Lysine is a type of amino acid. Amino acids are the building blocks used to make proteins. Lysine is considered an "essential" amino acid because it cannot be created by the body. Instead, lysine must be supplied by the diet. Common dietary sources of lysine include meat, fish, dairy, eggs, soy, and legumes.
Lysine comes in two distinct structural forms: L-lysine and D-lysine. L-lysine is the more common form of lysine. L-lysine is also the only form that is active within the body.
Good scientific evidence suggests that lysine may be useful for treating lysine deficiency and some metabolic disorders. Early research also suggests that lysine may promote calcium metabolism and bone formation, as well as aid in the treatment and prevention of herpes simplex virus. However, more high-quality research is needed in these areas.

Related Terms

3 H-lysine, [3H]lysine, 5-hydroxy-L-lysine, [6-14]lysine, 14C-lysine, 15A8-glycyl-tyrosyl-(N-epsilon-diethylenetriamine pentaacetic acid)-lysine, 15N-lysine, 24-h [13C]leucine, 320 lysine, 373 lysine, acetone/periodate-lysine-paraformaldehyde (PLP), AGEs, alginate-pectin-poly-L-lysine, alginate-poly(L)lysine-alginate membrane, alpha-N-acetyl-L-lysine anilides, alpha-N-acetyl-L-lysine methyl ester, alpha-N,N-bis[carboxymethyl]lysine, amino acid anabolism, amino acids, B lysine residue, bendazac lysine, beta 2 132 lysine, beta 59 (E3) lysine, beta 144 (HCl) lysine-asparagine, beta-lysine, bis-L-tyrosinyl-L-lysine, C6H14N2O2, carbocysteine lysine salt, carboxyethyl lysine, carboxyethyl-lysine, carboxyethyllysine, carboxymethyl lysine, carboxymethyl-lysine, carboxymethyllysine, carboxy-terminal lysine, cdc2 lysine 33, cefuroxime lysine, CEL, CML, C-terminal lysine, dansyl lysine, decarboxylate lysine, desglycinamide lysine vasopressin, di-lysine, dipalmityl lysine group, DNA-lysine, E-N-trimethyl-lysine, epsilon-amino-carbamoyl-lysine, epsilon-diaminocaproic acid, epsilon-DNP-lysine, epsilon(gamma-glutamyl) lysine, epsilon-lysine (poly)peptides, epsilon-N-DL-trimethyl-lysine, epsilon-N(L-furoylmethyl)-L-lysine, epsilon-N-methyl lysine, epsilon-N-trimethyl-lysine, furosine, galactosylated poly-L-lysine, glutamic acid-lysine (EK), glycyl-L-histidyl-L-lysine, H3-lysine, H-D-valyl-L-leucyl-L-arginine 4-nitroanilide, H-D-valyl-L-leucyl-L-lysine 4-nitroanilide, hippuryl-lysine, histone H3 lysine 9, histone H3 lysine 27, histone lysine methyl transfer, homocitrulline, isopeptide, ketoprofen lysine, L-[1-13C]lysine, L-[13C1]lysine, L-[15N2]lysine, lactosylated poly-L-lysine, L-[alpha-15N]lysine, LC, L-lysine, L-lysine amidotrizoate, L-lysine diatrizoate, L-lysine monohydrochloride, L-lysine-alpha-oxidase, L-N6-(1-iminoethyl)lysine, LVP, Lys, Lys-5, Lys-33, (Lys-43), Lys-60f, Lys-63 polyUb chains, Lys-77, Lys-122, Lys-128, Lys-129, Lys-156, Lys-192, Lys-234, Lys-236, Lys-284, Lys-286, Lys-287, Lys K, lysine analog (MK-521), lysine analogs [aminocaproic acid and tranexamic acid], lysine epsilon-amino groups, lysine palmitoylation, lysine residue 162, lysine residue 340, lysine salt, lysine (solusprin), lysine-5, lysine-8-vasopressin, lysine-20, lysine-29, lysine-41, lysine-43, lysine-48, lysine-49 phospholipase A2, lysine-49 phospholipase A2 isoform, lysine-50, lysine-54, lysine-60f, lysine-63, lysine-70, lysine-72, lysine-75, lysine-77, lysine-79, lysine-92, lysine-121, lysine-125, lysine-134, lysine-149, lysine-156, lysine-158, lysine-160, lysine-182, lysine-183, lysine-185, lysine-192, lysine-199, lysine-204, lysine-205, lysine-271, lysine-304, lysine 405, lysine-416, lysine-460, lysine-532, lysine-539, lysine-743, lysine-851, lysine-893, lysine-950, lysine-acetyl salicylate, lysine-acetylsalicylate (L-ASA), lysine-acetylsalicylic acid, lysine-aminopeptidase, lysine-clonixinate (CAS 55837-30-4), lysine-decarboxylase, lysine-fosfomycin, lysine-gingipain protease (Kgp), lysine-hydrochloride, lysine-hynic conjugate Fmoc-N-epsilon-(Hynic-Boc)-Lys, lysine-ketoglutarate, lysine-MDA [3-(N epsilon-lysino)propan-1-ol (LM)], lysine-MDA-lysine iminopropene cross-link [1,3-di(N epsilon-lysino)propane (LML) and lysine-HNE [3-(N epsilon-lysino)-4-hydroxynonan-l-ol (LHNE)], lysine-monohydrochloride, lysine-para-isobutylphenyl propionate, lysine-phenylalanine-glutamate-arginine-glutamine (KFERQ), lysine-p-isobutylphenylpropionate, lysine-p-isobutyl-phenylpropionate, lysine-salicylate, lysine-sepharose, lysine-sepharose 4B, lysine-specific cysteine proteinase, lysine-theophylline, Lys-plasminogen, lysyl oxidase, lysyl-L-lysine, mafosfamide lysine (ASTA-Z 7654), malondialdehyde-lysine, (MDA-lysine), MDP-Lys (L18), methylated lysine, methyl-lysine marks, metrecal arginine lysine, muroctasin, N-acetylglycyl-lysine methylesterhydrolase, N2-acetyl-N6-dinitrophenyl-lysine, N2-/(N-acetylmuramoyl)-L-alanyl-D-isoglutaminyl/-N6-stearoyl-L-lysine(MD P-Lys (L18)), N6-(iminoethyl)-L-lysine, N15 lysine, N(alpha)-(5'-phosphopyridoxyl)-L-lysine, N-alpha-benzyloxycarbonyl-L-lysine thiobenzyl ester (BLT), N-alpha-benzyloxycarbonyl-L-lysine thiobenzyl ester serine esterase, N-alpha-Fmoc-L-lysine, N-alpha-(gamma-aminobutyryl) lysine, N-alpha-p-tosyl-L-lysine chloromethylketone, N-alpha-triglycyl-(8-lysine)-vasopressin and 8-lysine-vasopressin, N-(epsilon)-(1-carboxyethyl)lysine, N-epsilon-(carboxyethyl)lysine (CEL), N-epsilon-(carboxymethyl)lysine (CML), N-epsilon-gamma-glutamyl lysine, N-(epsilon)-(gamma-glutamyl)lysine isodipeptide, N-(epsilon)-(gamma-L-glutamyl)-L-lysine (GGEL), N-epsilon-methylated lysine, N-epsilon-[(R)-1-carboxyethyl]-L-lysine (alaninolysine, AlaLys), N-(epsilon)-[(R)-1-carboxyethyl]-N(alpha)-(D-galacturonoyl)-L-lysine, N-iminoethyl-L-lysine, negative lysine decarboxylase, peptidyl lysine, periodate-lysine-paraformaldehyde (PLP), phenylalanine-2-lysine-8-vasopressin, p-isobutylphenylpropionate of lysine, PLL, PLP, poly-alpha-lysine (alpha-PL), poly-D-lysine, poly(epsilon-L-lysine), poly-epsilon-lysine (epsilon-PL), polyinosinic-polycytidylic lysine carboxymethylcellulose (poly(ICLC)), poly-L-lysine, poly(L-lysine), poly-L-lysine polymers, poly(L-lysine)-diethylenetriaminepentaacetic acid carrier, polylysine, polyriboinosinic-polyribocytidylic acid-poly-L-lysine complex (poly(ICL)), pronyl-lysine, RN-56-87-1 (lysine), rociverin-lysine acetylsalicylate, (S)-2,6,-diaminohexanoic acid, sepharose-L-lysine, strepronine-lysine salt, tetracyline-L-methylene lysine (Tetralysal), tetra-L-lysine, thiolated poly-L-lysine (PLL), triglycyl lysine vasopressin (glypressin), valyl-leucyl-lysine 4-nitroanilide, xylose lysine desoxycholate agar.
Note: This summary does not include lysine clonixinate. The terms lysine and L-lysine are used interchangeably throughout.

evidence table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Deficiency (lysine) (Grade: A)
Strong evidence suggests that lysine is needed for growth and development, protein synthesis, and calcium absorption. The intake of inadequate lysine or excess arginine may both contribute to lysine deficiency. Symptoms of lysine deficiency include anemia (decreased red blood cells), dizziness, fatigue, nausea, bloodshot eyes, loss of appetite, and slow growth. With the exception of vegans and some athletes, lysine deficiency is rare in most people.
Metabolic disorders (lysinuric protein intolerance) (Grade: B)
Lysinuric protein intolerance (LPI) is a genetic condition whereby the absorption of various amino acids, including lysine, is impaired. Some evidence suggests that lysine supplementation may improve lysine levels in people with LPI. More high-quality research is needed in this area.
Canker sores (Grade: C)
Contrary to popular belief, canker sores are not caused by the herpes simplex virus. Early research, however, suggests that canker sores may be linked to lysine status. Further research is need in this area.
Childhood growth promotion (Grade: C)
Some research has examined the effects of lysine on the growth and development of healthy children. Further research is needed in this area before any conclusions may be made.
Eye disorders (gyrate atrophy) (Grade: C)
Gyrate atrophy is an eye disorder whereby the retina degrades due to an abnormally high level of the amino acid ornithine. Limited research suggests that lysine may reduce excess ornithine. Further research is needed in this area.
Herpes virus (Grade: C)
Early research suggests that lysine may be effective in treating and preventing repeated symptom flares of viral herpes. Due to conflicting findings, more high-quality research is needed in this area before any firm conclusions may be made.
Stress (Grade: C)
Limited research suggests that lysine may play a role in reducing stress and anxiety. Further research is needed in this area before any conclusions may be made.
Type 2 diabetes (Grade: C)
Some research suggests that lysine may improve blood sugar levels and insulin activity in people with type 2 diabetes. Due to conflicting findings, more high-quality research is needed in this area before any firm conclusions may be made.
Metabolic disorders (alkalosis) (Grade: D)
Robust scientific evidence is currently lacking to support the use of lysine in the treatment of metabolic alkalosis. Metabolic alkalosis is a type of pH (acid-base) imbalance, whereby the body is too alkaline (basic). Some research suggests that lysine may worsen the alkaline imbalance in people at risk of metabolic alkalosis, such as those being fed via venous injection.
Strength enhancement (Grade: D)
According to available research, evidence is lacking to suggest that amino acid supplementation or increased intake of dietary protein may contribute to enhanced muscle strength and power.