Castor oil for skin, lashes and hair
The viral multi-purpose oil
Castor oil went viral on TikTok in 2024 for everything from belly-button 'detox' to lash growth and under-eye lines, a revival of a grandmother's remedy driven by wellness creators rather than any new data.
Search interest: about 2,100 searches a month in Singapore for “castor oil” (Ahrefs, October 2026).
A trend with a shine to it, literally. It conditions what is already there and changes nothing underneath — pleasant, cheap, and not a treatment.
Reviewed against the Aesthetics International standard. Category: Viral routines.
Does Castor oil for skin, lashes and hair work?
Trend. A trend with a shine to it, literally. It conditions what is already there and changes nothing underneath — pleasant, cheap, and not a treatment. A 2022 systematic review of coconut, castor and argan oils for hair found weak evidence that castor oil improves lustre and no evidence that it increases growth.
- Verdict
- Trend Popular for reasons that are mostly social. Harmless at best; manage expectations.
- Evidence base
- 4 PubMed-indexed studies cited below, including systematic reviews.
- Suits
- Dry cuticles, lips, brows and hair ends; people who enjoy a slow, oily ritual at night.
- Not for
- Acne-prone or seborrhoeic skin, the lash line of anyone wearing contact lenses, and anyone expecting hair growth, lifted lids or fewer lines.
- In Singapore
- A cosmetic ingredient; no registration applies.
- Category
- Viral routines · about 2,100 searches a month in Singapore for “castor oil”
- Reviewed
- 1 October 2026 by Aesthetics International. Revised as evidence and regulation change.
What it is
A thick vegetable oil pressed from Ricinus communis seeds, about 90 per cent ricinoleic acid. In cosmetics it is an emollient and a common ingredient in lipsticks and mascaras; medically it is a stimulant laxative when swallowed.
How it works
Applied to skin, castor oil forms an occlusive film that slows water loss and makes skin and hair shafts look glossier and feel softer. Ricinoleic acid has mild anti-inflammatory activity in laboratory work. Nothing in it reaches the hair follicle to change growth, and nothing applied to the navel enters the abdomen.
What the evidence says
A 2022 systematic review of coconut, castor and argan oils for hair found weak evidence that castor oil improves lustre and no evidence that it increases growth. There are no controlled trials of castor oil for lashes, wrinkles or dark circles; the lash-growth videos are measuring conditioning and darkening of existing hairs. The cosmetic ingredient safety review classifies it as safe as used. The literature that does exist is mostly adverse-event reports: allergic contact dermatitis, including an angioedema-like reaction, and an acute hair-felting case in which thick oil matted hair into an irreversible mass.
What people are saying
Paraphrased from public discussion on TikTok, Instagram, Reddit and in the press. Not testimonials, and not about any one clinic. Reported in: sciencefocus.com, cnbc.com.
What the studies show
- systematic review
Castor oil had weak evidence for improved hair lustre and no strong evidence for hair growth or treating infestation.
Coconut, Castor, and Argan Oil for Hair in Skin of Color Patients: A Systematic Review. — Journal of Drugs in Dermatology, 2022. PMID 35816075.
- review
The cosmetic ingredient safety panel reaffirmed castor oil and ricinoleates as safe in cosmetics at current use levels.
Re-Review Summary of Ricinus Communis (Castor) Seed Oil and Ricinoleates as Used in Cosmetics. — International Journal of Toxicology, 2025. PMID 40932363.
- case series
A case of marked facial swelling from allergic contact dermatitis to castor oil in a cosmetic product.
Angioedema-like allergic contact dermatitis to castor oil. — Contact Dermatitis, 2010. PMID 20536483.
- case series
Thick castor oil application was linked to sudden, irreversible matting of scalp hair requiring it to be cut.
"Castor Oil" - The Culprit of Acute Hair Felting. — International Journal of Trichology, 2017. PMID 28932063.
Studies are selected for relevance and quality, not for agreement with the verdict; PubMed records are linked so the reader can check them.
Who it suits
Suits
Dry cuticles, lips, brows and hair ends; people who enjoy a slow, oily ritual at night.
Not for
Acne-prone or seborrhoeic skin, the lash line of anyone wearing contact lenses, and anyone expecting hair growth, lifted lids or fewer lines.
Alternatives
The two reviewed treatments most often weighed against Castor oil for skin, lashes and hair, on the same standard.
| Castor oil for skin, lashes and hair | Hair transplant | Finasteride and dutasteride for hair loss | |
|---|---|---|---|
| Verdict | Trend | Established | Established |
| What it is | A thick vegetable oil pressed from Ricinus communis seeds, about 90 per cent ricinoleic acid. | Moving your own permanent hair follicles from the back and sides of the scalp to thinning areas. | Finasteride and dutasteride block the 5-alpha-reductase enzyme that converts testosterone to dihydrotestosterone (DHT), the hormone that miniaturises genetically sensitive follicles in male pattern hair loss. |
| Evidence base | 4 PubMed-indexed studies cited below, including systematic reviews. | 2 PubMed-indexed studies cited below, including systematic reviews. | 5 PubMed-indexed studies cited below, including systematic reviews, meta-analyses. |
| Suits | Dry cuticles, lips, brows and hair ends; people who enjoy a slow, oily ritual at night. | Stable pattern hair loss with a good donor area, realistic goals, a settled plan for the hair that will keep thinning, and a surgeon who does the surgery. | Men with early to moderate pattern hair loss who want to keep what they have and regain some density, who accept indefinite treatment and the small risk of sexual side effects; often combined with minoxidil and considered before or alongside transplantation. |
| In one line | A trend with a shine to it, literally. It conditions what is already there and changes nothing underneath — pleasant, cheap, and not a treatment. | The question to ask any clinic is who holds the punch, because the donor area is the one thing you cannot grow back. | The side-effect debate is loud and the trial numbers are small; the right conversation is a frank one with a doctor, not a thread. |
Risks
Allergic contact dermatitis, blocked pores, styes or blurred vision if it gets into the eye, and hair felting with heavy, repeated scalp use.
In Singapore
A cosmetic ingredient; no registration applies. Pharmacy-grade castor oil in Singapore is sold as a laxative and is the same oil.
“A trend with a shine to it, literally. It conditions what is already there and changes nothing underneath — pleasant, cheap, and not a treatment.”
Vetted protocols on the same problem
Questions
Does castor oil grow eyelashes?
Is it safe around the eyes?
Does putting it in my belly button do anything?
Cite this review
Aesthetics International (2026). Castor oil for skin, lashes and hair: does it work? Evidence, risks and verdict. https://aesthetics-international.org/treatments/castor-oil-skin-hair/ (reviewed 1 October 2026).
Editorial, unpaid and independent of any manufacturer. Verdict: Trend. See what works and what doesn't across all 153 reviews. Spotted an error or a newer study? Suggest a correction — changes are logged on the corrections page. Terms are defined in the glossary.
Where this review is used
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