Fennel Essential Oil Health Benefits and Side Effects


Fennel (Foeniculum vulgare Mill.), family Apiaceae (Umbelliferae) is an annual, biennial or perennial aromatic herb and found in two types

  1. Sweet fennel (F. vulgare Miller var. dulce)
  2. Bitter fennel (F. vulgare Miller var. vulgare)

Fennel essential oil is extracted by steam distillation on the fresh herbage whole plant and distilled at the flowering stage or from fennel seed (fruits) (1). Fennel essential oil benefits are controls appetite antimicrobial, muscle relaxing and insecticidal properties.

Use of Fennel essential oil

Fennel essential oil has a characteristic pleasant spicy aroma that makes it excellent aromatic ingredients in baked goods, meat and fish dishes, ice-cream, and alcoholic beverages. This oil is also used as a pharmaceutical cosmetic, and perfume industry application.

Geographical distribution

Fennel essential oil is native to southern Europe and the Mediterranean area such as Bulgaria, France, Germany, Italy, Romania, Hungary, Turkey, Ukraine, Russia, Yugoslavia, India, China, Argentina and in the United States.

Common name

Fennel, Razianaj, Razianeh, Badiyan, Marsoun, Arpabodiyon

Constituents of Fennel essential oil

Fennel fruit contains essential oil mainly composed of trans-anethole, fenchone, carvone, and estragole. The ratios of essential oil from sweet and bitter fennels were found similar (average 3.00%). The presence of trans-anethole and fenchone in the varying quantities are responsible for a different taste of sweet and bitter fennel essential oil (2).

Nutrients Sweet fennel Bitter fennel
Oil content (%) 12.22 14.41
Fenchone 0.62% 5.03%
Trans-anethole 84–95% 61–75%
p-Anisaldehyde 0.24
estragole 2.87% 15.51%
Limonene 0.91 1.08
α-Pinene 0.57
y-Terpinene 0.84

 Health benefits of Fennel essential oil

Fennel essential oil has benefits like antimicrobial, anticancer, muscle relaxing, digestive, diuretic and treating respiratory and gastrointestinal disorders. 

1. Hepatoprotective activities of Fennel essential oil

Furthermore, d-limonene and β-myrcene found in fennel essential oil (0.4 ml/kg) prevents lipid peroxidation and scavenge harmful free radicals thus this oil show hepatoprotective activities and prevent liver cell damage induce by CCl4 toxicity (3).

2. Treat infantile colic and irritable bowel syndrome

Curcumin and fennel essential oil (42 mg and 25 mg) for 30 days is helpful for the relief of gastro intestinal symptoms, reduce abdominal pain intensity and the other bowel symptoms. As this oil has antispasmodic and carminative effect which makes it safe, well-tolerated and induced symptom relief in patients with IBS (4). Fennel essential oil also useful to reduce intestinal spasms and increase motility of the small intestine thus decreases the intensity of infantile (5).

3. Mosquitos repellent

Fennel essential oil containing products (5% aerosol and 8% cream) are good larvicidal activity against Anopheles, Aedes, and Armigeres with reductions on growth (84% and 70 %) at 90 min after exposure than any other cream.

Thus this oil may use to protect humans and domestic animals from vector-borne diseases and nuisance caused by mosquitoes (6).

4. Antimicrobial properties of Fennel essential oil

An antimicrobial compound known as trans-anethole which fight against various microbes such as Staphylococcus aureus, Candida albicans, Alternaria alternate, Aspergillus species and dermatophytes, Bacillus cereus, Bacillus megaterium, Bacillus pumilus, Bacillus subtilis, Escherichia coli, Klebsiella pneumonia, Micrococcus luteus, Pseudomonas putida and Pseudomonas syringae.

Thus this oil is effective against most of the foodborne pathogenic, saprophytic, probiotic, and mycotoxigenic microorganisms tested (7,8).

5. Anticancer properties of Fennel essential oil

The oil is a rich source of anethole and estragole which is beneficial to inhibit the growth of cancer cell by induction of cell cycle arrest and apoptosis (9).

6. Insecticidal properties of Fennel essential oil

It contains a good amount of fenchone and p-anisaldehyde which show insecticide effect against house dust mites such as Dermatophagoides farinae and Dermatophagoides pteronyssinus. Moreover this oil also rich in carvone which shows wonderful acaricidal activity against Tyrophagus putrescentiae (stored food mites) (10).

7. Muscle relaxing properties of Fennel essential oil during Menstrual pain

Fennel essential oil (100 mg/ml) posses nerve and muscle relaxing effect due to the presence of anol or dimethylated anethole that may have mild estrogen-like activity inhibit spasms or contraction in smooth muscle and relieve from dysmenorrheal (11).

8. Effect of Fennel essential oil on women’s health

Fennel essential oil shows a wonderful effect for the treatment of dysmenorrhea, premenstrual syndrome, amenorrhea, menopause, lactation, and polycystic ovary syndrome.

20 to 30 drops of fennel essential oil is beneficial to reduce the severity of anxiety, depression and premenstrual syndrome. Thus this oil exhibit estrogenic activity promotes menstruation and alleviates the symptoms of female climacteric, and increases libido (12).

9. Antiplatelet and antithrombotic properties of Fennel essential oil

30 mg/kg of fennel essential oil for 5 days is helpful to stop the formation of blood clots and vasorelaxant action thus prevents the paralysis. Furthermore, the intake of this oil (100 mg/kg) is also protecting from the gastric lesion, therefore, it contain gastroprotective effects (13).

10. anthelmintic properties of Fennel essential oil

100 mg/ml of fennel essential oil possess anthelmintic effects which kill Schistosoma mansoni worm (50% of both male and female), their eggs, decrease their motor activity and separate all the coupled pairs of worms due to the presence of anethole and limonene obtained from this oil (14).

11. Fennel essential oil controls the Appetite

Around 2-4 drops or 0.1-0.2 ml of fennel essential oil inhaling two times a day for 10 minutes for 8 weeks on dried cloth or cotton ball helps in controlling the appetite. As it contains trans-anethole which reduces appetite (15).

This oil (100 mg /kg) for 4 weeks also decreases in percentual feed intake by 50 % in pig (16). Thus this oil is classified as Appetite controller not as ‘appetite promoters’ by lowers the food efficiency rate rather than the feed intake in diets for both humans and animals (17).

12. Nematicidal properties of Fennel essential oil

About 200 and 150 mg/kg of fennel essential oil immobilize more than 80% of juveniles of the root-knot nematode Meloidogyne javanica at a concentration of 1000 μL/liter and inhibit nematode hatching (18).

Side effect of Fennel essential oil

Risk of epileptic seizures

Accidentally consumption of fennel essential oil by woman causes tonic-clonic seizure and remained unconscious for 45 minutes because this oil is rapidly absorbed and demonstrates primary neurotoxicity.

Therefore, a person who is suffering from epilepsy or a history of epilepsy is at high risk and should avoid such oil (19).


Accepted dosage for essential oil is 2 to 5 drops diluted with water after each meal for a healthy person.

Super summary

Fennel essential oil controls appetite when inhaled. The oil has antimicrobial, muscle relaxing and insecticidal properties. This oil also shows a wonderful effect for the treatment of dysmenorrhea, premenstrual syndrome, amenorrhea, menopause, lactation, and polycystic ovary syndrome.

Edited By: Dr.Asha Jyoti Bharati

Trending Articles on Essential Oils

  1. Lemon Grass Essential Oil Health Benefits
  2. Tea Tree Oil Health Benefits & Side Effects
  3. Eucalyptus Oil Health Benefits 
  4. Lemon Essential Oil Health Benefits & Side Effects
  5. Peppermint Essential Oil Health Benefits & Side Effects
  6. Rosemary Essential Oil Health Benefits & Side Effects
  7. Lavender Essential Oil Health Benefits & Side Effects
  8. Ginger Essential Oil Health Benefits & Side Effects
  9. Turmeric Essential Oil Health Benefits & Side Effects
  10. Thyme Essential Oil Health Benefits & Side Effects


  1.   https://www.ncbi.nlm.nih.gov/pubmed/24005011
  2.   https://www.ncbi.nlm.nih.gov/pubmed/18780240
  3. https://www.ncbi.nlm.nih.gov/pubmed/12727504/
  4.   https://www.ncbi.nlm.nih.gov/pubmed/27308645
  5.   https://www.ncbi.nlm.nih.gov/pubmed/12868253
  6.   https://www.ncbi.nlm.nih.gov/pubmed/15532688
  7.   https://www.ncbi.nlm.nih.gov/pubmed/22805920
  8.     https://www.ncbi.nlm.nih.gov/pubmed/30328892
  9. https://www.ncbi.nlm.nih.gov/pubmed/30914034
  10. https://www.ncbi.nlm.nih.gov/pubmed/15137830
  11. https://www.ncbi.nlm.nih.gov/pubmed/11448553/
  12. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6487283/
  13. https://www.ncbi.nlm.nih.gov/pubmed/17709257
  14. https://www.ncbi.nlm.nih.gov/pubmed/26172330
  15. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4525133/
  16. https://www.ncbi.nlm.nih.gov/pubmed/17083431
  17. https://www.ncbi.nlm.nih.gov/pubmed/16691041/
  18. https://www.ncbi.nlm.nih.gov/pubmed/18944489/
  19. https://www.ncbi.nlm.nih.gov/pubmed/21865126


Please enter your comment!
Please enter your name here