Q: Dear Dr. Mao,
I have been told that lemon balm is helpful for a cold sore. How effective is it?
A: More commonly known in the United States as lemon balm, Melissa officinalis is widely sold in Europe as a topical cream for the treatment of oral herpes. Early studies of melissa ointments showed a significant reduction in the duration and severity of herpes symptoms (both genital and oral) and, when the cream was used regularly, a marked reduction in the frequency of recurrences.
A recent study followed individuals who were just starting to develop a cold sore (oral herpes). Treatment with melissa cream produced significant benefits on day 2, reducing intensity of discomfort, number of blisters, and the size of the lesion. The researchers specifically looked at day 2 because, according to them, that is when symptoms are most pronounced. Furthermore, long-term follow-up suggested that use of melissa can prolong the interval before the next herpes flare-up.