Castor oil: what it is and how to use it on skin and hair
Short answer: Castor oil, also called ricinus oil, is a thick, pale yellow oil pressed from the seeds of the castor oil plant (Ricinus communis). It consists of 85 to 92 percent ricinoleic acid and is used in cosmetics to care for skin and hair. You only need a few drops: 2 to 3 for your face, 3 to 5 for your hair or scalp. External use only, and never in your eyes.
Last updated: 5 November 2026 · Written by Florian Fermin
We sell castor oil ourselves. Online you will find the wildest promises about this oil, from longer lashes to fuller hair. We don't make them. Here you can read what castor oil is, what it contains, how to use it according to our label and what research does and doesn't show.
What is castor oil?
Castor oil is a plant oil pressed from the seeds of the castor oil plant, Ricinus communis. The seeds contain 30 to 50 percent oil. India is by far the largest producer and accounts for more than 90 percent of global exports (Patel et al., 2016). Our castor oil comes from India too.
On cosmetic labels, castor oil is listed as Ricinus Communis Seed Oil. That is its INCI name, the international name for cosmetic ingredients. In our bottle it is the only ingredient. According to the label, the oil is organic and cold-pressed.
Castor oil is a cosmetic product. That means the European cosmetics rules apply (Regulation (EC) No 1223/2009): it is meant for external use, and without medical promises. Looking for an oil for your coffee or food? Then you need MCT oil. You will find both among our oils.
Is castor oil the same as ricinus oil?
Yes. Castor oil and ricinus oil are names for exactly the same oil from the seeds of Ricinus communis. In Dutch it is called castorolie, ricinusolie or wonderolie, in German Rizinusöl and in French huile de ricin.
| Name | Where does the name come from? |
|---|---|
| Castor oil | The common English name, from the castor oil plant |
| Ricinus oil | From the Latin plant name Ricinus communis |
| Wonderolie | The Dutch name, after the Dutch name of the plant: wonderboom |
| Ricinus Communis Seed Oil | INCI name on cosmetic labels |
What is in castor oil?
Castor oil consists almost entirely of one fatty acid: ricinoleic acid. Our supplier's specification puts it at 85 to 92 percent. That matches the literature, which mentions up to 90 percent (Patel et al., 2016).
| Fatty acid | Share in our castor oil |
|---|---|
| Ricinoleic acid (C18:1, with OH group) | 85 to 92% |
| Linoleic acid (C18:2) | 2.5 to 7% |
| Oleic acid (C18:1) | 2.5 to 6% |
| Stearic acid (C18:0) | less than 2.5% |
| Palmitic acid (C16:0) | less than 2.5% |
| Linolenic acid and eicosenoic acid | each less than 1% |
Source: our supplier's specification (2026), fatty acid profile as a range.
Ricinoleic acid is special because it has an extra OH group (hydroxyl group) in the molecule. That makes castor oil much thicker than other plant oils, even more viscous than a standard engine oil (SAE 40). The same OH group makes the oil relatively stable: it goes rancid less quickly than many other oils (Patel et al., 2016). In practice this means a small amount goes a long way.
Is castor oil toxic?
No, not the oil itself. The seeds of the castor oil plant contain ricin, a highly toxic protein. Ricin does not dissolve into the oil, so it does not end up in it (Cosmetic Ingredient Review, 2007).
That American expert panel on the safety of cosmetic ingredients assessed castor oil as safe in cosmetics in 2007, and confirmed this in a re-review in 2025 (Fiume et al., 2025). Two things still matter: never eat the seeds of the castor oil plant, and don't swallow our castor oil. It is a cosmetic oil, for external use only.
What do you use castor oil for?
Castor oil is a cosmetic oil for caring for skin and hair. In cosmetics it works mainly as a skin conditioning ingredient and as a helper that keeps a product stable. You will find it in lipstick, for example, sometimes at up to 81 percent (Cosmetic Ingredient Review, 2007).
What do you use it for yourself? Our label lists three uses: face and skin, hair and scalp, and eyebrows and lashes. How to do that is explained below. Worried about your skin, scalp or hair? Then see your GP. A cosmetic oil is not meant for that.
How do you use castor oil?
Use a few drops: 2 to 3 on cleansed skin or 3 to 5 in your hair or on your scalp. These are the amounts on our label:
| Where | How much | How |
|---|---|---|
| Face and skin | 2 to 3 drops | Apply directly to cleansed skin |
| Hair and scalp | 3 to 5 drops | Massage into the hair or scalp |
| Eyebrows and lashes | 1 to 2 drops | Apply in the evening with a clean brush |
Using castor oil for the first time? Here is how to go about it:
- Do a patch test first (see below).
- Start with the lowest amount on the label.
- Rub the drops briefly between your fingertips. That makes the thick oil easier to spread.
- Apply the oil to clean skin or clean hair.
- Does it sting or itch, or does your skin turn red? Stop and rinse the oil off.
Find castor oil too thick or too sticky? Many people mix it with a lighter oil, such as jojoba oil or argan oil. There is no fixed ratio. Start with a little castor oil and add more if you like the texture.
Castor oil on your face: what to keep in mind
Apply 2 to 3 drops to cleansed skin. You don't need more: castor oil is thick and stays on your skin for a long time. Do a patch test first, especially if you have sensitive skin.
Does castor oil clog your pores? That has not been studied well. The well-known lists of comedogenic ingredients originally come from animal tests. Dermatologists who tested finished products on human skin found that a product containing such an ingredient does not automatically clog pores (Draelos and DiNardo, 2006). So you only find out how your skin reacts by trying it. That is why you start small.
Castor oil in your hair: how to do it
Massage 3 to 5 drops into your hair or scalp. More is not better here either: castor oil is so viscous that too much makes your hair heavy and greasy, and it is hard to wash out. You often need to shampoo twice. A detailed guide for hair and scalp is in castor oil for hair and scalp: how to use it.
If you have long hair, be extra sparing. Researchers in India described someone with long hair whose entire scalp hair became irreversibly matted, right after coconut oil and castor oil had been used after washing. The hair had to be cut off. According to the authors, the thick castor oil and the long hair played a role together (Maduri et al., 2017). That is one described case and it is rare, but it is a good reason to work with just a few drops.
Does castor oil make your hair or lashes grow?
There is no good evidence for that, and we don't promise it either. A systematic review of 22 studies on coconut, castor and argan oil for hair found no strong evidence that castor oil makes hair grow. The researchers did find weak evidence for more shine (Phong et al., 2022).
| Question | What has been studied? | Conclusion |
|---|---|---|
| Growth of scalp hair | Systematic review of 22 studies (2022) | No strong evidence |
| Hair shine | The same review | Weak evidence |
| Growth of lashes or eyebrows | No controlled study in humans found (our PubMed search, November 2026) | No evidence |
Our label does say you can apply the oil to eyebrows and lashes, as care. Do this with a clean brush, only on the hairs and not on the rim of your eyelid.
Is castor oil safe? Side effects and precautions
For most people, yes, when used externally. In studies in humans, castor oil caused no significant irritation or allergy, and allergic reactions are rare in practice (Cosmetic Ingredient Review, 2007). Rare is not never: dermatologists in Madrid described a teenager with an allergic reaction on the lips caused by castor oil in a lip balm (Sánchez-Herrero et al., 2018).
How to do a patch test:
- Apply 1 drop to the inside of your forearm.
- Leave it for a day and check whether your skin turns red, itches or stings.
- Does your skin react? Then don't use the oil.
Also keep these points in mind:
- Not in your eyes. Our label says: avoid contact with eyes. In studies where castor oil was dropped into the eyes, researchers saw discomfort and minor damage to the surface of the cornea (Cosmetic Ingredient Review, 2007). Eye doctors also warn against the TikTok trend of rubbing castor oil into your eyes (Al Hassan et al., 2024). If you get oil in your eye, rinse with water.
- External use only. Do not swallow it, not even in small amounts.
- Irritated or broken skin: don't use the oil there.
- Children: keep the bottle out of their reach, as stated on the label.
- Pregnant or breastfeeding: use the oil externally only and, if in doubt, talk to your midwife or GP.
How do you store castor oil and how long does it keep?
Store castor oil in a cool, dry place away from direct sunlight and close the bottle tightly after use. Once opened, our castor oil keeps for 24 months. You can tell from the symbol of an open jar with "24 M" on the label. That symbol comes from the European cosmetics regulation (Article 19 of Regulation 1223/2009).
Does the oil suddenly smell rancid or different from what you are used to? Then stop using it.
What to look for when buying castor oil
Look at the ingredient, the pressing method and the packaging. These are the differences you will come across:
| Type | How is it made? | What do you notice? |
|---|---|---|
| Cold-pressed | Pressed mechanically without high temperatures | Lighter in colour and a lower acid value than oil extracted with a solvent |
| Solvent-extracted | Remaining oil taken from the press cake with a solvent such as hexane | Often refined afterwards |
| Refined | Purified, bleached and sometimes deodorised | Almost colourless, little odour |
Source for cold-pressed, solvent extraction and refining: Patel et al., 2016.
What we look for ourselves:
- One ingredient: only Ricinus Communis Seed Oil on the label, with no added fragrance or colourings.
- Cold-pressed and organic: if the label says so, you know how the oil was made.
- Dark glass bottle: protects the oil from light.
- Period after opening: the open jar symbol with the number of months.
Our castor oil comes in a 500 ml glass bottle and ticks these boxes. Buy castor oil from GOYU, or compare all our skin oils side by side. In our skin and hair collection we explain the difference between a skin oil and a supplement.
Summary in 3 points
- Castor oil and ricinus oil are the same thick oil from the seeds of the castor oil plant, with 85 to 92 percent ricinoleic acid. The oil itself contains no ricin.
- Use a few drops as stated on the label: 2 to 3 for your face, 3 to 5 for your hair. External use only, not in your eyes, and do a patch test first.
- There is no good evidence that castor oil makes hair, lashes or eyebrows grow. So we don't promise that either.
Frequently asked questions
Can you use castor oil every day?
Our label gives amounts per use, not a maximum number of uses per day. If you use the oil daily, stick to a few drops. Stop if your skin or scalp becomes irritated.
Can you take castor oil internally?
No, not our castor oil. It is a cosmetic product and the label says: for external use only. Keep the bottle out of the reach of children.
What is the difference between castor oil and jojoba or argan oil?
Castor oil is much thicker and consists almost entirely of ricinoleic acid. Jojoba oil is chemically a liquid wax and argan oil consists mainly of oleic acid and linoleic acid. Read the comparison in castor, jojoba or argan oil: which one should you choose?
How long does castor oil keep?
Once opened, our castor oil keeps for 24 months, as the symbol on the label shows. Store it in a cool, dry place away from direct sunlight and close the bottle tightly.
Can you use castor oil when you are pregnant?
Our label has no separate warning about pregnancy. Use the oil externally only, as stated on the label, and never swallow it. If in doubt, talk to your midwife or GP.
Sources
- Patel VR, Dumancas GG, Kasi Viswanath LC, Maples R, Subong BJJ. Castor oil: properties, uses, and optimization of processing parameters in commercial production (review). Lipid Insights. 2016;9:1-12. doi:10.4137/LPI.S40233. PubMed 27656091
- Cosmetic Ingredient Review Expert Panel. Final report on the safety assessment of Ricinus Communis (Castor) Seed Oil and ricinoleates in cosmetics (animal and human studies). Int J Toxicol. 2007;26 Suppl 3:31-77. doi:10.1080/10915810701663150. PubMed 18080873
- Fiume MM, Bergfeld WF, Belsito DV, et al. Re-review summary of Ricinus Communis (Castor) Seed Oil and ricinoleates as used in cosmetics. Int J Toxicol. 2025;44(3_suppl):117S-122S. doi:10.1177/10915818251361102. PubMed 40932363
- Phong C, Lee V, Yale K, Sung C, Mesinkovska N. Coconut, castor, and argan oil for hair in skin of color patients: a systematic review of 22 studies. J Drugs Dermatol. 2022;21(7):751-757. doi:10.36849/JDD.6972. PubMed 35816075
- Maduri VR, Vedachalam A, Kiruthika S. "Castor oil": the culprit of acute hair felting (case report). Int J Trichology. 2017;9(3):116-118. doi:10.4103/ijt.ijt_22_17. PubMed 28932063
- Sánchez-Herrero A, Mateos-Mayo A, Rodríguez-Lomba E, et al. Allergic contact cheilitis in an adolescent to castor oil in a lip balm (case report). Contact Dermatitis. 2018;79(3):176-178. doi:10.1111/cod.13016. PubMed 29749619
- Draelos ZD, DiNardo JC. A re-evaluation of the comedogenicity concept (study in 6 people testing finished products on the skin). J Am Acad Dermatol. 2006;54(3):507-512. doi:10.1016/j.jaad.2005.11.1058. PubMed 16488305
- Al Hassan S, Bou Ghannam A, Saade JS. Narrative review of TikTok trends affecting the eye health of children and adolescents, including castor oil in the eyes. Ophthalmol Ther. 2024;13(4):895-902. doi:10.1007/s40123-024-00885-3. PubMed 38315349
- Regulation (EC) No 1223/2009 of the European Parliament and of the Council on cosmetic products. EUR-Lex
- GOYU, label and product page Castor Oil (ingredient, directions for use, warnings, period after opening) and supplier specification (fatty acid profile), consulted 5 November 2026.
Want to try our organic, cold-pressed castor oil? Buy castor oil from GOYU. Want to look at your diet as well? Read nutrition and your skin.
This article is for information only and is not medical advice. Castor oil is a cosmetic product for external use. If you are worried about your skin, scalp or hair, are pregnant or in doubt, talk to your GP.
Castor oil from GOYU
Organic, cold-pressed castor oil in a 500 ml glass bottle. One ingredient: Ricinus Communis Seed Oil. For face, body and hair.
