Castor oil for eyelashes and eyebrows: how to use it and what to expect
- Castor oil for eyelashes: no published study shows that it makes lashes grow. It coats each hair, leaving it more supple and glossier.
- The technique: less than a drop on the wand, in the evening on make-up-free lashes, never along the eyelid margin, 1 to 3 evenings a week to begin with.
- The timeline: gloss from the first application, less breakage over 4 to 8 weeks, nothing on density before a full lash cycle (4 to 11 months).
- Before you start: a 48-hour patch test on the inner elbow, contact lenses out, nothing on an irritated eye or on lash extensions.
You searched for "castor oil for eyelashes" because a bottle is waiting in the bathroom cabinet, or because you are hesitating in front of a shelf. Here is the technique with quantities, a timeline based on the lash cycle, the precautions, and a straight answer on whether it does anything for length.
- Does castor oil really make eyelashes grow?
- How do you use castor oil for eyelashes?
- Castor oil for eyebrows: do you need to change the technique?
- How long does it take for castor oil to grow eyelashes?
- What are the downsides of castor oil?
- Castor oil or lash serum: what the label tells you
- Castor oil for eyelashes: which oil to choose, and which applicator?
- Before you start
Does castor oil really make eyelashes grow?
No published study shows that castor oil makes eyelashes grow, lengthens them or makes them more numerous. It coats the shaft of each lash, leaving it more supple and glossier.
A systematic review of 22 articles found only weak evidence for shine and no strong evidence for hair growth. The 2023 TFOS Lifestyle report describes castor oil as a lash conditioner, with no research at all on the follicle. Ricinoleic acid, around 90% of the oil, resembles prostaglandin E1, but the 2007 CIR report states that it does not share its properties.
That is why you will not read "strengthens" or "stimulates" here: the EU regulation on cosmetic claims requires adequate evidence and forbids going beyond the effects that have been demonstrated.
How do you use castor oil for eyelashes?
To use castor oil for eyelashes, put less than a drop on the wand along the base of make-up-free lashes, in the evening, 1 to 3 times a week, without touching the eyelid margin.
The technique in 5 steps
- Remove your make-up and dry the lashes.
- Pick up less than a drop with the wand supplied with the castor oil, wiping the excess on the neck of the bottle.
- Apply from base to tip, eye closed, on the lash and not on the eyelid margin: cosmetics applied along the lid edge migrate into the tear film.
- Spread it with a clean spoolie, in a single pass.
- In the morning, remove the excess with warm water or make-up remover.
Frequency: 1 to 3 evenings a week for 4 to 8 weeks, then adjust. Nightly use is not a rule: the only tolerance data, a 2021 randomised trial, covers 4 weeks of twice-daily application on the eyelids in 26 participants, with no adverse events reported.
Cut the castor oil half and half with jojoba oil if it feels too thick. For hair, the protocol is different: see our guide to a castor oil hair mask.
Castor oil for eyebrows: do you need to change the technique?
On the eyebrows, castor oil is brushed through in the direction the hairs lie, on clean skin, with the same quantity (less than a drop) and the same frequency as on the lashes.
The hair is coarser and the area wider: the brush supplied replaces the wand, working from the inner end outwards. An eyebrow sits on exposed skin: blot the excess with a tissue, and apply nothing to an area that has been plucked or waxed the same day, or that is irritated.
The same technique applies to sparse brows on men, without expecting any new density. If you already use this oil for your beard, its detailed composition is described there.
How long does it take for castor oil to grow eyelashes?
Castor oil changes the look of eyelashes from the first application (coating, gloss), but a lash gains 0.12 to 0.14 mm a day and its full cycle lasts 4 to 11 months: any judgement on length or density before several months is premature.
Those figures come from a 2018 optometry review (the active phase, known as anagen, lasts 4 to 10 weeks). A lash that falls out is replaced on its own, and many "before and after" photos show that renewal; the oil sits on the shaft that has already emerged, not on the follicle.
| When | What you may notice | What it proves |
|---|---|---|
| Day 1 | Lashes more supple, glossier, coated | A cosmetic effect, gone once you remove your make-up |
| Weeks 6 to 8 | Fewer broken lashes on the mascara wand | Compare against your reference photo |
| Months 4 to 11 | One full cycle has passed | No study has measured a change in density |
Castor oil on lashes, before and after: take your own reference photo
We have no photos and no testimonials, and we will not invent any. Take your own, on day 1 and in week 8, same light, same angle, eye closed: compare gloss and broken lashes, not length.
What are the downsides of castor oil?
The downsides of castor oil on eyelashes come down to four points: it must not get into the eye, it can occasionally cause an allergy, it is thick and greasy, and it keeps for 18 to 24 months after opening.
The documented dangers concern the seed, whose ricin does not pass into the pressed oil, and the eye: the CIR report cites changes to the corneal epithelium in 100 patients after instillation, and the TFOS report a transient discomfort on contact with the eye. On the eyelid and the lash, yes; in the eye, no. If it gets in, rinse with clean water and see your GP or an optician if the discomfort persists.
Allergy is rare but documented in a 2024 review of contact dermatitis from lip products: hence the 48-hour patch test.
Texture: with a viscosity of around 890 centistokes, too much oil glues the lashes together and leaves the eyelid greasy.
Storage: away from light and heat, for 18 to 24 months after opening, the period that the EU cosmetics regulation requires on the label. If the smell turns, throw the oil away.
Castor oil or lash serum: what the label tells you
Of 79 lash serums analysed in a 2026 French study, around 30% contain a prostaglandin analogue; the rest are formulated with ingredients such as castor oil.
In December 2025, an ANSES alert from the French health agency described, after a serum containing isopropyl cloprostenate, a darkened iris and a loss of the fat around the eye, both irreversible. In February 2026, the EU's scientific committee concluded in its SCCS opinion that none of the three analogues assessed should be used in a cosmetic for eyelashes or eyebrows.
Castor oil is a fatty substance with no pharmacological action on the follicle, according to the CIR assessment: that is why it makes no promise of longer lashes, and why this article does not write "strengthens" or "stimulates".
| What you read | What it is | What it means |
|---|---|---|
| Ricinus Communis Seed Oil, alone or first on the list | A "skin conditioning" agent according to CosIng and COSMILE Europe | Coating and gloss, nothing on the follicle |
| Isopropyl Cloprostenate, Ethyl Tafluprostamide (DDDE), Methylamido-Dihydro-Noralfaprostal (MDN) | Prostaglandin analogues | Named in the ANSES alert and the SCCS opinion |
| Bimatoprost | The active ingredient of a prescription medicine | No place in a cosmetic |
Castor oil for eyelashes: which oil to choose, and which applicator?
For eyelashes, choose a castor oil that is 100% pure, virgin and cold pressed, certified organic, in a glass bottle, sold with a wand or a brush. A single name on the label rules out any prostaglandin analogue, glass protects the oil from light, and "less than a drop" can only be measured with a wand.
Our organic plant oils set castor oil alongside jojoba, black seed and rosehip.
Before you start
Eight precautions that most pages leave out.
- Patch test: a trace of oil on the inner elbow, a 48-hour wait, no redness.
- Never in the eye or along the eyelid margin; if it gets in, rinse with clean water.
- Not on an irritated eye, nor after an eye infection or eye surgery: wait for advice from your GP or eye specialist.
- Contact lenses: out before you apply the oil, back in the next morning after rinsing.
- Lash extensions: the adhesive does not tolerate oils, and the TFOS report lists these adhesives among the products that pose a risk to the eye. Wait until they have been removed.
- Pregnancy and breastfeeding: no known restriction for external use; ask a health professional for advice.
- Children: no castor oil on children's eyelashes.
- If you react: stop and report it. In France, ANSES received 378 cosmetovigilance reports in 2024.
FAQ
Is it okay to put castor oil on eyelashes every night?
It is not the right starting point: begin with 1 to 3 evenings a week for 4 to 8 weeks, then adjust. Tolerance of daily application has only been documented over 4 weeks.
What is the best oil for eyelash growth?
No oil has shown an effect on the length or density of eyelashes. Castor oil coats and adds gloss, and jojoba oil is there to thin it. The useful criterion is the label: a single ingredient, with no prostaglandin analogue.
Castor oil for eyelashes reviews: what do they say, and what do they prove?
Reviews report lashes that feel more supple, look glossier and break less. They prove nothing about length or density: without a controlled photo, a general impression cannot separate the oil from the natural renewal of the lashes.
Can you use castor oil on eyelashes with extensions or contact lenses?
With extensions, no: the adhesive does not tolerate oils and the extensions may come loose. With contact lenses, yes, taken out before you apply the oil and put back in the next morning after rinsing.