Jamaican black castor oil is derived from Jamaican castor beans. It is believed to support hair growth by ridding the scalp of damaging fungi and toxins. It also works to hydrate hair and skin by locking in moisture. Benefits of Jamaican Black Castor Oil Promote Respiratory Health. ... Improve Hair Health. ... Enhance Skin Health. ... Promote Hair Growth. ... Moisturize Dry Hair. ... Strengthen Hair. ... Prevent Hair Breakage. ... Heal and Prevent Split Ends. it treats dandruff, moisturizes hair, promotes hair growth, treats acne, and even relieves muscle pain.