Parsley contains a large amount of chlorophyll, and as such is a natural breath sweetener. Eat the leaves right off the plant to combat breath odors.
Throughout history, Parsley teas have been used mainly as kidney stone, bladder infection, and jaundice medications, as well as digestive aids. The root appears to be more effective than the leaves, but leaves can also be used. Leaves can be dried, pulverized into a powder, and inserted in capsules, if desired. See the link below for more information. Pregnant women should avoid all but small quantities of Parsley because it can be irritating to the kidneys.
Externally, make an oil of Parsley leaves and roots to repel head lice, and an ointment for use on swellings. Pound the leaves into a paste and mix with a little water or tea to use on skin for easing symptoms from bug bites and stings. A little oatmeal can be added to this mixture for better consistency. Try dipping a cloth in unsweetened tea and place over closed eyes for 10 minutes to reduce fatigue and swelling of the eyes.