Blackmores Lyp-Sine helps to relieve symptoms of cold sores. Blackmores Lyp-Sineis a therapeutic dose of the amino acid lysine, which reduces the number of outbreaks of cold sores, relieves symptoms and reduces healing time of lesions. Features and benefits Contains vitamin C and zinc for the healing of lesions. Suitable for pregnancy at the reduced dose of 1 tablet per day. Lysine has been shown to reduce the number of outbreaks of cold sores. It can reduce the severity of the outbreak, and decrease the severity of symptoms such as itching, burning and pain. A cold sore develops when the herpes simplex virus is active and replicating itself. The virus uses large amounts of the amino acid arginine for this replication process. The amino acid lysine competes with arginine for absorption into cells and tissues.