Star anise essential oil: the liquorice scent of Christmas and who should avoid it

Star anise smells like liquorice and mulled wine. The oil, however, is almost pure anethole, and so it comes with clear rules on dilution, pregnancy and children.

In brief: Star anise essential oil (Illicium verum) is three quarters to nine tenths trans-anethole, which is why it smells like liquorice. In a diffuser 1–2 drops, on the skin at most 1.75%. It is not for pregnant or breastfeeding women, children under 6, or people with oestrogen-sensitive tumours.

Latin name	Illicium verum, Chinese star anise
Plant part and extraction	star-shaped fruits, steam distillation (our oil: India, BIO)
Main components	trans-anethole 72–92%, estragole and limonene around 2%
Scent	sweet, liquorice-like, spicy
On the skin	max. 1.75%; we recommend up to 1%: 2 drops per 10 ml, 6 drops per 30 ml
Safety	not for pregnancy, breastfeeding, children under 6, endometriosis

Star anise is those brown little stars from mulled wine and Christmas tea. Its essential oil smells sweetly of liquorice, but with a warmer, spicier note than aniseed. In a diffuser it complements orange and cinnamon beautifully, and thanks to it a Christmas scent gains a "patisserie" dimension.

The oil is, however, almost a single pure substance, trans-anethole. That is the reason star anise comes with clearly defined rules: at what dilution, for whom not, and why not to keep the bottle for years.

Star anise, aniseed and fennel: the same scent, similar rules

Three different plants, one main substance. That is why they also have similar safety restrictions:

Oil	Plant	Trans-anethole	Character of the scent
star anise	Illicium verum, a tree from southern China and Vietnam	72–92%	liquorice, warmer, spicy
aniseed	Pimpinella anisum, an herb of the carrot family	roughly 75–96%	liquorice, sweeter, herbal
fennel	Foeniculum vulgare, an herb of the carrot family	predominates, less than in aniseed	liquorice with a green, herbal trace

The practical consequence: put only one of these oils in a single blend. If you combine star anise with aniseed, the doses of anethole add up.

True and Japanese star anise

True star anise (Illicium verum) has a poisonous relative, Japanese star anise (Illicium anisatum). It contains anisatin and other neurotoxic substances, and there have been cases of mix-ups in the spice. The review by Sharafan et al. (2022) states that the seeds of I. anisatum are highly toxic.

For the essential oil this means just one thing: buy oil with the Latin name Illicium verum stated, from a supplier who states it. The oil should never go in the mouth anyway, nor into tea.

Scent and what to blend star anise with

Star anise is distinctive and easily dominates in a diffuser. In a blend, use it in a minority proportion:

orange and mandarin: the most natural partners,
cinnamon and clove: the scent of mulled wine,
fir: liquorice and conifer needles, a winter forest,
frankincense or cedar: a deeper, resinous base.

Diffuser and oil burner: how many drops

For a diffuser, put 1–2 drops of star anise per 100 ml of water and add 2–3 drops of citrus.
For an oil burner, 1 drop of star anise with 2 drops of orange is enough.
Leave the scent for 30–60 minutes, then switch off and ventilate.
Do not use star anise in a room where there is a pregnant or breastfeeding woman, a small child or a cat.

General dosing by room size can be found in the article how many drops for a diffuser and oil burner.

Blends with star anise for autumn and Christmas

Mulled wine (diffuser, 100 ml): 1 drop of star anise, 3 drops of orange, 1 drop of cinnamon.
Winter forest with liquorice (diffuser): 1 drop of star anise, 2 drops of fir, 1 drop of cedar.
Mandarin biscuits (oil burner): 1 drop of star anise, 2 drops of mandarin, 1 drop of cardamom.

More festive combinations are in the overview of Christmas scents for the diffuser, and autumn and winter tips in the article aromatherapy during winter.

On the skin only a little, and only adults

Tisserand and Young recommend at most 1.75% on the skin for star anise oil. At home you do not need to go to the limit; for a warming massage 1% is enough: 2 drops per 10 ml or 6 drops per 30 ml of a carrier oil, for example jojoba. For a bath only 1–2 drops mixed into a spoonful of carrier oil or milk.

The age of the oil is important. Anethole oxidises in air, and an oxidised oil may sensitise the skin. Do not use old star anise that smells "sour" or has thickened on the skin.

Why anethole imposes limits on who may use star anise

At high concentrations, trans-anethole shows weak oestrogenic activity in laboratory tests. The European Medicines Agency, in its assessment report on aniseed, points out that with long-term or excessive use it may affect hormonal treatment, including contraception. Tisserand and Young therefore give the following restrictions for oils rich in anethole:

pregnancy and breastfeeding: do not use, even in a diffuser,
endometriosis and oestrogen-dependent tumours: do not use,
children: Tisserand and Young say under 5 years, we hold the limit at 6 years; for older children only in a diffuser and exceptionally (essential oils and children),
blood-thinning medicines: anethole may affect clotting, so do not use it on the skin in that case.

Cats: in a room with a cat that cannot leave, do not run a diffuser (essential oils and pets).

Traditional use

Star anise has been used for centuries in Chinese cooking and traditional care, in Europe mainly as a Christmas spice. Shikimic acid is obtained industrially from star anise, the starting material for the production of the antiviral oseltamivir. That does not mean, however, that the oil or the spice acts against flu. Our oil is intended for aromatherapy and external use.

Frequently asked questions

What does star anise essential oil smell like?

Sweetly of liquorice, similar to aniseed, but warmer and spicier. In a blend with orange and cinnamon it recalls mulled wine.

Can I use star anise oil during pregnancy?

No. Because of its high anethole content, Tisserand and Young do not recommend it during pregnancy and breastfeeding, even in a diffuser.

What is the difference between star anise and aniseed?

They are two unrelated plants: star anise is a tree, aniseed an herb of the carrot family. The oils, however, share the main substance, trans-anethole, and smell similar. Aniseed is sweeter and more herbal, star anise spicier.

How many drops of star anise for a diffuser?

1–2 drops per 100 ml of water, ideally with citrus. More star anise will not improve the scent; the liquorice then overpowers everything else.

How long does star anise oil last?

Once opened, it is better to use it up within a year and store it cool and dark. Anethole oxidises, and old oil irritates the skin more than fresh.

Sources

Sharafan M. et al.: Illicium verum (Star Anise) and Trans-Anethole as Valuable Raw Materials for Medicinal and Cosmetic Applications, Molecules 2022 – PMC8839413
EMA/HMPC: Assessment report on Pimpinella anisum L., fructus and aetheroleum (oestrogenic activity of anethole, interactions) – PDF
Tisserand R., Young R.: Essential Oil Safety, 2nd edition, Churchill Livingstone 2014 (Star anise profile).
AromaWeb: Star Anise Essential Oil, safety information – aromaweb.com

Updated: 27 September 2026

Author: Jana Vránová, the editorial pen name of the Pěstík.cz team. She writes about the garden, herbs and essential oils. We take safety and dosage information from specialist literature and official sources, which we cite in every article.