RUŌOD Lab

Sweet Fennel Oil

Essential oil · Aromatic / Green

anise, sweet, herbal, green — top to heart note.

Aroma illustration for Sweet Fennel Oil: small ridged seeds, star anise and a sprig of herbs, for its fennel, anise and herbal notes. It illustrates smell associations, not the material or its source.Illustration of pale green, ridged fennel seeds. Sweet fennel oil is distilled from the seeds.
Aroma View: an illustration of what Sweet Fennel Oil smells like (fennel, anise, herbal), drawn by RUŌOD Lab — not its appearance or its source.An original illustration of the botanical source by RUŌOD Lab — not a photograph of the material.
Images

By the RUŌOD Lab TeamRevision 1Updated

In short

Sweet fennel oil is distilled from the seeds of Foeniculum vulgare var. dulce. It is rich in anethole and has a sweet anise odour with a fresh herbal edge.

What Sweet Fennel Oil smells like

Sweet fennel oil is dominated by trans-anethole, but a glossary finds it greener and more herbal than anise, with a cool, camphor-like edge from fenchone — a slightly bitter ketone it names as the clearest chemical marker separating fennel from anise and star anise. Bitter fennel carries more of it. A forum perfumer describes fennel as anise-like but shifted, definitely more green. Fennel also contains estragole, which IFRA restricts.

Leading note
Green anise
Clear facets
Sweet
Supporting facets
Herbal, green, camphoraceous
Faint facets
Earthy
Character
Fresh, sweet, herbal
  • anise
  • sweet
  • herbal
  • green

What makes Sweet Fennel Oil distinctive

Anise with a green, camphor-cool edge — fenchone is what turns the sweetness herbal.

Where the descriptions disagree: The claim that anise and star anise contain essentially no fenchone comes from a single glossary.

How Sweet Fennel Oil is used

Used in herbal, fougère and fresh-spicy compositions, and in flavours.

Typical role: modifier (used in small amounts to change the character of a blend).

How Sweet Fennel Oil differs from similar materials

Star Anise Oil
Star anise is the purer, sweeter anise; fennel is greener and more herbal, with a cool camphor edge from fenchone.
Anethole
Anethole is the oil's main constituent alone, sweet anise; fennel adds fenchone's green, camphoraceous edge.
Tarragon Oil
Tarragon is estragole-led, greener, with celery; fennel is anethole-led, sweeter, with fenchone's camphor edge.
Fenchone
Fenchone gives fennel its cool, camphor-like edge; alone it is warm, earthy and bitter.

An asterisk marks a difference that a cited source states directly. The others compare the published descriptions of each material. Smell varies with grade, supplier and dilution; compare them side by side on blotters before substituting one for another.

Formulation considerations

Bitter fennel oil contains more fenchone and smells sharper; record which you have.

Identity and classification

Type
Essential oil
Origin
Natural
Odour family
Aromatic / Green
Note position
Top to heart note
Physical form at room temperature
Liquid
Also known as
Fennel seed oil
Botanical source
Foeniculum vulgare
CAS number
8006-84-6

The CAS number was checked on 19 October 2026 against a PubChem substance record that gives it for this material. A natural material is a mixture, so it has no single formula; its composition varies with origin and processing.

Safety and compliance

This page is general information, not a safety assessment or a specification. Confirm identity, composition, IFRA status and allergen content from your supplier's documents for the lot you hold.

Materials it works with

  • Anethole

    Aroma chemical · Aromatic / Spicy — anise, licorice, sweet, herbal

  • Star Anise Oil

    Essential oil · Aromatic / Spicy — anise, licorice, sweet, spicy

  • Fenchone

    Aroma chemical · Aromatic / Woody — camphoraceous, herbal, fennel, earthy

  • Lavender Oil

    Essential oil · Aromatic / Floral — lavender, herbal, floral, fresh

Sweet Fennel Oil is also suggested as a partner on the pages for Anise Oil and Dihydroanethole.

Used in formulas and accords

Used in 2 published formulas

Sweet Fennel Oil is an ingredient in 2 perfume formulas in the Formula & Accord Library.

RUŌOD House Originals

Original compositions by RUŌOD House.

Further reading

Questions about Sweet Fennel Oil

Is Sweet Fennel Oil natural or synthetic?

Sweet Fennel Oil is natural. It is a volatile oil obtained from plant material by steam distillation or, for citrus peels, by cold expression.

What is the CAS number of Sweet Fennel Oil?

8006-84-6, the registry number for the essential oil as a substance rather than a single molecule. It was checked against PubChem on 19 October 2026.

Which published formulas use Sweet Fennel Oil?

Sweet Fennel Oil is used in 2 published formulas in the RUŌOD Lab Formula & Accord Library: Anise Ink and Myrrh Lantern. Each is listed with a link under "Used in formulas and accords" on this page.

Sources

  • PubChem — substance 439398637, checked 19 October 2026.
  • Premiere Peau — Fennel — published perfumery reference.
  • Basenotes — I discovered anise (forum) — published perfumery reference.
  • Olfactory profile: the RUŌOD Lab team's synthesis of the published descriptions above, reviewed 21 October 2026. Evidence: more than one published description. Classification and the short description: revision 1. Descriptions of odour are judgement, not measurement.

Your own records, next to the reference

Keep your own record of Sweet Fennel Oil — supplier, cost, stock, dilutions and where it is used — in RUŌOD Lab's material library.

The material library All materials