Lysine, an essential amino acid, is a key component of many of our body’s processes. It helps to create and maintain connective tissues, build proteins, absorb and use calcium, and repair damaged tissues. It is also involved in hormone, enzyme, and antibody production, as well as energy metabolism (Dorland, 2017).

Lysine is not produced by the body naturally, making it an essential nutrient that must be obtained from dietary sources. The Recommended Dietary Allowance (RDA) for lysine is 38 mg/kg bodyweight/day for adults. The primary dietary sources of lysine are animal proteins such as beef, pork, poultry, fish, eggs, dairy, and soy. Plant proteins such as legumes, whole grains, nuts, and seeds are also good sources of lysine, although not as good as animal proteins (USDA, 2020).

Research has found that lysine is important for growth and development, especially in children. It is also beneficial for the immune system and can help reduce the frequency of cold sores. Lysine has also been studied for its potential to improve athletic performance and reduce anxiety. Additionally, lysine supplements have been found to be effective in treating anemia caused by a deficiency in iron (Rocha et al., 2020).

Lysine is generally considered safe, with few side effects reported. However, large doses may cause abdominal pain, cramps, and diarrhea. Taking lysine with other supplements may also increase the risk of side effects. It is important to speak with your doctor before taking any supplement (Rocha et al., 2020).

In conclusion, lysine is an important essential amino acid that plays a role in many of our body’s processes. It is important to get enough lysine from dietary sources, as our bodies do not produce it naturally. Additionally, lysine supplements may be beneficial in certain situations, such as treating anemia or reducing cold sores. However, it is important to speak with your doctor before taking any supplement.


Dorland, W. A. (2017). Dorland’s Illustrated Medical Dictionary. Philadelphia: Elsevier.

Rocha, M., de Oliveira, P. B., de Souza, T. L., & de Oliveira, P. R. (2020). Lysine: A review of its potential use and efficacy in human health. Nutrients, 12(3), 781.

USDA (2020). USDA Food Composition Databases. Retrieved from

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