Cold Sore Cream Tube With Aciclovir 5% is an effective treatment for Cold Sores. It contains the same active ingredient as Zovirax cream, to help treat the infection. Cold Sore Cream with Aciclovir 5% helps to treat the cold sore and gives you the much-needed relief. The best time to start this treatment is when the tingling sensation first happens, before any visible sign of a cold sore appears.