Ajowan essential oil: thymol from the seeds, dilution and use at home

Ajowan smells like a strong thyme with spice. What kind of oil it is, how to dilute it and where it comes in handy at home.

In brief: Ajowan is an essential oil from the seeds of the Indian spice ajwain (Trachyspermum ammi). It smells like a strong thyme with a spicy edge, because its main component is thymol. On the skin at most 1% (2 drops per 10 ml), in a diffuser 1 drop in a blend. Not for children, pregnant women or a room with a cat.

Latin name	Trachyspermum ammi (syn. Carum copticum), ajwain
Plant part and extraction	seeds (fruits), steam distillation (our oil: India, BIO)
Main components	thymol roughly 34–66%, also p-cymene, γ-terpinene, carvacrol
Scent	sharp, spicy, thyme-like with an aniseed note
Dilution on the skin	max. 1%: 2 drops per 10 ml, 6 drops per 30 ml
Safety	irritant phenolic oil

Ajowan (also spelt ajwain or ajvain) is little known in the Czech Republic, but in Indian cooking it is part of the basic kit. The tiny grey-brown seeds are fried in ghee and added to pulses and flatbreads. The essential oil from them is clear to brownish and smells so distinctly that many people mistake it for thyme the first time.

The similarity is no accident: both ajowan and thyme contain a lot of thymol. That makes it a strong oil for cleaning and spicy blends, but also an oil that must be handled carefully on the skin. Below is a practical guide to using it at home.

What is in ajowan oil

The composition of ajowan depends a great deal on the variety and growing conditions. An Iranian study of ten populations found thymol from 34% to 66%, alongside carvacrol, p-cymene and γ-terpinene. In drought the plants produced more thymol. Other analyses report thymol even at around 89%. For home use this means only one thing: treat ajowan as an oil with a high proportion of phenols, just like thyme and oregano.

	Ajowan	Thyme	Oregano
Made from	seeds	flowering herb	flowering herb
Main phenol	thymol	thymol	carvacrol
Scent	spicy, thyme-like, slightly aniseed	sharply herbal	warm, peppery
Max. on the skin	1%	1%	0.5–1%

Scent and combinations

Ajowan is sharper and more "kitchen-like" than thyme. In the first second it recalls thyme tea, then pepper comes through, with a lightly sweet, aniseed note from the seeds. On its own it is heavy; in a blend it adds warmth and depth:

with ginger and orange for a warming winter scent,
with lemon and tea tree for cleaning,
with rosemary and lavender for a herbal massage blend,
with coriander for a spicy "Indian" scent in an oil burner.

How to use ajowan at home

Use	Dose for adults	Note
Diffuser	1 drop of ajowan + 2–3 drops of other oils per 100 ml of water	30 minutes, then ventilate
Oil burner	1 drop of ajowan in a blend	kitchen, hallway, workshop
Massage	max. 1%: 2 drops per 10 ml, 6 drops per 30 ml	back, shoulders, calves; not the face
Bath	max. 1–2 drops in a spoonful of carrier oil	adults only, better to leave out with sensitive skin
Cleaning	5 drops in 300 ml of a water and vinegar solution	gloves, shake well

An overview of drops for rooms of different sizes is in the article how many drops for a diffuser and oil burner.

Three recipes

Winter kitchen (diffuser): 1 drop of ajowan, 2 drops of orange, 1 drop of ginger.
Indian oil burner: 1 drop of ajowan, 2 drops of coriander, 1 drop of lemon.
Warming back massage after gardening (30 ml carrier oil, 1.5% in total): 3 drops of ajowan, 3 drops of ginger, 3 drops of lavender. Ajowan makes up 0.5%.

Method: cleaning spray with ajowan

Pour 250 ml of water and 50 ml of vinegar into a 500 ml spray bottle.
Add 5 drops of ajowan and 5 drops of lemon (or tea tree).
Shake thoroughly before each use; the oil does not mix with water.
Spray onto a worktop, sink or bin, leave for a while and wipe off.
Do not use on marble, natural stone or waxed wood. Use the spray up within a month.

More recipes for homemade cleaning products can be found in the article on natural cleaning with essential oils.

Tradition and research

Ajwain seeds are traditionally used in India and Iran in cooking and in Ayurveda, mainly for digestive complaints and colds, usually as a spice or a decoction, not as a concentrated oil. The Ayurvedic background of essential oils is described in the article Indian aromatherapy.

In laboratory studies, ajowan oil and thymol inhibit the growth of bacteria, moulds and pests. That explains why ajowan suits cleaning blends well, but it says nothing about treating people. Our oil is intended for aromatherapy and external use, not for internal use. A spice in food and an essential oil are in dose and effect entirely different categories.

Safety

Skin: never undiluted, max. 1%. Thymol irritates and may lead to sensitisation, especially with old, oxidised oil.
Eyes and mucous membranes: do not drip into the nose or mouth or use for inhalation over a pot; the vapours irritate the eyes.
Children: never on the skin, and not in a diffuser in a room with children under 6. Safer choices for children are in the article essential oils and children.
Pregnancy and breastfeeding: do not use.
Cats: they break down phenols very slowly, so do not diffuse ajowan in their space. More in the article essential oils and pets.
Storage: dark glass, cool, tightly closed. Use up an opened bottle within 2 years.

What to look for when buying

The label should state the Latin name Trachyspermum ammi (or the older Carum copticum), the plant part (seeds) and the country of origin. Ajowan is sometimes confused with "thymol oil" from other plants, or diluted. A reputable supplier will state the thymol content of the batch on request. If the oil smells like pure thyme without any spicy depth, ask about its origin.

Frequently asked questions

What is ajowan and how does it differ from caraway?

Ajowan (ajwain) is an Indian spice from the plant Trachyspermum ammi, related to caraway and coriander. The seeds look similar to caraway, but they smell and taste like strong thyme, because they contain thymol.

Is ajowan oil the same as thyme oil?

No, it is a different plant and the oil is distilled from the seeds. The main component, thymol, is shared, however, which is why you dilute both oils the same way: at most 1% on the skin.

Can I take ajowan oil internally for digestion?

Not our essential oil. It is intended for external use and aromatherapy. For the kitchen and for tea, use the spice seeds, not the concentrated oil.

How many drops of ajowan should go in a diffuser?

One drop in a blend with 2–3 drops of milder oils per 100 ml of water. Let the diffuser run for 30 minutes and ventilate.

Is ajowan suitable for children?

No. Not on children's skin at all, and do not use it in a diffuser where children under 6 spend time. It contains irritant thymol.

Sources

Nano Silicon Modulates Chemical Composition and Antioxidant Capacities of Ajowan (Trachyspermum ammi) Under Water Deficit Condition, Foods 2025 – PMC11719498
Probing the responses of thirty-six ajwain ecotypes under drought stress, BMC Plant Biology 2025 – PMC12838511
Sanei-Dehkordi A. et al., analysis of Trachyspermum ammi oil (thymol 88.95%), 2024 – PubMed 39237741
Tisserand Institute: Essential oil safety for cats – tisserandinstitute.org
Tisserand R., Young R.: Essential Oil Safety, 2nd edition, Churchill Livingstone 2014.

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.