Rosemary oil for hair

A rosemary hair oil is rosemary essential oil diluted in a carrier oil, massaged into the scalp and then washed out. This guide uses 2%, the Tisserand Institute's usual strength for body oils, because no source gives a figure for the scalp alone. Here is how to use rosemary oil for hair: how many drops, which carrier, how to patch test, and how to wash it out.

Drops of rosemary oil for a scalp oil, by the size of the bottle. Strengths from the Tisserand Institute's range for body oils. Drops are approximate: this counts 30 to the millilitre, as their chart does, rounded down.
Strength	10 mL	30 mL	50 mL	100 mL
2%	6	18	30	60
1%, for sensitive skin	3	9	15	30

Neat oil on the scalp

Never put rosemary essential oil straight on the scalp. Dilute it in a carrier oil first. The Tisserand Institute's range for body oils is 1 to 3%, and the mixer above starts at 2%. Choose 1% if your skin is sensitive. When you apply it, part your hair and massage a little of the diluted oil into the scalp.

There is no published figure for the scalp alone that we could find, so this page uses the body range, and says so.

The carrier

The carrier is most of the bottle, so it decides how the oil feels in your hand.

Sweet almond: Thin and pale, and pours easily.
Jojoba: Thin and golden, with almost no smell.
Argan: Light, with a faint nutty smell.
Coconut: Solid when the room is cool, and melts in your hands.
Castor: Thick and slow to pour. For a rosemary and castor oil that spreads more easily, mix the castor half and half with a lighter carrier.

A patch test

Skin can react to an essential oil, which is why the test comes before the first use.

Mix your blend first. Test the diluted oil, never the neat oil.
Wash a small patch of your forearm with unscented soap, and pat it dry.
Rub in a few drops of the blend, and cover it with gauze.
Wait 24 hours, then look. If the skin has reacted, do not use the blend.

Method from Healthline's medically reviewed guide to essential oil safety, updated August 2024.

How long, and how often

We have found no source that gives a time to leave it on, or a number of times a week, so we do not give one.

Oil washes out best when shampoo goes on before water. Work shampoo into dry hair, then wet it, rinse, and shampoo again.

Hair that feels greasy

If a rosemary hair oil leaves your hair feeling greasy, use less of the blend, or a thinner carrier such as almond. Shampoo twice, the first time on dry hair, and use conditioner only after the second.

Questions

Questions about rosemary oil for hair

Can we apply rosemary oil directly on hair?: No. Dilute it in a carrier oil first, at the strengths in neat oil on the scalp above, and patch test before the first use.
How long do you leave rosemary oil on your hair?: We do not give a time, for the reason in how long, and how often. When you wash it out, put shampoo on dry hair first, then wet it and rinse.
What happens if I put rosemary oil on my hair every day?: No daily limit is published that we know of. Keep to Essentially's own safety lines: dilute it, try a small patch first, and keep it away from eyes. If your skin reacts, stop, as the patch test method says.
What is the disadvantage of rosemary oil for hair?: It is an essential oil, so it has to be diluted and kept away from the eyes, and too much carrier can leave hair greasy. The section on hair that feels greasy has the fix.
Why does my hair fall out after using rosemary oil?: We sell this oil, so we are not the people to answer a medical question. If your hair or scalp changes in a way that worries you, stop using it and ask a doctor or pharmacist.
Does rosemary oil help in hair growth?: We make no claim that it does. We sell the oil, so that is a medical question for a doctor or pharmacist. This page tells you how people use it, and nothing more.

The rest of the guide

Rosemary oil
What it is, how to read its label, and the mixer for a body oil, bath or diffuser.
How to use rosemary oil
A diffuser, a bath, a body oil, the house, and what it blends with.
How to make rosemary oil
Infusing dried rosemary in a carrier at home, step by step.

Rosemary oil, 10 mL, $21.95, from Essentially