Virasorb Virasorb contains the active ingredient aciclovir (5%), Virasorb & is a great value, antiviral cold sore cream. The earlier Virasorb is applied the greater the healing effect, if you can apply Virasorb before the cold sore appears it can be avoided all together. Ingredients The active ingredient is Aciclovir (5%). The other ingredients are Purified Water, Arlatone 983s, Cetyl Alcohol, Dimeticone, Propylene Glycol, White Petrolatum & Liquid Paraffin. Directions Adults: Apply five times daily for five days. May be continued for a further five days if necessary.