Castor oil for acne: what a 2026 review found

No study has tested castor oil itself on acne. A 2026 review of castor oil in skin medicine found one acne study, and in that study a chemically changed form of the oil was a helper ingredient in a gel whose drug was adapalene. This page is part of Skinli's guide to home remedies for acne.

Skinli gives general education and is not a doctor. For this page, Skinli read one full review, the published summaries (abstracts) of two safety reports, a product label and two case report titles. No source read for this guide gives a way to use castor oil on acne, so this page gives none.

Castor oil is sold in the US as a laxative

MedlinePlus, the health site of the US National Library of Medicine, describes it this way: "Castor oil is a yellowish liquid often used as a lubricant and in laxatives." It adds: "Castor oil comes from the seeds of the castor oil plant."

Skinli read a store-brand castor oil label on DailyMed, the library's label database. Its active ingredient is "Castor oil USP 100%", its purpose is "Stimulant laxative", and its one use is "for relief of occasional constipation". The oil is swallowed for that use. The label says nothing about skin. On October 11, 2026, DailyMed listed 226 castor oil labels, and the first 14 shown were laxative liquids, apart from one prescription ointment.

Two safety facts come from the same sources. Castor seeds contain a poison called ricin, and a 2007 safety report says: "Castor oil does not contain ricin because ricin does not partition into the oil." MedlinePlus says of swallowing: "Large amounts of castor oil can be poisonous."

The one acne study used a changed form of the oil

The review appeared in the journal Cureus in February 2026. Its authors searched the medical literature up to April 20, 2025, and declare no outside funding. Its acne section has one study.

That study tried to carry more adapalene into the skin. Adapalene is a retinoid, a medicine related to vitamin A, and it is one of the acne ingredients the American Academy of Dermatology (AAD) names. The review describes the test gel: "A component of this formulation was hydrogenated castor oil, along with isopropyl myristate, ethanol, and water in a fixed ratio to adapalene". Hydrogenated castor oil is castor oil whose chemical structure has been changed. The review says such changed forms often work as helper ingredients in a product. It also says: "The abstract did not report the concentration of hydrogenated castor oil".

The one study the review found is therefore a study of an adapalene gel, and plain castor oil on a pimple remains untested. The review's summary ends with a call for more research, "warranting further clinical investigation to fully establish its efficacy and optimal use."

What castor oil does in cosmetics

Castor oil is a common cosmetic ingredient. A 2007 report by the Cosmetic Ingredient Review, a panel that the FDA describes as the cosmetics industry's own body for reviewing ingredient safety, gives the figures:

• "Castor oil and Hydrogenated Castor Oil reportedly were used in 769 and 202 cosmetic products, respectively, in 2002"
• "The highest reported use concentration (81%) for castor oil is associated with lipstick."

The report says castor oil and its main fatty acid, ricinoleic acid, act mainly as skin-conditioning agents in cosmetics. The panel looked again in 2025 and concluded that these ingredients "are safe as cosmetic ingredients in the practices of use and concentrations as described in the safety assessment." That finding is limited to safety inside finished products.

The 2007 report gives one more fact that matters for a face with acne medicine on it: "Castor oil and Ricinoleic Acid can enhance the transdermal penetration of other chemicals." Transdermal means through the skin. No source read for this guide says what that does when castor oil goes on over an acne treatment.

The AAD names castor oil on one page read for this guide, and the page is about lips. "Castor seed oil" is the first item in its list of ingredients that can help heal chapped lips.

Pores and allergy: what is known

Pores. No source read for this guide gives a pore-clogging rating for castor oil, and no study tested it on people with acne. The general advice covers every oil. NICE, which writes the acne guideline for England, tells people with acne to "avoid oil-based and comedogenic preparations". Comedogenic means able to clog pores. The AAD says: "Use oil-free skin care products and cosmetics." The NHS page on emollients, which are moisturizing treatments, lists "blocked or inflamed hair follicles (folliculitis) that may cause boils" among their possible reactions. Skinli's guide to what non-comedogenic means explains the label.

Irritation. The 2007 report says undiluted castor oil irritated rabbit skin badly in one study and mildly in another. Those are animal tests.

Allergy. The 2026 review says "patients encounter contact dermatitis to castor oil in cosmetic and hygiene products such as makeup, shampoo, and deodorant", and adds: "This is rare but may still occur." Contact dermatitis is a rash from something that touched the skin. The review describes three cases:

• A deodorant. A person had a rash in the armpit. In a patch test, where a small amount of a substance is placed on the skin, "the patient reacted to undiluted castor oil but not when diluted with petrolatum". Ten other people tested with the same oil had no reaction.
• Lipsticks. A woman had itching, darkening and swelling of the lips for over a year. She "had a positive skin reaction on the patch test to the 30% ricinoleic acid (the main ingredient of castor oil) as well as to many commercial lipsticks".
• An ear wax product. A person's face swelled within hours of using it, and the patch test was positive for castor oil alone. The case report has the title "Angioedema-like allergic contact dermatitis to castor oil." Angioedema is swelling under the skin.

The AAD says of products sold as natural: "Even "natural" or "clean" skin care products can cause a skin reaction." The page on coconut oil for acne covers the oil that has been studied most.

What the AAD, the NHS and the FDA rule support, and when to see a doctor

• The AAD: "Choose a product that contains one of these acne-fighting active ingredients: adapalene, azelaic acid, benzoyl peroxide, or salicylic acid."
• The NHS: "try acne treatments you put on your skin such as salicylic acid or benzoyl peroxide".
• The FDA rule for acne drugs sold without a prescription: benzoyl peroxide, salicylic acid, sulfur, and sulfur combined with resorcinol. No plant oil is on the list.

The AAD's acne pages name a maker of prescription acne drugs as their supporter. Skinli's guide on how to get rid of acne sets these treatments out step by step.

If skin turns red, itchy or swollen after castor oil, the AAD's advice for any product is to "gently wash the product off as soon as possible, and don't use it again." See a doctor for swelling of the face or lips.

For the acne itself, the NHS says to see a GP, which is a family doctor, if "you have lots of spots, or the spots are deep, painful or causing scars". The AAD says: "If you have large, painful pimples that sit deep in your skin or acne that leaves a scar when it clears, you'll need to see a dermatologist for treatment."