Many people dislike the taste of castor oil and may consider it more of a foe than a friend. However, castor oil has a few health benefits. In particular, it can help relieve constipation.

Castor oil isn’t used as often as it once was. Still, it can be helpful as an occasional treatment for constipation, provided you’re able to tolerate the taste and the side effects.

What Is Constipation?

When you’re constipated, you don’t have bowel movements as often as you should, or your stool is hard to pass. The standard definition of constipation is having fewer than three bowel movements per week.

Everyone goes to the bathroom on a different schedule, though. Some people have several bowel movements per day, and other people have just one bowel movement per day or go every other day. Any decrease in bowel movements that’s out of the norm for you may be a sign of constipation.

Hard stools can force you to strain while trying to go to the bathroom. Chronic constipation also causes symptoms like abdominal pain and bloating.

How Is Castor Oil Used to Treat Constipation?

Castor oil comes from the castor bean. People have used this oil as a laxative for thousands of years, but only recently have scientists figured out how it works.

Researchers have discovered that ricinoleic acid, the main fatty acid in castor oil, binds to receptors on the smooth muscle cells of your intestinal walls. Once ricinoleic acid binds to these receptors it causes those muscles to contract and push out stool, just as other stimulant laxatives do. Castor oil has a similar effect on the uterus, which is why it has been used to induce labor.

Castor oil does seem to be effective at relieving constipation, and it works quickly. A 2011 study of older adults with chronic constipation found that castor oil use reduced straining and improved constipation symptoms.

What Causes Constipation?

The cause of constipation is often a fiber- and fluid-poor diet. If you don’t get enough fiber and water, your stool becomes hard and dry. If this happens, your stool can’t move easily through your intestines.

Some medicines can also cause constipation as a side effect. These medications include:

  • antacids
  • antiseizure drugs
  • drugs that lower blood pressure
  • iron supplements
  • narcotic pain relievers
  • sedatives
  • some antidepressants

Certain medical conditions can also lead to constipation, such as:

  • narrowing of the colon
  • colon cancer
  • other tumors of the intestines
  • conditions that affect the muscles in the intestines, such as multiple sclerosis, Parkinson’s disease, and stroke
  • diabetes
  • an underactive thyroid gland, or hypothyroidism

Some people find that they occasionally get constipated, such as when they travel. Pregnant women may get constipated as a result of hormonal changes. Bowel movements also slow with age, leaving some older adults chronically constipated.

Who Can Use Castor Oil for Constipation?

Because castor oil can cause the uterus to contract, it’s not recommended during pregnancy. It’s also not advised for regular use in children under age 12. If you’d like to give castor oil to your child, ask their pediatrician first. In adults over 60, castor oil may make bowel problems worse if it’s used over a long period. It can also lower the amount of potassium in your body.

You may need to avoid castor oil if you take certain medicines, including:

  • diuretics, which can also lower the amount of potassium in your body
  • antibiotics, including tetracycline
  • bone medicines
  • blood thinners
  • heart medicines

Read more: 5 safe remedies for constipation in pregnancy »

In addition to having what many consider to be an unpleasant taste, castor oil has a few side effects. Like other stimulant laxatives, it can cause cramping and diarrhea. It can also reduce the absorption of nutrients in your intestines.

How to Use Castor Oil

Castor oil is a liquid that you take by mouth. There are other laxatives that work slowly overnight, but castor oil is best taken during the day because it works quickly.

The dose of castor oil used to treat constipation in adults is 15 milliliters. To mask the taste, put the castor oil in the fridge for at least an hour to cool it. Then, mix it into a full glass of fruit juice. You can also buy flavored castor oil preparations.

How Long Will You Have to Use Castor Oil for Constipation?

Castor oil works very quickly. You should see results within two to six hours after taking it. Because castor oil works so fast, it’s not a good idea to take it before bedtime as you would with other laxatives.

Like any stimulant laxative, castor oil shouldn’t be taken in the long term. Over time, it can reduce the muscle tone in your intestines and lead to chronic constipation. If you continue to have constipation, see your doctor for another treatment option.

Read more: 6 Natural constipation remedies »

Tips for Preventing Constipation

Lifestyle Changes

Often, the best way to prevent constipation is with diet and exercise. Get more fiber by adding fruits, vegetables, and whole grains to your meals. Fiber softens your stools and helps them pass more easily through your intestines. Aim to eat 14 grams of fiber for every 1,000 calories you consume. Also, drink more fluids to make your stool softer.

Stay active on most days of the week. Just as exercise works the muscles in your arms and legs, it also strengthens the muscles in your intestines.

Try to go to the bathroom at the same time each day. Don’t rush when you go to the bathroom. You should sit and give yourself time to have a bowel movement.


If you still can’t go, try a laxative. The following are a few options:

  • Fiber supplements such as Metamucil, FiberCon, and Citrucel give your stool more bulk so that it’s easier to push out.
  • Osmotics such as Milk of Magnesia and polyethylene glycol (MiraLax) help keep fluid in the stool to soften it.
  • Stool softeners like Colace and Surfak add fluid to the stool to soften it and prevent straining during bowel movements.
  • Stimulants such as Dulcolax, Senokot, and Purge push out stool by contracting the intestines. These types of laxatives are effective, but they can cause side effects such as diarrhea.