Rosemary is a herb. It is native to the Mediterranean region but is now grown worldwide. The leaf and its oil are used to make medicine.
Rosemary is used for improving memory, indigestion (dyspepsia), arthritis-related joint pain, hair loss, and other conditions, but there is no good scientific evidence to support most of these uses.
In foods, rosemary is used as a spice. The leaf and oil are used in foods, and oil is used in beverages.