Mood and Stress: The aroma of rosemary alone has been linked to improving mood, clearing the mind, and relieving stress in those with chronic anxiety or stress hormone imbalances. When the plant is consumed or applied topically in some sort of salve of the leaves, it can have similar effects. Aromatherapy also uses rosemary essential oil for this purpose, but that concentration of active components isn’t necessary to have positive effects on stress and mood.