As 1 of 9 essential amino acids, l-lysine is a building block of protein commonly found in protein-rich foods like meats, eggs, beans, and cheese.
L-Lysine deficiencies may result in psychological and physiological problems.
Also, L-lysine is used for several medicinal purposes, and due to its chemical nature, several athletes supplement it to improve athletic performance parameters.
L-lysine is being studied for its effects on psychological health. One study indicates diets low in lysine may lead to higher stress and anxiety levels.
A 3-month, double-blind study analyzed lysine’s effects on chronic anxiety in test subjects. Researchers indicate lysine supplementation reduced chronic anxiety, which was measured by the train anxiety inventory in males.
When administered in combination with another amino acid l-arginine, l-lysine resulted in increased growth hormone secretion. Researchers indicate these results were reproducible; however, no human growth hormone response was noticed when each amino acid was administered alone.
L-lysine aids in calcium absorption leading researchers to believe it combats bone loss resulting from osteoporosis. Also, L-arginine and L-lysine combined increased activity of bone-forming cells.
Some studies reveal l-lysine may ameliorate flare-ups from herpes. Researchers found l-lysine administered every day over a 6-month period resulted in an average 2.4 less flare-ups than the placebo group.
During the study analyzing l-lysine’s effects on anxiety and stress, a dose of 4.2 g per kg of wheat flour was used.
A 1,200 mg l-lysine and 1,200 mg l-arginine combination was used during the human growth hormone study.
An online medical and academic authority indicates 12 mg/kg is a recommended daily amount for preventing deficiencies.
For combatting cold sores (herpes simplex labialis), medical authorities have used a 1,000 mg daily dose for 12 months and a 1,000 mg dose taken 3 times a day for 6 months.
-  Miro Smriga, et al. “Lysine fortification reduces anxiety and lessens stress in family members in economically weak communities in Northwest Syria.” PNAS Vol. 101 no. 22.
-  Isidori A, Lo Monaco A, Cappa M. “A study of growth hormone release in man after oral administration of amino acids.” Curr Med Res Opin. 1981;7(7):475-81.
-  “Lysine.” University of Maryland Medical Center.
-  Griffith RS, Walsh DE, Myrmel KH, et al. Success of L-lysine therapy in frequently recurrent herpes simplex infection. Treatment and prophylaxis.Dermatologica . 1987;175:183-190.
-  “Lysine.” WebMD.