Lysine supplements protect and help treat cold sores. A frequent occurrence can mean infection, and they often get painful, too, if left untreated. If they frequently occur, taking L-Lysine can help. It is also known to eliminate the chances of blocked receptors involved in stress response. It also helps to increase calcium absorption in the gut and improves wound healing to a great extent. Some other smaller benefits include fatigue, irritability, nausea, red eyes, poor concentration, hair loss, anorexia, inhibited growth, anaemia, and helping with problems of the reproductive system. It is also useful in treating herpes, low blood pressure, diabetes, anxiety and supports hair growth too.