Sunny Isle Jamaican Black Castor Oil Rosemary 4oz. Rosemary is a popular choice for massage, which can be attributed to its sweetness and freshness. Rosemary essential oil use has proved to be very effective in treating arthritis, gout, cramping of muscles, rheumatism and neuralgia etc. It is beneficial in relieving the tired muscles and also considered advantageous for improving the blood circulation. It plays a vital role in hair care. It protects the hair from the strong hold of dandruff. So for those of you who want a sweet, fresh scent on your skin and, or healthy hair, along with the effectiveness of Sunny Isle Jamaican Black Castor Oil, then this combination is just for you. Compared to other brands Sunny Isle's Jamaican Black Castor oil is darker because they roast their beans longer which produces more Ash Content in their oil than other oils on the market. Sunny Isle believes that more ash content increases the effectiveness of the oil.