The medicinal power of castor oil

Castor tree produces fruits that serve as the basis for castor oil, also called castor oil or castor oil. This oil is not widely known in the Netherlands, but it is a widely used product in English-speaking countries. Perhaps best known is the fact that it is used as a lubricant and brake oil. The brand castor oil was created as a result of brake oil based on the otherwise inedible beans of the castor tree. Other products based on castor oil are: paint, ink, plastic, soap, nylon, floor wax, bath oil, hair fixative and perfume. In small doses, castor oil has medicinal properties. In folk medicine it is used, among other things, for bowel problems and when a heavily pregnant woman seems to have difficulty giving birth to a child. NB! This article is written from the personal view of the author and may contain information that is not scientifically substantiated and/or in line with the general view.

Botanical drawing of castor plant / Source: Franz Eugen Köhler, Wikimedia Commons (Public domain)


  • Traditional use
  • Naming
  • Active substances
  • Castor oil is a laxative
  • With vermifuges
  • Dose and safety
  • Visit a doctor or herbal therapist

Traditional use

Castor oil is traditionally used for diarrhea caused by food poisoning. It is not absorbed by the intestines and as an oil it stimulates the removal of intestinal contents. Heavily pregnant women are also given it if they have problems giving birth. Castor oil appears in the Bible. In the Old Testament, the book of Jonas, God makes a gourd grow in one night. In ancient Greece, Dioscorides, pioneer of medicine and phytotherapy, saw castor oil as an excellent way to care for the skin.


In Latin, castor oil is called Ricinus communis . Ricinus is the Latin word for tick. The beans have a bump that makes them resemble a tick; that is the explanation for the name. In the Middle Ages the miracle tree was called the Christ tree, probably because people associated miracles and Christ with each other. Another explanation for the name miracle tree is that this tree grows very quickly once the seed has germinated; According to this explanation, the prefix ‘miracle’ refers to its great growth power.

Seeds of the castor plant / Source: H. Zell, Wikimedia Commons (CC BY-SA-3.0)

Active substances

The seed and oil from the castor tree are used for phytotherapeutic purposes. This seed contains the following active substances: fatty oil with triacylglycerols such as tricinolein, the unsaturated and hydroxylated C18 fatty acid rinicoleic acid, oleic acid, linoleic acid, ricin and ricinin.

Castor oil is a drug that can have side effects. Only take it on the prescription of a herbal therapist.

Castor oil is a laxative

The main medicinal property of castor oil or castor oil is that it is a purgative and laxative. It should only be used for short periods of time. Triricinolein is the active substance. This glycoside breaks down in the intestines by lipase or fat-splitting enzymes. Rinicoleic acid and sodium salt are then released. This has a stimulating effect on intestinal peristalsis. Another consequence is increased blood flow in the intestinal mucosa.

With vermifuges

When someone has had a treatment with vermifuges such as pumpkin seeds (cucurbita pepo) or male fern (drypteris filixmas), the worm, an intestinal parasite, is paralyzed. It is then important to expel it from the body as quickly as possible. Castor oil can speed up this last process.

Castor oil is the basis for a bioplastic manufactured by chemical giant DSM.

Dose and safety

  • Take one to two tablespoons of castor oil per day, preferably lukewarm.

Ricin is a lectin and therefore a toxin. It is a very deadly substance; the lethal dose is 0.03 grams. The lethal dose for someone weighing 70 kilos is 12 and a half grams of semen. The whole seed in particular is very poisonous. In principle, the oil does not contain ricin, but no risk should be taken. That is why castor oil is best only taken on prescription by a doctor and is only used for a short period of time. Long-term use can lead to nausea, loss of appetite, digestive problems and diarrhea.

Visit a doctor or herbal therapist

Much of the information about the medicinal plant mentioned in this article comes from the book Groot Handboek Medicinal Plants by Geert Verhelst. That is a handbook in phytotherapy. However, it is not suitable for self-healing. Anyone who suffers from something should consult a doctor or herbal therapist for a good diagnosis and choice of the best remedies, tailored to your personal situation. The knowledge and science mentioned here is of a purely informative nature.