Learn all about L-Lysine

L-lysine works in the body through several key actions. Its most well-known effect is against the herpes simplex virus (HSV), which causes cold sores. Lysine competes with another amino acid, arginine, for absorption and use by the body. HSV needs arginine to replicate; by increasing lysine levels, less arginine is available for the virus, slowing or stopping its multiplication. Lysine is also a fundamental building block for proteins, including collagen, the main structural protein in skin, bone, tendons, and cartilage. It's essential for the cross-linking process that gives collagen its strength and stability. Additionally, lysine is needed to make carnitine, a molecule that transports fatty acids into cells' power plants (mitochondria) to be burned for energy. Regarding bone health, lysine helps the body absorb calcium from the intestines and reduces how much calcium is lost in urine, helping to keep bones strong. Its potential effects on anxiety are thought to involve interactions with serotonin receptors in the brain; some research suggests lysine might act like a serotonin antagonist (blocker) at certain receptors, potentially reducing stress responses, but this is still being studied.

L-lysine is readily available in many protein-rich foods, especially animal products. Good sources include red meat, poultry (chicken, turkey), fish (like cod and sardines), eggs, and dairy products (milk, cheese, yogurt). For example, 100g of chicken breast provides about 3g of lysine, while 100g of Parmesan cheese offers around 2.5g. Plant-based sources generally contain less lysine, but good options include legumes (beans, lentils, peas, especially soybeans/tofu), quinoa, amaranth, pistachios, and pumpkin seeds. However, many grains like wheat and corn are relatively low in lysine, which is why combining grains with legumes (like rice and beans) is important in vegetarian diets to ensure a complete amino acid profile. While most people get enough lysine from a balanced diet, vegetarians, vegans, or those on very low-protein diets might need to pay closer attention to their intake. Supplemental lysine provides a concentrated dose, useful for specific goals like managing cold sores or if dietary intake is insufficient.