- Although the NIH considers castor oil essentially safe, consuming an excessive amount (overdosing) can be harmful and require medical attention. When used externally, castor oil rubbed onto skin can serve as a moisturizer and protectant. Castor oil used as a scalp treatment can help repair dry or damaged hair, seal in moisture and promote overall hair health. However, castor oil has not been proven to increase hair growth directly.
- Castor oil tends to be light yellow or colorless. It has very little odor and a mild taste. In addition to its popularity as a versatile home remedy, castor oil is often used as an industrial lubricant and as an ingredient in soap, bath oil, paints, perfumes and plastics. Industrial castor oil is prepared differently than the cold-pressed castor oil designed for home use or consumption.
- Castor oil comes form the castor bean plant (ricinus communis)--a visually striking, fast-growing plant with star-shaped leaves and clusters of white or pink flowers. Seeds found inside the male castor flowers are the source of castor oil. They also contain toxic substances such as ricin, which is considered a biological weapon and has been used in political assassination attempts. Castor beans are thus highly poisonous for adults, children and animals. Although the pressing process that produces castor oil removes the seeds' harmful components, you should always take great care around castor bean plants or unprocessed seeds.
- Castor oil applied to the scalp can help to moisturize and protect the hair by sealing the hair fiber's outermost layer, known as the cuticle. This can help keep your hair healthy, giving it a better chance of achieving optimal natural growth. Excessive external use of castor oil can make your skin and hair oily, but there should be little to no risk of other potential side effects.
- In conjunction with moisturizing castor-oil treatments--or as an alternative to them--you can do a number of things to keep your hair healthy and create the best possible conditions for growth. Try to stay in good overall health by maintaining a balanced diet, exercising regularly, getting adequate sleep and avoiding smoking. Sticking to a regular hair care routine can also be helpful. In fact, consider giving yourself a scalp massage now and again while washing or conditioning your hair. This can increase blood flow to your scalp and stimulate hair follicles. If you decide to pursue any treatments or techniques that are more invasive or unusual, make a point of discussing your plans in advance with a doctor, pharmacist or hairstylist.
