14. Never use it on children under 2
This is another hard rule, and I won’t soften it. Do not use castor oil on children under age 2, whether on the skin, scalp, lashes, or by mouth. Their skin is more delicate, and the old oral remedy is especially inappropriate. The margin for irritation, accidental eye exposure, and swallowing is simply too narrow.
The one honest exception is none for home use. If a pediatric clinician has a specific recommendation using a specific product, that is different. But a household bottle from the cabinet is not something I would use on a child that young in any amount or on any schedule.
15. For hair, apply it to the scalp only, then wash it out within 2 hours
When people smear castor oil all over the hair shaft from roots to ends, they usually end up with a heavy, hard-to-remove coating. The better method is to part the hair and apply a small amount to the scalp only: about 1 teaspoon for a few targeted areas, or up to 1 tablespoon for the whole scalp, massaged in for 3 to 5 minutes. Then shampoo it out within 30 minutes to 2 hours. Two washes may be needed because this oil is so dense.
The exception is using the tiniest trace on dry ends after washing, but I mean tiny, as in a drop rubbed between the palms and touched only to the ends. For most people, the real value is at the scalp, not in saturating the full length of the hair until it clings like fryer grease.
Castor oil still has a place in an old-fashioned cabinet, but it works best when you stop treating it like a cure-all and start treating it like a strong, useful oil with rules. A few drops, the right spot, and the right timing will take you a lot farther than the old spoonful ever did.
