Fennel Essential Oil Benefits and Therapeutic Uses

Fennel is an ancient herb recognized and used for its distinct aroma and flavor. The plant originated in the Mediterranean region but was cultivated worldwide. The earliest application of fennel is recorded in ancient Egypt where it was used in food and medicine. It was also popular in Rome and Greece for its pharmacological properties. Fennel was used as a medicinal herb to prevent bloating, gas digestive issues, and even for the treatment of coughs and chest infections. 

Interest in the phytochemical properties of fennel and its essential oil increased in the 2000s, producing a variety of research studies examining the validity of its traditional use. This article explores the characteristics of fennel essential oil and its therapeutic benefits.

Extraction and Characteristics of Fennel Essential Oil

Fennel essential oil is derived from the seeds of the Foeniculum vulgare plant, a perennial herb belonging to the Apiceae family. The plant is related to other aromatic seed plants such as dill, caraway, and anise. Fennel plants are currently grown in Asia, Europe, and North America. Fennel plants can go up to 2 meters in height and bear small, yellow flowers. The fennel fruit which the oil is extracted from is oblong and is a greenish-yellow color.

The extraction process generally used is steam distillation which yields a clear essential oil with a thin consistency. The aroma of the essential oil is fresh and sweet with a herbal undertone, reminiscent of black licorice. 

Chemical Constituents and Their Therapeutic Effects 

A research study published in the journal Food Research International investigated the chemical constituents found in fennel seed essential oil. The study found that the essential oil consists of nearly 70 to 75 percent trans-anethole, 8 to 14 percent fenchone, and 5 to 9 percent methyl chavicol or estragole. 

Subsequent studies confirmed that trans-anethole is the principal compound in fennel essential oil, but also identified the presence of additional compounds such as limonene.

Trans-anethole has significant therapeutic potential that is validated by research. It exhibits antibacterial, anti-inflammatory, antioxidant, and anti-obesity activity. It is also known to reduce stress and anxiety and may also aid in the improvement of arthritis symptoms. Trans-anethole is found in many other essential oils including anise, camphor, and guarana.

The second most prominent compound in fennel essential oil is fenchone, an ingredient that is used in many therapeutic preparations. Fenchone is known to fight bacterial infections, lower blood pressure, lower blood sugar, and reduce inflammation. It is also used to treat more complex health conditions such as kidney and bladder stones. 

Another component known as methyl chavicol or estragole is also present in the essential oil in noticeable amounts. Methyl chavicol is a phenylpropene that acts as an antiseptic and soothes the digestive system. It also relieves pain and is an antibacterial and antioxidant. 

Sweet Fennel Essential Oil vs. Bitter Fennel Essential Oil

The two varieties of fennel essential oil are derived from the same Foeniculum vulgare plant. Sweet fennel essential oil is of the dulce variety while bitter fennel essential oil is of the vulgare variety. While both of the varieties have similar components, their biological efficacy and composition differ. Sweet fennel essential oil, such as Wholesale Botanics’ fennel oil, contains a considerably higher percentage of trans-anethole, the bioactive component most supported by scientific research. Bitter fennel essential oil contains nearly 20 percent less trans-anethole, reducing its therapeutic efficacy.

On the other hand, sweet fennel essential oil contains a higher percentage of alpha-pinene and limonene, adding to its bioactive potential. For topical use and aromatherapy, sweet fennel essential oil has a stronger therapeutic effect as it contains higher amounts of therapeutically important organic components, making it a preferred choice. 

Therapeutic Benefits of Fennel Essential Oil

Sweet fennel was traditionally used as medicine in many forms, including extracts, tinctures, infusions, and syrups. The medicinal preparations were used to treat several health issues, such as bloating, digestive issues, catarrh, and infantile colic. It was also reported to be used to relieve menstrual pain and symptoms of menopause. The following sections elaborate on the health benefits of fennel essential oil as evidenced by scientific research.

Fennel Essential Oil for Possible Menstrual Pain Relief

Fennel is popularly used as an herbal drug to ease symptoms of dysmenorrhea or painful menstruation. Menstrual pain is treated with anti-inflammatory drugs that inhibit the secretion of prostaglandins, hormones that affect uterine contractions. In long-term use, non-steroidal anti-inflammatory drugs have adverse effects that affect kidney and cardiovascular health. Studies have been conducted in a bid to ascertain the efficacy of fennel essential oil as a gentler and natural alternative to NSAIDs for the relief of menstrual pain.

A 2001 study found that fennel essential oil lowered the strength of menstrual contractions caused by the release of prostaglandin and oxytocin. The study also found that sweet fennel essential oil also reduced the frequency of contractions. Other clinical trials subsequently conducted in later years also confirmed this finding.

To use fennel essential oil for menstrual pain, diffuse fennel essential oil in your surroundings and inhale. You can also add other pain-relieving essential oils to the combination, such as lavender and peppermint.

Fennel Essential Oil for Improving Skin Health

Extracts of fennel have been proven to improve the health and appearance of skin due to their high antioxidant, phenol, and flavonoid content. These chemical constituents work to increase skin cell longevity and deliver an anti-aging effect. Several studies have been conducted to investigate the effect of creams formulated with Foeniculum vulgare extract on human skin.

Results of a 2015 study demonstrated that regular use of creams containing fennel extract for 8 months showed improvement in moisture retention, skin brightening, toning, and acne. In the study, fennel was formulated in a water-in-oil emulsion cream and applied topically to facial skin. At the end of the study, there was a significant reduction in transepidermal water loss (TEWL) and the skin was more moisturized. Researchers also noted that the skin appeared smoother and there were fewer wrinkles.

Another effect that fennel cream had on the skin was reducing hyperpigmentation, redness, and oil production. The flavonoids and linoleic acid present in fennel seeds reduce melanin levels. Specifically, linoleic acid lowers tyrosinase levels in the skin, reducing the rate at which melanin is synthesized.

Apart from this, fennel essential oil also has the potential to be used as an acne-clearing agent. It reduces the production of sebum in the skin, and also has antiseptic and antibacterial properties. The sebum-reducing mechanism is attributed to the presence of linolenic, linoleic, and oleic acid in the essential oil, compounds which inhibit the sebum-producing enzyme 5-reductase.

To improve skin appearance, reduce dullness, minimize fine lines, and alleviate symptoms of sun damage, you can incorporate fennel essential oil into your skincare regimen. Add fennel essential oil to your moisturizer and use it as normal. You can also create your own facial oil by combining a few drops of fennel essential oil with a carrier oil such as rosehip or jojoba.

Fennel Essential Oil for Potentially Aiding Wound Healing

Wound healing is a simple, self-regulating process that generally does not require much mediation. However, home remedies using agents, such as fennel essential oil, can speed up the process and prevent complications such as scabbing and scarring. Fennel essential oil is antibacterial and antiseptic, properties that can prevent the wound from becoming infected and encourage healing.

A study conducted in 2020 found that fennel essential oil not only reduced bacterial growth, but also prevented the formation of bacterial biofilm, an organic layer that provides protection to the bacteria growing on wound surfaces.

To use fennel essential oil for the treatment of wounds, dilute it with a carrier oil or in a cream formulation and apply it to the wound. Do not apply undiluted essential oil directly to an open wound; it may cause an adverse reaction and complicate healing. 

Fennel Essential Oil for Potentially Improving Cardiovascular Health 

Fennel has been extensively studied for its effects on cholesterol and heart health. Two active components, namely anethole and methanol, are responsible for the anti-atherogenic and anti-cholesterol effects. 

A study tested how fennel extract impacted the blood of guinea pigs. Results demonstrated that the compound anethole in fennel seeds can prevent platelets from sticking together, reducing the chances of blood clots. Anethole may also help break up any existing blood clots, improving vascular health and blood flow.

Another research published in the Arabian Journal of Chemistry confirmed that fennel extract may help lower the amount of lipids in the bloodstream. This, in turn, lowers cholesterol and prevents fatty deposits from accumulating in the blood vessels. 

To potentially improve heart health, you can incorporate fennel essential oil into your aromatherapy routine. Add fennel essential oil to your diffuser and inhale the beneficial bioactive components present in the oil. 

Precautions for Using Fennel Essential Oil

While fennel is used quite commonly in food, herbal tea, and as medicine, there are precautions that need to be taken before its use. Fennel essential oil should never be ingested, even when diluted. 

Additionally, the topical use or inhalation of fennel essential oil may trigger an allergic reaction. If you are allergic to mugwort or carrot, then you may be likely to be allergic to fennel as well. Always patch test fennel essential oil before using it topically to avoid adverse reactions.

For pregnant or breastfeeding women, the use of fennel essential oil in any application is not advisable. Fennel has estrogenic effects which may affect pregnancy term and fetus development. A study conducted in 2004 found that fennel essential oil had a toxic effect on fetus cells, making it unsuitable for use by pregnant women. 

If you suffer from bleeding disorders or blood thinning, be wary of using fennel essential oil. When inhaled or even when used topically, it may cause bruising or excessive bleeding. 

Before incorporating fennel essential oil into your routine for curative purposes, it is best to seek advice from a medical professional. 

Final Notes on Fennel Essential Oil Benefits

Fennel essential oil is a versatile essential oil that can be used for purposes ranging from enhancing skin appearance to improving heart health. Its anise-like scent makes it pleasant to diffuse in the room or apply topically onto the skin. 

To enhance the aromatic experience of fennel essential oil, you can create a blend with geranium and citrus essential oils. Geranium essential oil has a gentle, rosy scent that can add complexity to the sweet notes in fennel. Adding citrus essential oils, such as lemon and grapefruit, will add a brightness and freshness to the overall scent, balancing the spicy notes in fennel essential oil .