I realized after I sent my last post on Castor that there is so much more to tell about this amazing plant; and especially about the oil made from the seeds. So I must continue...
Castor oil is chakshushya or beneficial for the eyes. Put a drop in each eye before you go to bed to pull out dust and detritus. The next morning rinse your eyes with warm water to get rid of the impurities & stickiness. The oil will also pull out excess Pitta (heat and moisture) which is especially important when you spend all day at a screen or slaving over an open fire. You can also rub the oil on your feet; eyes and feet are related organs so this will help your eyes, soften and beautify your feet, and help you to feel grounded (great to do before bed!).
Castor plant is vrushya (good for re/productive health) and the oil is used in a couple of related ways. Menstrual cramps and clotting are eased with a teaspoon or 2 of oil taken nightly for the week preceding your period. Castor oil packs remedy cramps externally as the oil & heat soothe Vata & reduce the clamor of pain. Generously slather your abdomen with oil, cover with plastic wrap or an old towel then a hot water bottle. Hang out for half an hour.
Finally, internal and external use of Castor oil are beneficial in the last month of pregnancy (not earlier!). It makes joints and tissues more flexible and resilient and also has Ardho gamitwa or downward movement which assists in an easy and quick delivery.
Ayurveda says that Castor oil is beneficial to all tissues so can safely be used indefinitely. Even the FDA agrees; setting the level for regular use at a tablespoon a day. If you are inspired to try it start with 1/4 - 1/2 tsp a day at bedtime or before a meal (treating chronic constipation or skin issues for instance) then increase your dose until you get the desired results.
If someone you cook for is in need of Castor oil (but resistant to taking medicines) you can cook it into foods quite easily; just add it to your cooking oil. This is done widely in India to keep children eliminating regularly and free of parasites!