Fennel

What Is Fennel in Skincare?

Fennel (Foeniculum vulgare) is a sweet, licorice-scented herb whose seeds are used in skincare in two forms: a water- or glycerin-based seed extract used in toners, gels, and creams, and a steam-distilled essential oil used in small amounts for fragrance. Fennel extract is valued as a light, refreshing botanical with antioxidant compounds, and it shows up most often in products for oily and combination skin.

EWG Skin Deep rating for fennel

The two forms are used very differently. The extract is a gentle supporting ingredient, while the essential oil is potent and strictly limited by fragrance safety standards.

Fennel Quick Facts

How Fennel Works on the Skin

Fennel extract contains polyphenol antioxidants that help protect the look of skin from environmental stress, and it gives toners and gels a fresh, clean feel. It is popular in products for oily skin because it is light and leaves no residue.

The best study we found was in people. In a study, a water-in-oil cream containing 4% concentrated fennel extract was compared with the same cream without extract. The fennel cream significantly improved measured skin moisture and transepidermal water loss, while the plain base did not, and surface measures of roughness, scaliness, smoothness, and wrinkles changed significantly as well (Rasul et al., 2012). The paper reports these as instrument readings on volunteers' skin, and it does not test fennel against other botanicals.

Older versions of this page described fennel as a diuretic for cellulite, a source of zinc that rebuilds skin structures, and a way to remove toxins and dark circles. Those claims are not supported for a cosmetic and have been removed.

How to Use Fennel in Formulas

• Extract rate: Use the highest rate on your supplier's data sheet. The published cream study used 4% concentrated extract.
• When to add the extract: Add to the water phase at cool-down, below 40°C (104°F).
• Essential oil limit: Fennel oil contains estragole, which IFRA restricts. Under IFRA Amendment 49, the estragole limit is 0.0062% for Category 5B and 0.075% for Category 5A. Using IFRA's indicative 3% estragole content for sweet fennel oil, a 0.0062% estragole limit works out to roughly 0.2% sweet fennel oil. Check the IFRA category for your product type and your oil's certificate of analysis.
• Base: A fennel toner or gel works well in an aloe gel base.
• Preservation: Water-based fennel products need a broad-spectrum preservative. A homemade fennel seed tea used as a toner has none, so refrigerate it and throw it out after 2 to 3 days.
• Storage: Keep extract and oil tightly closed, cool, and away from light.

Who Fennel Suits

Fennel extract suits normal, oily, and combination skin and is generally gentle. The essential oil is best kept to rinse-off and body products at very low levels.

Sensitive skin: Patch test on the inner arm and wait 24 hours, and start at the lowest rate on your supplier's range. Anyone with a known allergy to fennel or anise should avoid it. If you are pregnant or breastfeeding, skip fennel essential oil and ask your healthcare provider before using fennel products.

Frequently Asked Questions

Is fennel good for your face?

Fennel extract is a gentle, refreshing antioxidant botanical that suits most skin types, especially oily and combination skin. In a study, a cream with 4% fennel extract measurably improved skin moisture compared with the plain cream.

Can fennel tighten pores?

No ingredient changes pore size permanently. A cool fennel toner can make skin feel refreshed and look less shiny for a while, which can make pores look less noticeable. See our large pores glossary entry for more.

How do you make a fennel seed toner?

Steep 1 tablespoon of crushed fennel seeds in 1 cup of just-boiled distilled water for 15 minutes, strain, and cool. It has no preservative, so keep it in the refrigerator and use it within 2 to 3 days.

Is fennel essential oil safe on skin?

Only in small amounts. Fennel oil contains estragole, which IFRA limits in leave-on products, so a face cream can hold only about 0.2% sweet fennel oil. Never apply it undiluted.

Does fennel brighten skin?

Fennel extract is sometimes listed among botanicals for a brighter look, but we did not find a human study showing a measurable change in skin tone. For brightening, choose an ingredient with stronger evidence, such as vitamin C.

Can I use fennel during pregnancy?

Avoid fennel essential oil during pregnancy and breastfeeding. For fennel extract in a finished product, ask your healthcare provider first.

Shop and Learn More

The product previously featured in this collection has been discontinued. To make your own fennel toner gel, add a preserved fennel extract to our Aloe Vera Gel Serum Base. For more ideas for oily skin, read Natural Oily Skin Cleanser: 6 Homemade Face Wash Recipes, and see our licorice glossary entry.

Sources

• Rasul A, Akhtar N, Khan BA, Mahmood T, Uz Zaman S, Khan HMS. Formulation development of a cream containing fennel extract: in vivo evaluation for anti-aging effects. Pharmazie. 2012;67(1):54-58. doi:10.1691/ph.2012.1083
• International Fragrance Association (IFRA). IFRA Standard: Estragole, Amendment 49 (2020), including Annex I estragole levels in fennel oils.

These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.

About the Author
Written by Kari Thomas, cosmetic formulator and founder of Skin Perfection.