The essential oil of the rosemary herb is steam distilled from flowers, stems and leaves of the plant. According to the British Pharmacopoeia, the oil is distilled from the flowering tops is superior to that obtained from the stem and leaves Extraction Method: The smell of rosemary essential oil is woody and herbal and is used in aromatherapy to refresh and stimulate the mind. What's in the box 1 x 10ml Dropper Bottle