Infection with Herpes simplex virus type 1 (HSV-1) typically causes lesions of the mouth, face, skin, esophagus, or brain. Herpes simplex virus type 2 (HSV-2) usually causes infections of the genitals, rectum, skin, hands, or meninges. The herpes viruses are a major cause of blindness from keratitis. The usual drugs used for herpes are Vidarabine, Acyclovir, Penciclovir and Ganciclovir; they are associated with several complications. The aim of this study was to investigate if a formulation containing 2.5 mg melatonin and 100 mg SB-73 would help patients with herpes, and to compare the preparation with 200 mg Acyclovir. SB-73 is a mixture of magnesium, phosphate, fatty acids extracted from Aspergillus sp. which has anti-herpes virus properties. A single blind randomized study was performed in which 70 patients underwent treatment using the supplement cited above (group A) and 75 received treatment of 200 mg Acyclovir (group B). Sixty-seven patients of the group A (95.7%) reported a complete regression of symptoms after 7 days of treatment. By comparison, 64 subjects (85.3%) of the Acyclovir reported regression of symptoms in the same period. There was statiscally significant difference between the groups (P < 0.05).