Commonly called by its Latin first name, Melissa, lemon balm is a native of southern Europe, often planted in gardens to attract bees. Its leaves give off a delicate lemon odor when bruised.

Medical authorities of ancient Greece and Rome mentioned topical lemon balm as a treatment for wounds. The herb was later used orally as a treatment for influenza, insomnia, anxiety, depression, and nervous stomach.

Topical lemon balm is most popular today as a treatment for genital or oral herpes. It appears to make flare-ups less intense and last for a shorter period of time, but it doesn't completely eliminate them. Regular use of lemon balm might help prevent flare-ups, but this potential use hasn’t been properly studied.

Note: While conventional treatments can reduce infectivity and thereby help prevent the spread of herpes, there is no evidence as yet that lemon balm offers this benefit. Keep in mind also that common sense methods of avoiding passing on herpes are not entirely effective: Many people are infectious even when they do not have obvious symptoms, and use of a condom does not entirely prevent the spread of the virus. Therefore, if you are sexually active with a noninfected partner who wishes to remain that way, we strongly recommend that you use suppressive drug therapy.

There is some evidence that oral use of lemon balm has sedative effects, and it is currently used for insomnia, anxiety, nervous stomach. There is also some evidence that it may be helpful incolic, and irritable bowel syndrome. Inhaled essential oil of lemon balm may also have calming effects.