* Throughout the 20th Century, there has only been a serious adverse effect from castor oil posted in medical records. However, toxicity concerns are reasonable. It comes from the castor bean, which contains a highly toxic compound called ricin. Ricin can be fatal, but it's usually eliminated with the cold press and filtering process used for medicinal castor oil.This is similar to oleander or mistletoe. Both are toxic in their basic raw forms, but the extracts have been used to successfully cure cancer. Medicinal castor oil's filtering with the cold press process eliminates all or almost all of the ricin. Castor oil created by extraction is rather toxic and usually used for industrial purposes.
*Never consume Castor oil during pregnancy : Medicinal castor oil should never be used by pregnant women. There is a risk of induced abortion. For others, even if traces of ricin contamination slip into a bottle of cold pressed castor oil, it would take a very large amount of consumption to create an adverse effect.
* Castor oil's main side effects fall into the categories of skin reactions and gastrointestinal upset, which isn't terribly surprising given the agent's actions on your intestinal wall. Castor oil is broken down by your small intestine into ricinoleic acid, which acts as an irritant to your intestinal lining. This effect is what gives castor oil the ability to reverse constipation—but it's also the reason that some people report digestive discomfort, diarrhea, and other gastrointestinal side effects. If you suffer from cramps, irritable bowel, ulcers, diverticulitis, hemorrhoids, colitis, prolapses, or have recently undergone surgery, you should probably avoid castor oil due to these possible adverse reactions.
*Be sure to use only cold-pressed castor oil that is hexane-free. Avoid refined, adulterated oils which can clog the skin's pores. Cold-pressed castor oil retains its valuable nutrients.
*Avoid contact with eyes. Pure cold pressed Castor seed oil is potent (unlike its diluted imitations) and can be an eye irritant similar to pepper spray.