Licorice extract
Licorice root has become one of the most popular treatment options for blisters. A 2014 study showed that licorice has antiherpetic activity. However, its effects on the virus still need to be studied more. You can apply diluted licorice extract to your blister using a cotton swab or fingertips. Make the extract into a paste with coconut or almond oil and apply to the affected area. You can speak with your doctor before taking licorice root orally, because it can lead to unexpected side effects. Apply the licorice extract or paste different times and stop when the blister heals.