L 15 cream is significantly effective in reducing cold sore symptoms, blisters and itches. It contains L-Lysine, used for preventing and treating cold sores caused by the virus called herpes simplex labialis. Lysine is an essential amino acid, which is elementarily required by the body for proper bone, muscular, and overall growth.It helps in preventing the genital herpes outbreak and cold sores occurring around the mouth. L 15 cream, when regularly applied on the occurrence of a cold sore, can soothe and heal the annoying infections. This medication is also known to give an immediate relief to the atrocious sores in your mouth and cure it faster. Directions of use: Apply it to the sores by gently spreading it on the infected area,as directed by the physician. Use under medical supervision.