Castor oil is a multi-purpose vegetable oil that people have used for thousands of years.
It’s made by extracting oil from the seeds of the Ricinus communis plant.
These seeds, which are known as castor beans, contain a toxic enzyme called ricin. However, the heating process that castor oil undergoes deactivates it, allowing the oil to be used safely.
Castor oil has a number of medicinal, industrial and pharmaceutical uses.
It's commonly used as an additive in foods, medications and skin care products, as well as an industrial lubricant and biodiesel fuel component.
In ancient Egypt, castor oil was burned as fuel in lamps, used as a natural remedy to treat ailments like eye irritation and even given to pregnant women to stimulate labor (1).
Today, castor oil remains a popular natural treatment for common conditions like constipation and skin ailments and is commonly used in natural beauty products.
Here are 7 benefits and uses of castor oil.
Perhaps one of the best-known medicinal uses for castor oil is as a natural laxative.
It’s classified as a stimulant laxative, meaning that it increases the movement of the muscles that push material through the intestines, helping clear the bowels.
Stimulant laxatives act rapidly and are commonly used to relieve temporary constipation.
When consumed by mouth, castor oil is broken down in the small intestine, releasing ricinoleic acid, the main fatty acid in castor oil. The ricinoleic acid is then absorbed by the intestine, stimulating a strong laxative effect (2).
In fact, several studies have shown that castor oil can relieve constipation.
For example, one study found that when elderly people took castor oil, they experienced decreased symptoms of constipation, including less straining during defecation and lower reported feelings of incomplete bowel movements (3).
While castor oil is considered safe in small doses, larger amounts can cause abdominal cramping, nausea, vomiting and diarrhea (4).
Although it can be used to relieve occasional constipation, castor oil is not recommended as a treatment for long-term issues.
Summary Castor oil can be used as a natural remedy for occasional constipation. However, it can cause side effects like cramping and diarrhea and should not be used to treat chronic constipation.
Castor oil is rich in ricinoleic acid, a monounsaturated fatty acid.
These types of fats act as humectants and can be used to moisturize the skin.
Humectants retain moisture by preventing water loss through the outer layer of the skin (5).
Castor oil is often used in cosmetics to promote hydration and often added to products like lotions, makeup and cleansers.
You can also use this rich oil on its own as a natural alternative to store-bought moisturizers and lotions.
Many popular moisturizing products found in stores contain potentially harmful ingredients like preservatives, perfumes and dyes, which could irritate the skin and harm overall health (5).
Swapping out these products for castor oil can help reduce your exposure to these additives.
Plus, castor oil is inexpensive and can be used on the face and body.
Though applying castor oil to the skin is considered safe for most, it can cause an allergic reaction in some people (6).
Summary Castor oil can help lock moisture in the skin. Though this natural alternative to store-bought products is considered safe for most, it can cause allergic reactions in some.
Applying castor oil to wounds creates a moist environment that promotes healing and prevents sores from drying out.
Venelex, a popular ointment used in clinical settings to treat wounds, contains a mixture of castor oil and Peru balsam, a balm derived from the Myroxylon tree (7).
Castor oil stimulates tissue growth so that a barrier can be formed between the wound and the environment, decreasing the risk of infection.
It also reduces dryness and cornification, the buildup of dead skin cells that can delay wound healing (8).
Studies have found that ointments containing castor oil may be especially helpful in healing pressure ulcers, a type wound that develops from prolonged pressure on the skin.
One study looked at the wound-healing effects of an ointment containing castor oil in 861 nursing home residents with pressure ulcers.
Those whose wounds were treated with castor oil experienced higher healing rates and shorter healing times than those treated with other treatment methods (9).
Summary Castor oil helps heal wounds by stimulating the growth of new tissue, reducing dryness and preventing the buildup of dead skin cells.
Ricinoleic acid, the main fatty acid found in castor oil, has impressive anti-inflammatory properties.
Studies have shown that when castor oil is applied topically, it reduces inflammation and relieves pain.
The pain-reducing and anti-inflammatory qualities of castor oil may be particularly helpful to those with an inflammatory disease such as rheumatoid arthritis or psoriasis.
Animal and test-tube studies have found that ricinoleic acid reduces pain and swelling (10).
One study demonstrated that treatment with a gel containing ricinoleic acid led to a significant reduction in pain and inflammation when applied to the skin, compared to other treatment methods (11).
A test-tube component of the same study showed that ricinoleic acid helped reduce inflammation caused by human rheumatoid arthritis cells more than another treatment.
Aside from castor oil’s potential to reduce inflammation, it may help relieve dry, irritated skin in those with psoriasis, thanks to its moisturizing properties.
Although these results are promising, more human studies are needed to determine the effects of castor oil on inflammatory conditions.
Summary Castor oil is high in ricinoleic acid, a fatty acid that has been shown to help reduce pain and inflammation in test-tube and animal studies.
Acne is a skin condition that can cause blackheads, pus-filled pimples and large, painful bumps on the face and body.
It’s most common in teens and young adults and can negatively impact self-esteem.
Castor oil has several qualities that may help reduce acne symptoms.
Inflammation is thought to be a factor in the development and severity of acne, so applying castor oil to the skin may help reduce inflammation-related symptoms (12).
Acne is also associated with an imbalance of certain types of bacteria normally found on the skin, including Staphylococcus aureus (13).
Castor oil has antimicrobial properties that may help fight bacterial overgrowth when applied to the skin.
One test-tube study found that castor oil extract showed considerable antibacterial power, inhibiting the growth of several bacteria, including Staphylococcus aureus (14).
Castor oil is also a natural moisturizer, so it may help soothe the inflamed and irritated skin typical in those with acne.
Summary Castor oil helps fight inflammation, reduce bacteria and soothe irritated skin, all of which can be helpful for those looking for a natural acne remedy.
Candida albicans is a type of fungus that commonly causes dental issues like plaque overgrowth, gum infections and root canal infections (15).
Castor oil has antifungal properties and may help fight off Candida, keeping the mouth healthy.
One test-tube study found that castor oil eliminated Candida albicans from contaminated human tooth roots (16).
Castor oil may also help treat denture-related stomatitis, a painful condition thought to be caused by Candida overgrowth. This is a common issue in elderly people who wear dentures.
A study in 30 elderly people with denture-related stomatitis showed that treatment with castor oil led to improvements in the clinical signs of stomatitis, including inflammation (17).
Another study found that brushing with and soaking dentures in a solution containing castor oil led to significant reductions in Candida in elderly people who wore dentures (18).
Summary Several studies have shown that castor oil may help fight fungal infections in the mouth caused by Candida albicans.
Many people use castor oil as a natural hair conditioner.
Dry or damaged hair can especially benefit from an intense moisturizer like castor oil.
Applying fats like castor oil to the hair on a regular basis helps lubricate the hair shaft, increasing flexibility and decreasing the chance of breakage (19).
Castor oil may benefit those who experience dandruff, a common scalp condition characterized by dry, flaky skin on the head.
Though there are many different causes of dandruff, it has been linked to seborrhoeic dermatitis, an inflammatory skin condition that causes red, scaly patches on the scalp (20).
Due to castor oil’s ability to reduce inflammation, it may be an effective treatment for dandruff that is caused by seborrhoeic dermatitis.
Plus, applying castor oil to the scalp will help moisturize dry, irritated skin and may help reduce flaking.
Summary The moisturizing and anti-inflammatory properties of castor oil make it an excellent option to keep hair soft and hydrated and help reduce dandruff symptoms.
Many people use castor oil to treat a variety of issues, either by ingesting the oil or applying it to the skin.
Although castor oil is generally considered safe, it can cause adverse reactions and unwanted side effects in some people.
- Can induce labor: It’s used by medical professionals to induce birth. For this reason, women at all stages of pregnancy should avoid consuming castor oil (21).
- Can cause diarrhea: While it can be an effective way to alleviate constipation, you may get diarrhea if you take too much. Diarrhea can cause dehydration and electrolyte imbalances.
- Can cause allergic reactions: It may cause an allergic reaction in some people when applied to the skin. First try applying a small amount to a tiny patch of skin to see how your body reacts (22).
Summary Castor oil can cause side effects, such as allergic reactions and diarrhea, in some people. It can also induce labor, so pregnant women should avoid it.
People have used castor oil for thousands of years as a powerful natural treatment for a variety of health issues.
It has been shown to help relieve constipation and moisturize dry skin, among many other uses.
If you are searching for an affordable, multi-purpose oil to keep in your medicine cabinet, castor oil may be a good choice.