Lysine is an essential amino acid, meaning we cannot make it but must get it directly from our diet. It’s an important nutrient that helps to make proteins for the body, like muscles and tissues, plus aids in making collagen in our connective tissues strong and flexible. It also helps our uptake and utilization of minerals like calcium and iron and helps with fatty acid metabolism by making carnitine. It helps regulate the external effects on our genes through histone modification. That’s a lot of benefits for one little amino acid!
One of the other well-known benefits of lysine is in its role with cold sore symptoms. Herpes simplex virus (HSV), the virus responsible for cold sores, naturally contains more of the amino acid arginine and less lysine. Since lysine and arginine compete for absorption and uptake, lysine supplementation is used as a treatment to take up these spaces in these viral cells, decreasing their ability to function. Taking supplemental L-lysine can decrease the frequency and duration of cold sore outbreaks