Rosemary essential oil is often used for alertness and stimulating memory. Dap a little into a handkerchief or cotton ball and inhale as needed. It can also keep you alert during long car trips or a long day at work. You Might Also Like Peppermint oil helps prevent muscle spasms. December 7, 2014 Olive leaf November 18, 2013 Castor oil speeds the healing of insect stings June 21, 2014