What's best to use on fever blister?

Acyclovir: You can ask your doctor for a prescription cream for Acyclovir to treat the skin lesions, if they erupted less than 48 hours ago, otherwise, they are going to take their course. You may need to treat the next outbreak early to prevent them from spreading.

Antiviral: Your Dr can prescribe oral valtrex or another antiviral medication. Laser txs are also used to treat cold sores. Melissa Officinalis or lemon balm (cream) expedite healing of cold sores. It can reduce healing time by 1/2. Studies also show that regular use can help v recurrences. Brief supplementation w lysine 1,000mg orally 3 times a day at onset, can also hasten healing.