculum, anis (Tagalog), Anthemis cotula (dog fennel), Apiaceae (parsley family), aptechnyj ukrop (Russian), apteegitilliseemne (Estonian), badesopu (Kannada), badishep (Marathi), bitter fennel, carosella, c?y th? l? (Vietnamese), common fennel, ?desk?m?ny (Hungarian), estragole (methyl chavicol), Fenchel (German), fenchone, fenheli parastie (Latvian), fenhelis (Latvian), fenicol, fenikel (Slovak), fenkel, fenkhel (Russian), fenkoli (Finnish), fenkolo (Esperanto), fennel honey syrup, fennel oil, fenneru (Japanese), fennika (Icelandic), fennikel (Danish, Norwegian), fenouil (French), fenoun (Proven?al), fenykl (Czech), ferula communis (giant fennel), finocchio (Italian), finokio (Greek), florence fennel, Foeniculi antheroleum, Foeniculum capillaceum, Foeniculum officinale, Foeniculum vulgare, Foeniculum vulgare ssp. piperitum (bitter fennel), Foeniculum vulgare Mill. var. dulce (sweet fennel), Foeniculum vulgare Mill. var. vulgare (bitter fennel fruits), fructus Foeniculi, funcho (Portuguese), garden fennel, guamoori, haras (Tagalos), harilik apteegitill (Estonian), hinojo (Spanish), hoehyang (Korean), hoehyang-pul (Korean), h?i huong (Vietnamese), hui xiang (Mandarin Chinese), jinten manis (Indonesian), kama (Georgian), komorac (Serbian, Croatian), kop?r (Albanian), koper wloski (Polish), koromac (Croatian), large cummin, large fennel, limonene, lus an t'saiodh (Gaelic), madhurika (Sanskrit), maduru (Sinhala), marac (Albanian), maratho (Greek), mehul (Basque), mellet karee (Thai), merula obisnuita, mieloi (Basque), miur belar (Basque), molura (Romanian), morach (Bulgarian), moti saunf (Hindi), mouri (Bengali), paciolis (Lithuanian), pak chi duanha (Thai), pan modhuri (Oriya), paprastasis pankolis (Lithuanian), pedda jilakarra (Telugu), pennel (Korean), perunjiragam (Tamil), phak si (Laotian), phong karee (Thai), phytoestrogen, razianaj (Arabic), razianeh (Farsi), razyana (Azeri), rezene (Bulgarian, Turkish), samit (Armenian), samong-saba (Burmese), saunf (Hindi), shamaar (Arabic), shamar (Arabic), shamari (Swahili), shamraa (Arabic), shatpushpa (Sanskrit), shoap (Marathi), shoumar (Arabic), shumar (Arabic, Hebrew), siu wuih heung (Cantonese), sladki komarcek (Slovenian), sladkij ukrop (Russian), sohikirai (Tamil), so-hoehyang (Korean), sombu (Tamil), sonf (Urdu), sopu (Telugu), spice of the angels, sulpha, sweet cumin, sweet fennel, thian-klaep (Thai), tian hi xiang (Mandarin Chinese), ti?u h?i huong (Vietnamese), tihm wuih heung (Cantonese), trans-anethole, uikyo (Japanese), ukrop sladki (Russian), Umbilliferae (parsley family), venkel (Dutch, Estonian), wariari, wild fennel, wuih heung (Cantonese), xiao hui xiang (Mandarian Chinese), yira (Thai).

Background

Fennel (Foeniculum vulgare) is a native plant of the Mediterranean region. The bulbs, leaves, and seeds are commonly eaten. Fennel has a mild licorice flavor and celery-like texture. It is a good source of potassium.
Fennel fruits have been used as a traditional herbal medicine in Europe and China. Fennel tea has been used as a remedy to treat indigestion in infants.
Good human evidence suggests that fennel reduces colic in infants. According to limited human evidence, fennel may also reduce painful menstruation and protect against damage caused by ultraviolet light. Fennel tea alone or in combination with other herbs is popularly used for gastrointestinal disorders and to improve digestion. However, studies evaluating fennel alone for this use in humans are needed.

Evidence Table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *


Limited research suggests that fennel may reduce infantile colic. Additional studies are needed to confirm these promising findings.

 B


Limited research suggests that fennel may reduce infantile colic. Additional studies are needed to confirm these promising findings.

 B


Preliminary evidence suggests that fennel may help relieve a cough from using certain blood pressure-lowering drugs called ACE inhibitors (ACEI). However, there is insufficient evidence to make a conclusion for or against its use for ACEI-induced cough.

 C


Preliminary evidence suggests that fennel may help relieve a cough from using certain blood pressure-lowering drugs called ACE inhibitors (ACEI). However, there is insufficient evidence to make a conclusion for or against its use for ACEI-induced cough.

 C


According to preliminary evidence, fennel, when combined with other herbal agents, may decrease pain associated with colitis (inflammation of the colon). More evidence is needed before further conclusions can be drawn.

 C


According to preliminary evidence, fennel, when combined with other herbal agents, may decrease pain associated with colitis (inflammation of the colon). More evidence is needed before further conclusions can be drawn.

 C


Evidence evaluating the effects of fennel combined with other herbal agents suggests that it may reduce constipation. Studies evaluating fennel alone are needed before further conclusions may be drawn.

 C


Evidence evaluating the effects of fennel combined with other herbal agents suggests that it may reduce constipation. Studies evaluating fennel alone are needed before further conclusions may be drawn.

 C


Fennel has been used to treat painful menstruation. Although preliminary research is promising, further research is needed before conclusions can be drawn.

 C


Fennel has been used to treat painful menstruation. Although preliminary research is promising, further research is needed before conclusions can be drawn.

 C


Fennel has been studied in women with hirsutism (excessive facial and body hair), due to its estrogenic effects. More research is needed before further conclusions can be drawn.

 C


Fennel has been studied in women with hirsutism (excessive facial and body hair), due to its estrogenic effects. More research is needed before further conclusions can be drawn.

 C


According to preliminary evidence, sweet fennel combined with other aromatherapy agents may reduce nausea in patients in hospice programs. More evidence is needed before a conclusion can be drawn.

 C


According to preliminary evidence, sweet fennel combined with other aromatherapy agents may reduce nausea in patients in hospice programs. More evidence is needed before a conclusion can be drawn.

 C


Topical fennel extract improved sun protection factor (SPF) and decreased ultraviolet light-induced skin reddening. More research is needed in this area.

 C


Topical fennel extract improved sun protection factor (SPF) and decreased ultraviolet light-induced skin reddening. More research is needed in this area.

 C
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)

Tradition / Theory

The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.

Dosing

Adults (18 years and older)
For general use as a tea, 1-2 grams of crushed or ground fruit or seed may be added to 150 milliliters of boiling water for 5-10 minutes and strained. One cup of tea has been taken by mouth three times daily. As an antioxidant, doses of 205, 700, and 4,600 micrograms of aqueous extract taken by mouth have been suggested.
For angiotensin converting enzyme (ACE) inhibitor-induced cough, 1-1.5 grams of fennel fruit has been taken by mouth up to three times daily.
For painful menstruation, 25 drops of a 2% concentration of fennel fruit has been taken by mouth every four hours for five days. Thirty drops of fennel every six hours for the first three days of menses have also been taken by mouth, as has 46 milligrams of fennel, taken at the onset of pain or bleeding, five times daily for three days.
For stomach discomfort, 0.1-0.6 milliliters of fennel oil, 5-7 grams of fennel seed, 10-20 grams of fennel syrup and honey, or 5-7.5 grams of tincture has been taken by mouth daily. One to three grams of fennel in 150 milliliters of infusion, 1-3 milliliters of fluid extract 1:1 (grams per milliliter), or 5-15 milliliters of fennel tincture 1:5 (grams per milliliter) have been taken 2-3 times daily between meals. Also, 0.2-0.7 grams of dry extract of fennel 3.9-4.9:1 (weight/weight) has been taken 2-3 times daily.
For inflammation of mucous membranes in the upper respiratory tract, 0.1-0.6 milliliters of fennel oil (equivalent to 0.1-0.6 grams of herb), 5-7 grams of fennel seed, 10-20 grams of fennel syrup or honey, or 5-7.5 grams of tincture has been taken by mouth daily. One to three grams of fennel infusion in 150 milliliters of water, 1-3 milliliters of fluid extract (1:1 grams per milliliter), 5-15 milliliters of tincture 1:5 (grams per milliliter), or 0.2-0.7 grams of dry extract 3.9-4.9:1 (weight/weight) has been taken by mouth 2-3 times daily between meals.
For excess hair growth, 1% and 2% fennel cream has been applied to the skin twice daily for 12 weeks.
For ultraviolet protection, 2% and 5% naturally active botanical fennel have been used in an emulsion on the skin.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Interactions

Interactions with Drugs
Fennel may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants (blood thinners) such as warfarin (Coumadin?) or heparin, antiplatelet drugs such as clopidogrel (Plavix?), and nonsteroidal anti-inflammatory drugs such as ibuprofen (Motrin?, Advil?) or naproxen (Naprosyn?, Aleve?).
Fennel may lower blood sugar levels. Caution is advised when using medications that may also lower blood sugar. Patients taking insulin or drugs for diabetes by mouth should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
Fennel may cause low blood pressure. Caution is advised in patients taking drugs that lower blood pressure.
Fennel may interfere with the way the body processes certain drugs using the liver's cytochrome P450 enzyme system. As a result, the levels of these drugs may be changed in the blood, and may cause increased or decreased effects or potentially serious adverse reactions. Patients using any medications should check the package insert and speak with a qualified healthcare professional, including a pharmacist, about possible interactions.
Because fennel contains estrogen-like chemicals, the effects of drugs believed to have estrogen-like properties may be altered.
Use of fennel and ciprofloxacin (Cipro?) may lead to decreased bioavailability of ciprofloxacin. Theoretically, fennel may also interfere similarly with other fluoroquinolone antibiotics.
Although not well studied in humans, pretreatment with fennel essential oil may enhance the skin absorption of various topical agents, such as trazodone.
Fennel may also interact with antibiotics, anticancer agents, antifungals, anti-inflammatory agents, antiobesity agents, antispasmodics, cholinesterase inhibitors, diuretics (drugs that increase urination), drugs that suppress the immune system, gastrointestinal agents, glaucoma agents, iron salts, pain relievers, vasodilators, and vasopressors.

Attribution

This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

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