Castor is a plant that produces seeds (beans). Castor oil is produced by pressing ripe seeds that have had their outer covering (hull) removed. The hull contains a deadly poison called ricin. Castor oil has been used as medicine for centuries.
Castor seeds without the hull are used for birth control, constipation, leprosy, and syphilis.
Castor oil is used as a laxative for constipation, to start labor in pregnancy, and to start the flow of breast milk.
Some people apply castor seed paste to the skin as a poultice for inflammatory skin disorders, boils, carbuncles, pockets of infection (abscesses), inflammation of the middle ear, and migraine headaches.
Castor oil is used topically to soften skin, bunions and corns; and to dissolve cysts, growths, and warts. It is also applied to the skin for osteoarthritis. Some women put castor oil inside the vagina for birth control or to cause an abortion. Castor oil is used in the eyes to soothe membranes irritated by dust or other materials.
In manufacturing, castor seeds are used to make paints, varnishes, and lubricating oils.
Ricin from the hull of the castor seed 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. The smaller the particle size, the more poisonous the ricin. You may remember that ricin was found in letters sent to some Congress members and the White House, and in the possession of people linked to terrorist and antigovernment groups.
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...
Bowel preparation before colonoscopy. Some research suggests that taking a single dose of castor oil is effective for bowel preparation in people undergoing a colonoscopy. However, castor oil might not be as effective as other bowel preparations, such as sodium phosphate or bisacodyl plus magnesium citrate.
Constipation. Castor oil works as a stimulant laxative for reducing constipation when taken by mouth.
Birth control. There is some evidence that a single dose of castor seeds with the outer coat removed (hulled) can work as a contraceptive for up to 8-12 months.
Dry eyes. Some research suggests that using eye drops containing castor oil might be effective for people with dry eyes.
Stimulating full-term labor in pregnant women. A single 60 mL dose of castor oil appears to start labor within 24 hours in at least half of women at term pregnancy who try it. There is also some evidence that women at term pregnancy whose “water has broken” are more likely to go into labor and are less likely to need a Cesarean section if they take castor oil.