**Castor Oil: Benefits, Side Effects, Uses, Dosage, Warnings?** Frankly, if you went to a pharmacy sore throat, castor oil would certainly be the last remedy you would ask. And if you did, you should expect reactions to say the least embarrassing. Yes, in case you did not know, castor oil is a powerful laxative. Castor oil At ... arm). Normally, the muscle fibers do not hurt. If you find a "node" painful, do it as a poultice over several days. They are easy to reach areas.