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Castor oil is a multipurpose 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 during production deactivates the ricin, 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, people burned castor oil as fuel in lamps, used it as a natural remedy to treat ailments like eye irritation, and even took it to stimulate labor in pregnancy (1).

Today castor oil remains a popular natural treatment for common conditions, such as constipation and skin ailments, and you can often find it in natural beauty products.

Here are 4 potential benefits and uses of castor oil. We also cover its use as a hair treatment and precautions to consider.

Perhaps one of the best-known medicinal uses for castor oil is as a natural laxative.

It’s classified as a stimulative laxative, meaning that it increases the movement of the muscles that push material through the intestines, helping clear the bowels. Castor oil is approved by the Food and Drug Administration (FDA) as a stimulative laxative (2).

Stimulative laxatives act rapidly and are commonly used to relieve temporary constipation or to clean out the bowel before medical procedures.

Here’s generally how it works: When you consume castor oil by mouth, it’s 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).

Several studies have shown that castor oil can relieve constipation.

For example, a 2011 study found that when older adults took castor oil, they experienced decreased symptoms of constipation, including less straining during bowel movements and lower reported feelings of incomplete bowel movements (3).

What’s more, another study demonstrated that castor oil was effective at cleansing people’s bowels before they underwent a noninvasive type of colonoscopy called a colon capsule endoscopy (4).

While castor oil is considered safe in small doses, larger amounts can cause abdominal cramping, nausea, vomiting, and diarrhea (2, 5).

Although it can be used to relieve occasional constipation, castor oil is not recommended as a treatment for long-term health concerns.

Also, make sure to speak with a healthcare professional to get their recommendation before using castor oil to treat constipation. Misusing castor oil can lead to dangerous side effects, like electrolyte and acid-base imbalances, which could be life threatening (2).

Summary

People use castor oil as a natural remedy for occasional constipation. It’s approved by the FDA as a stimulative laxative. However, it can cause side effects, like cramping and diarrhea, and you should not use it to treat chronic constipation.

Castor oil is rich in ricinoleic acid, a monounsaturated fatty acid. These types of fats can be used to moisturize the skin. They act as occlusive moisturizers, which prevent or reduce water loss through the outer layer of the skin. (6, 7).

Castor oil is used in cosmetics to promote hydration. Manufacturers often add it 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 may irritate the skin and harm overall health (8).

Swapping out these products for castor oil can help reduce your exposure to these additives. Plus, castor oil is inexpensive and you can use it on both your face and body.

Castor oil is thick, so people often mix it with other skin-friendly oils — like almond, olive, and coconut oil — to make an ultra-hydrating moisturizer. Though applying castor oil to the skin is considered safe for most, it can cause an allergic reaction in some people (9).

Also, using pure castor oil may irritate some people’s skin, so it’s best to dilute it with another oil, like jojoba or coconut oil. Try testing the combination on a small area of skin to see how your skin tolerates castor oil before applying it on larger areas (10).

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 or irritation in some people.

Applying castor oil to wounds creates a moist environment that may help promote healing and prevent 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 balsamum tree (10).

Venelex is used as a wound dressing for chronic and acute wounds and skin ulcers, including (11):

  • pressure ulcers
  • diabetic ulcers
  • burns
  • surgical wounds

It helps reduce odors, protect wounds, and create a moist environment to promote healing (11).

Additionally, ricinoleic acid, the main fatty acid found in castor oil, has anti-inflammatory and pain-reducing properties. It may help reduce skin inflammation, support healing, and aid in pain reduction in people with wounds (12).

Studies have found that ointments containing castor oil may be effective for treating a number of different wounds.

In a 2013 case study, treatment with a spray containing a combination of balsam of Peru, castor oil, and an enzyme called trypsin helped heal an abdominal surgical wound in an 81-year-old man who was unable to tolerate other forms of topical therapy (13).

Keep in mind that castor oil topical wound treatments contain a combination of ingredients, not just castor oil. You should not apply castor oil to any wound without checking with a healthcare professional first.

Summary

Some people apply castor oil to wounds to promote healing. Often it’s mixed with other medicinal ingredients, like Peru balsam, for this purpose.

A number of bacteria and fungi, including Candida fungi, commonly grow on dentures. This can create oral concerns if dentures aren’t properly cleaned and stored (14).

Candida species, like C. albicans, are especially problematic for people who wear dentures because they easily adhere to denture surfaces and mouth tissues.

An overgrowth of Candida fungi can lead to a condition called denture stomatitis, an infection that leads to inflammation, redness, and irritation in the mouth (15).

Interestingly, cleaning dentures with castor oil may help reduce the risk of developing denture stomatitis because castor oil can help kill bacteria and fungi.

One study found that soaking contaminated acrylic teeth in a solution containing 10% castor oil for 20 minutes helped reduce the number of C. albicans as well as other harmful bacteria, including Streptococcus mutans and Staphylococcus aureus (16).

What’s more, a 2013 study in 30 older people with denture-related stomatitis showed that treatment with a castor oil-containing mouthwash led to improvements in the clinical signs of stomatitis, including inflammation (17, 18).

Additionally, another study found that brushing with and soaking dentures in a solution containing castor oil led to significant reductions in Candida in older people who wore dentures (19).

Summary

Several studies have shown that castor oil may help reduce harmful bacteria and fungi in dentures and may help improve symptoms related to a condition called denture stomatitis, which can cause inflammation in the mouth.

Many people use castor oil as a natural hair treatment. This is because castor oil has moisturizing properties, which could help lubricate the hair shaft, increasing flexibility and decreasing the chance of breakage (20).

Even though some people regularly use castor oil as part of their hair care routine, there’s currently no scientific evidence that castor oil helps promote hair health, stimulates hair growth, or reduces hair loss (21).

The same goes for using castor oil on your eyelashes. Some people use castor oil for eyelash growth, but no scientific research has shown this is actually effective.

Castor oil is also commonly used as a treatment for dandruff, a common scalp condition characterized by dry, flaky skin on the head. While some effective hair treatments for dandruff do contain castor oil as an ingredient, there’s no evidence that castor oil on its own is effective for treating dandruff (22).

In fact, castor oil could lead to a condition called acute hair felting in people with long hair. This condition causes the hair to become twisted and tangled, resembling a hard bird’s nest (23).

One case study reported that after a 20-year-old woman with long hair used a combination of coconut oil and castor oil on her hair, it became severely matted immediately after washing. The study authors suggested that the thickness of the castor oil combined with the women’s very long hair led to sudden felting (23).

Typically, acute hair felting can’t be treated and the hair must be cut off.

Even though this condition is rare, people with long hair should be cautious when using castor oil as a hair treatment.

Summary

Although many people use castor oil to moisturize their hair and scalp, there’s currently no evidence that castor oil has any benefits for hair health.

Many people use castor oil to treat a variety of concerns, 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.

If you’re interested in using castor oil, it’s important to keep the following potential side effects in mind:

  • Labor. Medical professionals sometimes use castor oil to induce labor in pregnant people. For this reason, people at all stages of pregnancy should avoid consuming castor oil (24).
  • Gastrointestinal (GI) side effects. While it can be an effective way to alleviate constipation, castor oil may cause GI side effects, like diarrhea, vomiting, cramping, and bloating. It may also cause dizziness. Only use it for constipation under medical supervision (2).
  • 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 (10).

Additionally, people with certain health conditions — including appendicitis, gastrointestinal obstruction, bowel perforation, and inflammatory bowel disease (IBD) — should avoid stimulative laxatives like castor oil because they could cause serious side effects (2).

In general, you should not consume castor oil to treat any medical condition or symptoms, especially in high doses, unless advised by a physician. Misuse of any laxative, including castor oil, can be dangerous and lead to life threatening electrolyte and acid-base imbalances.

If you’re interested in using castor oil to treat any health condition, including constipation, be sure to get advice from a trusted healthcare professional first (2).

Summary

Castor oil can cause side effects, such as allergic reactions and diarrhea, in some people. It can also induce labor, so pregnant people should avoid it.

People have used castor oil for thousands of years as a natural treatment for a variety of health issues.

It can help relieve constipation and may even be used as a natural skin moisturizer and denture treatment.

Though many people use castor oil as a treatment for dry or thinning hair, there’s no evidence that castor oil is effective for improving hair health or stimulating hair growth when used on its own.

If you’re interested in using castor oil for constipation or any other health condition, talk with your healthcare professional first to determine whether castor oil is safe and appropriate to use for your specific health needs.

Just one thing

Try this today: If you experience frequent constipation, there are a few treatments that may help.

Making dietary and lifestyle changes, such as increasing fluid intake, eating more fiber-rich foods, and being more active, can often help improve constipation.

However, it’s important to visit a healthcare professional if you’re experiencing frequent or chronic constipation that doesn’t seem to improve. It can be a sign of an underlying medical condition and can become dangerous if it goes untreated.