A topic in Clinical Evidence summarizes the results of 12 RCTs on the treatment of recurrent herpes labialis attacks. Seven RCTs found that topical aciclovir reduced healing time compared with placebo. Two RCTs found that topical penciclovir reduced healing times. Five RCTs provided more limited evidence that aciclovir or penciclovir reduced pain. Four RCTs assessed oral antiviral agents. The first RCT (n=174) found that oral aciclovir 400 mg 5 times daily for 5 days taken early (when the person first experienced tingling) reduced symptoms compared with placebo (8.1 days vs 12.5 days, p=0.02). The second RCT (n=149) found no significant difference in healing time (7.78 days vs 8.64 days). The third and fourth RCTs (n=902 and 954) found that oral valaciclovir for 1 day (2 g twice daily) or for 2 days (2 g twice daily for the first day and 1 g twice daily for the second day) reduced median duration of episode (5.0 days vs 5.0 days vs 5.5 days, p<0.001).