Castor Bean: Source of Castor Oil and Deadly Ricin

The source of one of the world’s most poisonous toxins, the castor bean (Ricinus communis) has deadly, but also interesting medical potential. It can be a popular garden plant because of its attractive foliage and seed heads, but it is also grown commercially to create castor oil. Castor bean belongs to the Spurge family of plants, which also includes the most poisonous tree in the World, manchineel.

It also belongs to its own unique genus (Ricinus) and is the subject of numerous scientific studies – each either analyzing its potential health benefits, or the effects of its toxin…

What Are The Active Compounds in Castor Bean?

Castor bean contains a mix of beneficial, but also incredibly deadly toxins. The pulp of the seeds (known as beans) contain ricin, which is a deadly toxin — however, the roots, bark, and seed oil (created by separating oil from seed pulp) hold medicinal properties.

Castor bean as a whole is highly allergenic, which means allergic reactions to the plant are fairly common and quite severe. If you suffer from asthma the plant is best avoided as it can be a trigger for a bad asthmatic reaction.

Castor bean seeds | Photo from Wikimedia Commons

What Are The Symptoms of Castor Bean Poisoning?

Ricin is a toxin that can poison humans through inhalation, injection, or ingestion. It can even enter the body if it gets in contact with the eyes or an open wound. When inside the body, ricin inhibits protein synthesis in cells, which is a process essential for life.

Symptom onset will vary between adults and children, and also how the toxin entered the body. Because ricin stops protein synthesis, symptoms will generally not show until several hours after it has entered the body. Symptoms include vomiting, severe abdominal pain, diarrhea, severe loss of fluids, serious organ damage, and in most cases death. Chewing a single seed has the potential to cause death.

What is the Medicinal Potential of Castor Bean?

Studies have shown that castor bean roots and oil (extracted from seeds but separated from seed pulp) have a number of small health benefits. Castor oil can be bought in health shops and used as a laxative. It’s used within traditional Ayurveda treatments to treat constipation, arthritis and was also once used to induce labor.

It may also hold anti-inflammatory properties and has also shown that it may give some minor protection to the liver from other poisons, but studies are limited.

Ripening castor bean seed pods | Photo by Onjacktallcuca on Wikimedia Commons

Cultural Symbolism & Uses of Castor Bean

The castor bean plant has had an extremely varied usage throughout history. We’ve outlined some notable uses and references below…

  • Castor oil was once used within Egyptian and Greek cultures as a fuel for lamps as it burned slowly.
  • The oil has was also previously used as a nourishing treatment to hydrate the hair and skin. It is still used today is some cosmetics recipes.
  • During the early 1900s the oil was used as a lubricant in engines, and is still grown and manufactured for this purpose today.
  • A teaspoon of castor oil was once a popular herbal treatment for relief of constipation in children and also adults. Bottles of the oil are still available in health shops and pharmacies today.
  • The popular TV series Breaking Bad featured the use of ricin within a plot line. This cultural exposure unfortunately inspired a number of individuals to purchase either castor bean seeds or pure ricin from the dark web. As the sale of castor bean seeds is monitored most were caught and arrested.

Notable Castor Bean Poisonings & Attempts

Ricin was first identified in the late 1800s and has since been used and abused by individuals, organizations, and even countries looking to inflict harm to pursue an agenda. The toxin has been identified as an assassination weapon used by the KGB and other organizations to kill individuals who spoke out against them.

What Does Castor Bean Look Like?

The castor bean is a shrub with very ornamental star-shaped leaves. After flowering in spring, the whole plant is adorned in bright red spikes of seed heads. It’s popular in gardens because of its tropical appearance.

Ricinus communis (castor oil plant) | Photo by Adityamadhav83 on Wikimedia Commons

Where Does Castor Bean Grow?

Castor bean is endemic to Europe, Africa, and Asia — particularly the Mediterranean, East Africa, and also India. As it is cultivated in gardens and also grown commercially, castor bean plants have spread into the wild and can occasionally be found in areas of moist woodland near streams or rivers.

Did You Know…

Castor bean seeds are so potent, it’s considered relatively easy to create poison from them. Because of this, a number of countries and states have made the plant illegal to own, while in other areas around the world it’s simply illegal to extract the ricin.

Ricinus communis (castor oil plant) | Photo by Buendia22 on Wikimedia Commons


Castor bean is a deadly but fascinating plant, with a mixed history of usage, for both good and insidious purposes. The purchase of castor bean seeds is likely monitored by a number of governments due to their incredibly deadly potential, but it is possible to plant them in gardens.

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