-Lysine is an essential amino acid that must be obtained through the diet or through supplementation. Lysine is necessary for the production of all proteins in the body, and is required for the maintenance of the structural proteins collagen and elastin, which form all connective tissue such as skin, tendon, and bone. L-Lysine is also a precursor to L-carnitine, which is needed for fat metabolism and energy production, which can support good health. In addition, L-Lysine supports a healthy immune system helping to fight cold sores. Capsule delivery provides faster, more complete absorption. Our NOW natural and organic Supplements are an effective way to ensure you and your loved ones are getting essential vitamins, minerals and nutrients for daily optimal health. Since 1968, NOW has been making top quality products that are tested to the highest standards to empower people to lead healthier lives. Our promise - what is on the label, is precisely what is in the bottle.