Fame Drugs Rosemary Essential Oil derived from the leaves of the rosemary plant (Rosmarinus officinalis), a fragrant herb commonly used in cooking and traditional medicine. The oil is obtained through steam distillation, a process that extracts the volatile compounds from the rosemary leaves. Rosemary oil has a variety of potential benefits and uses, both in aromatherapy, rosemarry essential oil, rosemarry oil for hair care and topical application.