Acyclovir is available only on prescription. Therefore, you must consult your doctor before using it to treat a cold sore.
Tablet: For treating cold sores, the usual dose is one 200 mg tablet taken five times a day, spread across four hours. Generally, the suggested timings are 7 am, 11 am, 3 pm, 7 pm, and 11 pm.
Cream or ointment: If you use Acyclovir cream for cold sores, doctors will recommend using the specified amount five times a day.