Overview

Castor is a plant that produces seeds (beans). Castor oil is produced from ripe seeds that have had their outer covering (hull) removed. Castor oil has been used as a medicine for centuries.

Castor oil is used for constipation and bowel preparation prior to colonoscopy, childbirth, and many other conditions, but there is no good scientific evidence to support these uses.

The hull of the castor seed contains a deadly poison called ricin. This is why the hull must be removed before use. Ricin has been tested as a chemical warfare agent. Weapons-grade ricin is purified and produced in particles that are so small they can be breathed in.

How does it work ?

Castor bean is used to make castor oil, which is a strong laxative. In pregnancy, castor oil might start labor by stimulating the uterus.

Uses & Effectiveness ?

Possibly Effective for

  • Emptying the colon before a colonoscopy. Taking a single dose of castor oil might be effective for emptying the colon. However, it does not seem to work as well as other bowel preparations, such as sodium phosphate or bisacodyl plus magnesium citrate. Castor oil is not recommended for people who are preparing for a colonoscopy.
  • Constipation. Castor oil works as a stimulant laxative for reducing constipation when taken by mouth.
  • Dry eye. Using eye drops containing castor oil might reduce symptoms in people with dry eyes.
  • Childbirth. Taking a single 60 mL dose of castor oil might start labor within 24 hours in some women who are at their delivery date but have not gone into labor.

Insufficient Evidence for

  • Birth control. Early research suggests that taking a single dose of castor seeds with the outer coat removed might prevent pregnancy for up to 8-12 months.
  • Swelling and sores in the mouth. Early research shows that using a specific castor oil mouthwash (Perioquil) 4 times daily for up to 30 days can improve mouth sores in elderly people who have dentures.
  • Syphilis.
  • Arthritis.
  • Skin disorders.
  • Boils.
  • Blisters.
  • Swelling (inflammation) of the middle ear.
  • Migraines.
  • Softening cysts.
  • Adhesive bowel obstruction.
  • Warts.
  • Bunions and corns.
  • Promoting the flow of breast milk.
  • Other conditions.
More evidence is needed to rate the effectiveness of castor for these uses.

Side Effects

When taken by mouth: Castor oil is LIKELY SAFE for most people when taken as a single dose. In some people, castor oil can cause stomach discomfort, cramping, nausea, and faintness. When taken long-term or in large doses, castor oil is POSSIBLY UNSAFE. It might cause fluid and potassium loss from the body when used for more than a week or in doses of more than 15-60 mL per day.

Castor seeds that have had the outer coat removed (hulled) are POSSIBLY SAFE when taken as a single dose.

Consuming the whole castor seed is UNSAFE. The outer coating (hull) of the castor seed contains a deadly poison called ricin. This outer coating can cause nausea, vomiting, diarrhea, abdominal pain, dehydration, shock, severe fluid and chemical disturbances, damage to the liver, kidney, and pancreas, and death. Chewing as few as 1-6 whole seeds can kill an adult.

When applied into the eye: Castor oil eye drops are POSSIBLY SAFE when used for up to 30 days.

Special Precautions and Warnings

When taken by mouth: Castor oil is LIKELY SAFE for most people when taken as a single dose. In some people, castor oil can cause stomach discomfort, cramping, nausea, and faintness. When taken long-term or in large doses, castor oil is POSSIBLY UNSAFE. It might cause fluid and potassium loss from the body when used for more than a week or in doses of more than 15-60 mL per day.

Castor seeds that have had the outer coat removed (hulled) are POSSIBLY SAFE when taken as a single dose.

Consuming the whole castor seed is UNSAFE. The outer coating (hull) of the castor seed contains a deadly poison called ricin. This outer coating can cause nausea, vomiting, diarrhea, abdominal pain, dehydration, shock, severe fluid and chemical disturbances, damage to the liver, kidney, and pancreas, and death. Chewing as few as 1-6 whole seeds can kill an adult.

When applied into the eye: Castor oil eye drops are POSSIBLY SAFE when used for up to 30 days. Pregnancy and breast-feeding: Using castor oil in pregnant women at term (ready to deliver) is POSSIBLY SAFE. Midwives routinely use castor oil for starting labor in pregnant women who are ready to deliver. However, castor oil should not be used for this purpose without the supervision of a healthcare provider. Also, it is LIKELY UNSAFE to use castor oil in pregnant women who are not at term. It might bring on labor too early. It is UNSAFE for women who are pregnant to take whole castor seeds by mouth, as it can cause serious toxic effects or death.

There isn't enough reliable information to know if castor oil is safe to use when breast-feeding. Stay on the safe side and avoid use.

Children: Castor oil is POSSIBLY SAFE when taken by mouth in appropriate doses short-term (less than one week). Castor oil is POSSIBLY UNSAFE when taken by mouth for more than one week or at a high dose. Taking more than the typical children;s dose of 1-15 mL per day, depending on age, can cause a chemical imbalance in the body. Castor seeds are UNSAFE if the whole seed is taken by mouth.

Intestinal problems: Don't use castor oil if you have a blocked intestine, unexplained stomach pain, or problems with your bile ducts or gall bladder.

Interactions ?

    Moderate Interaction

    Be cautious with this combination

  • Water pills (Diuretic drugs) interacts with CASTOR BEAN

    Castor oil is a laxative. Some laxatives can decrease potassium in the body. "Water pills" can also decrease potassium in the body. Taking castor oil along with "water pills" might decrease potassium in the body too much.

    Some "water pills" that can decrease potassium include chlorothiazide (Diuril), chlorthalidone (Thalitone), furosemide (Lasix), hydrochlorothiazide (HCTZ, HydroDIURIL, Microzide), and others.

Dosing

The following doses have been studied in scientific research:

ADULTS

BY MOUTH:
  • For constipation: 15 mL of castor oil is commonly used.
  • For emptying the colon before a colonoscopy: 15-60 mL of castor oil given 16 hours before the procedure.
  • For childbirth: A variety of dosage schedules have been used. Single doses vary from 5-120 mL of castor oil. A one-time dose of 60 mL in fruit juice is commonly used.
CHILDREN

BY MOUTH:
  • For emptying the colon before a colonoscopy: For children younger than 2 years, 1-5 mL is commonly used. For children 2-11 years of age, 5-15 mL is typically used. The dose for children over 12 is 15-60 mL given 16 hours before the procedure.
View References

CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

This copyrighted material is provided by Natural Medicines Comprehensive Database Consumer Version. Information from this source is evidence-based and objective, and without commercial influence. For professional medical information on natural medicines, see Natural Medicines Comprehensive Database Professional Version.
© Therapeutic Research Faculty 2020.