What is Lysine?

Lysine, often abbreviated as K or Lys, is one of eight essential amino acids needed to build human proteins. Lysine cannot be naturally synthesised within the body and must be sourced from food or dietary supplements. As a protein building block, lysine is required for normal growth and development. Unlike many other amino acids, lysine is vital for the formation of all proteins needed by the human body.

This amino acid is particularly important for the manufacture of carnitine. This compound is needed to produce energy through the conversion of fatty acids. Lysine also helps in collagen formation and calcium absorption, both vital for bone and muscle health. Furthermore, lysine helps to regulate nitrogen within the body and supports lean body mass. Many hormones, antibodies and enzymes also require lysine.

Lysine Benefits

This essential amino acid has been extensively studied and is involved in many vital processes within the body. Below we have outlined some many health benefits offered by lysine.

Lysine helps to generate a positive nitrogen balance within the body. This allows the body to stay within a muscle building phase. When the muscles are stressed, such as a result of weight training, lysine helps to protect the muscle tissue. Lysine also assists with tissue repair, making it an important amino acid in the recovery from sporting injuries. Bodybuilders and other athletes often take lysine alongside other amino acids such as arginine and BCAAs (branch-chain amino acids) to maximise muscle synthesis, reduce fatigue and improve recovery times.

Lysine is very important for building and maintaining healthy bones. It helps to form collagen, which is an essential protein for building tendons, cartilage and bones. This amino acid also promotes calcium absorption and reduces the removal of calcium within urine. As calcium is essential for healthy bones, researchers have investigated the importance of lysine in treating and preventing bone loss in individuals suffering from osteoporosis.

One particular study evaluating the benefits of lysine on bone health treated women affected by osteoporosis with 800 mg of lysine per day. Researchers discovered that calcium absorption improved and bone mass increased following supplementation (http://www.ncbi.nlm.nih.gov/pubmed/1486246). Lysine supplementation is often recommended for post-menopausal women to help with calcium absorption and to strengthen and maintain bone mass.

Heart disease is caused by the build up of atherosclerotic plague (cholesterol) on the walls of blood vessels. One particular type of cholesterol known as lipoprotein(a), is the principal cause of atherosclerotic plague. It’s formed in the liver and is very sticky, allowing it to easily bind to vessel walls and attract other deposits. This build up is has been linked to low vitamin C levels. However, lysine can bind with lipoprotein(a) and stop these fatty deposits. Together with vitamin C, lysine supplementation is important in the prevention of cardiovascular diseases.

Research has also shown that lysine is important in treating the pain associated with angina pectoris. Patients suffering from angina experience a significant reduction in symptoms when taking lysine and vitamin C supplements (http://orthomolecular.org/library/jom/1993/pdf/1993-v08n02-p077.pdf, http://orthomolecular.org/library/jom/1993/pdf/1993-v08n03-p137.pdf).

Lysine supplementation is often used to treat a range of viral infection such as shingles, cold sores, herpes simplex, and human papilloma virus (HPV) illnesses such as genital herpes and genital warts. Many clinical trials have shown that the incidence of herpes can be significantly reduced in association with lysine supplementation and a low-arginine, high-lysine diet (http://ukpmc.ac.uk/abstract/MED/6435961, http://jac.oxfordjournals.org/content/12/5/489.short, http://www.ncbi.nlm.nih.gov/pubmed/3115841). Lysine helps to combat these viruses by reducing the metabolism of the amino acid arginine. Arginine is needed to support the replication of the herpes virus and make it active.

Lysine is required for the synthesis of carnitine. This substance is essential for the transport of fatty acids into the mitochondria to produce energy. Studies have shown that carnitine can reduce fat deposits, particularly subcutaneous and visceral fat (http://www.ncbi.nlm.nih.gov/pubmed/21745528). Lysine supplementation together with regular exercise and muscle building routines can help support weight loss.

As lysine is important in the building of muscle protein, this amino acid can also assist in the recovery following injury or surgery. Also, because lysine is required for collagen formation, it can help support healthy skin and hair. Consequently, lysine is often included within cosmetics to help combat the visible signs of aging. Lysine is also important for male fertility because it’s needed to synthesis carnitine, which improves sperm motility and health. Lysine also has anti-inflammatory properties and helps to relieve migraines, as well as other types of pain.

Lysine Deficiency

A deficiency in lysine can lead to a range of health problems such as reduced thyroid hormone production, chronic viral infections, kidney stone formation, asthma, and abnormal growth and development. Symptoms related to lysine deficiency include fatigue, dizziness, nausea, hair loss, enzyme disorders, retarded growth, loss of appetite and anaemia.

Lysine deficiencies are rare because this protein is found in so many food sources. However, vegetarians or vegans only using grain as a protein source can find that they are defiant in lysine. Individuals suffering from cold sores and herpes, as well as athletes and surgery patients can benefit from a higher intake of lysine.

Sources of Lysine

Good sources of this amino acid are found within eggs, cheese, milk, brewer’s yeast, pears, mangos, apricots, apples, bananas, legumes, seaweed, celery, beans, potatoes, peas, cauliflower, nuts (particularly cashews, Brazil nuts, pecans, walnuts and almonds), red meat, poultry, shellfish, and fish (particularly sardines, flounder and cod).

There are also a range of nutritional supplements available in the form of capsules, tablets and liquids that can be used to boost lysine levels. It’s important to consult a medical practitioner before taking supplements to determine appropriate dosage and to make sure that they won’t negatively interfere with any other medical condition.


Of the eight essential amino acids needed by the body, lysine is one of the most important because it’s required for the synthesis of all proteins. This amino acid can help in the prevention and treatment of diseases such as osteoporosis and cardiovascular problems. It’s also essential in the fight against viral infections such as herpes.

For bodybuilders and other athletes, lysine helps the body syntheses muscle tissue. It also assists in healing injuries and reduces the recovery time following resistance training. Weight loss can also be promoted through lysine.

Undoubtedly lysine is vital for an array of functions within the body and important for general well-being. Eating a balanced diet including lysine-rich foods will ensure that the body has an adequate supply of this essential amino acid. Dietary supplements may also be helpful for individuals unable to gain enough lysine from their diet.