How effective is antiviral treatment for cold sores?

Cold sores are caused by herpes simplex virus and often begin with tingling or burning before blisters appear around the lips. Antiviral creams or tablets can limit viral activity during an episode. They do not remove the virus from the body, so cold sores can return. The benefit is usually greatest when treatment begins before the blister is fully developed; established sores may still need time to heal.

Start the recommended treatment as soon as your clinician or pharmacist advises, and follow the product directions. Wash your hands before and after touching the area, avoid picking the blister, and do not share lip products, utensils or towels. Avoid kissing and oral contact while a sore is present, because the virus can spread from the early tingling stage through healing.

Arrange medical advice if sores are frequent, unusually painful, extensive, slow to heal, or affecting eating and drinking. Seek prompt care for a sore near the eye, eye pain or light sensitivity, or signs of infection such as increasing warmth, swelling or pus. People with weakened immunity should ask for advice early in an episode.

Ask which antiviral form suits your episode, when to begin it at the tingling stage, and whether a recurring pattern calls for a prevention plan. Confirm how to reduce spread at home and which eye symptoms need urgent assessment.