Lysine (symbol Lys or K) is an α-amino acid that is a precursor to many proteins.
Lysine contains an α-amino group, an α-carboxylic acid group, and a side chain lysyl, classifying it as a basic, charged (at physiological pH), aliphatic amino acid.
IUPAC name: (2S)-2,6-Diaminohexanoic acid
CAS Number: 70-54-2
EC Number: 200-740-6
Chemical formula: C6H14N2O2
Lysine is encoded by the codons AAA and AAG.
Like almost all other amino acids, the α-carbon is chiral and lysine may refer to either enantiomer or a racemic mixture of both.
For the purpose of this article, lysine will refer to the biologically active enantiomer L-lysine, where the α-carbon is in the S configuration.
The human body cannot synthesize lysine.
Lysine is essential in humans and must therefore be obtained from the diet.
In organisms that synthesise lysine, two main biosynthetic pathways exist, the diaminopimelate and α-aminoadipate pathways, which employ distinct enzymes and substrates and are found in diverse organisms.
Lysine catabolism occurs through one of several pathways, the most common of which is the saccharopine pathway.
Lysine plays several roles in humans, most importantly proteinogenesis, but also in the crosslinking of collagen polypeptides, uptake of essential mineral nutrients, and in the production of carnitine, which is key in fatty acid metabolism.
Lysine is also often involved in histone modifications, and thus, impacts the epigenome.
The ε-amino group often participates in hydrogen bonding and as a general base in catalysis.
The ε-ammonium group is attached to the fourth carbon from the α-carbon, which is attached to the carboxyl group.
Due to its importance in several biological processes, a lack of lysine can lead to several disease states including defective connective tissues, impaired fatty acid metabolism, anaemia, and systemic protein-energy deficiency. In contrast, an overabundance of lysine, caused by ineffective catabolism, can cause severe neurological disorders.
Lysine was first isolated by the German biological chemist Ferdinand Heinrich Edmund Drechsel in 1889 from the protein casein in milk.
He named it "lysin".
In 1902, the German chemists Emil Fischer and Fritz Weigert determined lysine's chemical structure by synthesizing it.
Biosynthesis of Lysine:
Two pathways have been identified in nature for the synthesis of lysine.
The diaminopimelate (DAP) pathway belongs to the aspartate derived biosynthetic family, which is also involved in the synthesis of threonine, methionine and isoleucine.
Whereas the α-aminoadipate (AAA) pathway is part of the glutamate biosynthetic family.
The DAP pathway is found in both prokaryotes and plants and begins with the dihydrodipicolinate synthase (DHDPS) (E.C 4.3.3.7) catalysed condensation reaction between the aspartate derived, L-aspartate semialdehyde, and pyruvate to form (4S)-4-hydroxy-2,3,4,5-tetrahydro-(2S)-dipicolinic acid (HTPA).
The product is then reduced by dihydrodipicolinate reductase (DHDPR) (E.C 1.3.1.26), with NAD(P)H as a proton donor, to yield 2,3,4,5-tetrahydrodipicolinate (THDP).
From this point on, four pathway variations have been found, namely the acetylase, aminotransferase, dehydrogenase, and succinylase pathways.
Both the acetylase and succinylase variant pathways use four enzyme catalysed steps, the aminotransferase pathway uses two enzymes, and the dehydrogenase pathway uses a single enzyme.
These four variant pathways converge at the formation of the penultimate product, meso‑diaminopimelate, which is subsequently enzymatically decarboxylated in an irreversible reaction catalysed by diaminopimelate decarboxylase (DAPDC) (E.C 4.1.1.20) to produce L-lysine.
The DAP pathway is regulated at multiple levels, including upstream at the enzymes involved in aspartate processing as well as at the initial DHDPS catalysed condensation step.
Lysine imparts a strong negative feedback loop on these enzymes and, subsequently, regulates the entire pathway.
The AAA pathway involves the condensation of α-ketoglutarate and acetyl-CoA via the intermediate AAA for the synthesis of L-lysine.
This pathway has been shown to be present in several yeast species, as well as protists and higher fungi.
It has also been reported that an alternative variant of the AAA route has been found in Thermus thermophilus and Pyrococcus horikoshii, which could indicate that this pathway is more widely spread in prokaryotes than originally proposed.
The first and rate-limiting step in the AAA pathway is the condensation reaction between acetyl-CoA and α‑ketoglutarate catalysed by homocitrate-synthase (HCS) (E.C 2.3.3.14) to give the intermediate homocitryl‑CoA, which is hydrolysed by the same enzyme to produce homocitrate.
Homocitrate is enzymatically dehydrated by homoaconitase (HAc) (E.C 4.2.1.36) to yield cis-homoaconitate.
HAc then catalyses a second reaction in which cis-homoaconitate undergoes rehydration to produce homoisocitrate.
The resulting product undergoes an oxidative decarboxylation by homoisocitrate dehydrogenase (HIDH) (E.C 1.1.1.87) to yield α‑ketoadipate.
AAA is then formed via a pyridoxal 5′-phosphate (PLP)-dependent aminotransferase (PLP-AT) (E.C 2.6.1.39), using glutamate as the amino donor.
In fungi, AAA is reduced to α‑aminoadipate-semialdehyde via AAA reductase (E.C 1.2.1.95) in a unique process involving both adenylation and reduction that is activated by a phosphopantetheinyl transferase (E.C 2.7.8.7).
Once the semialdehyde is formed, saccharopine reductase (E.C 1.5.1.10) catalyses a condensation reaction with glutamate and NAD(P)H, as a proton donor, and the imine is reduced to produce the penultimate product, saccharopine.
The final step of the pathway in fungi involves the saccharopine dehydrogenase (SDH) (E.C 1.5.1.8) catalysed oxidative deamination of saccharopine, resulting in L-lysine.
In a variant AAA pathway found in some prokaryotes, AAA is first converted to N‑acetyl-α-aminoadipate, which is phosphorylated and then reductively dephosphorylated to the ε-aldehyde.
The aldehyde is then transaminated to N‑acetyllysine, which is deacetylated to give L-lysine.
However, the enzymes involved in this variant pathway need further validation.
Catabolism of Lysine:
Like all amino acids, catabolism of lysine is initiated from the uptake of dietary lysine or from the breakdown of intracellular protein.
Catabolism is also used as a means to control the intracellular concentration of free lysine and maintain a steady-state to prevent the toxic effects of excessive free lysine.
There are several pathways involved in lysine catabolism but the most commonly used is the saccharopine pathway, which primarily takes place in the liver (and equivalent organs) in animals, specifically within the mitochondria.
This is the reverse of the previously described AAA pathway.
In animals and plants, the first two steps of the saccharopine pathway are catalysed by the bifunctional enzyme, α-aminoadipic semialdehyde synthase (AASS), which possess both lysine-ketoglutarate reductase (LKR) (E.C 1.5.1.8) and SDH activities, whereas in other organisms, such as bacteria and fungi, both of these enzymes are encoded by separate genes.
The first step involves the LKR catalysed reduction of L-lysine in the presence of α-ketoglutarate to produce saccharopine, with NAD(P)H acting as a proton donor.
Saccharopine then undergoes a dehydration reaction, catalysed by SDH in the presence of NAD+, to produce AAS and glutamate.
AAS dehydrogenase (AASD) (E.C 1.2.1.31) then further dehydrates the molecule into AAA.
Subsequently, PLP-AT catalyses the reverse reaction to that of the AAA biosynthesis pathway, resulting in AAA being converted to α-ketoadipate.
The product, α‑ketoadipate, is decarboxylated in the presence of NAD+ and coenzyme A to yield glutaryl-CoA, however the enzyme involved in this is yet to be fully elucidated.
Some evidence suggests that the 2-oxoadipate dehydrogenase complex (OADHc), which is structurally homologous to the E1 subunit of the oxoglutarate dehydrogenase complex (OGDHc) (E.C 1.2.4.2), is responsible for the decarboxylation reaction.
Finally, glutaryl-CoA is oxidatively decarboxylated to crotonyl-CoA by glutaryl-CoA dehydrogenase (E.C 1.3.8.6), which goes on to be further processed through multiple enzymatic steps to yield acetyl-CoA; an essential carbon metabolite involved in the tricarboxylic acid cycle (TCA).
Nutritional value of Lysine:
Lysine is an essential amino acid in humans.
The human daily nutritional requirement varies from ~60 mg/kg in infancy to ~30 mg/kg in adults.
This requirement is commonly met in a western society with the intake of lysine from meat and vegetable sources well in excess of the recommended requirement.
In vegetarian diets, the intake of lysine is less due to the limited quantity of lysine in cereal crops compared to meat sources.
Given the limiting concentration of lysine in cereal crops, it has long been speculated that the content of lysine can be increased through genetic modification practices.
Often these practices have involved the intentional dysregulation of the DAP pathway by means of introducing lysine feedback-insensitive orthologues of the DHDPS enzyme.
These methods have met limited success likely due to the toxic side effects of increased free lysine and indirect effects on the TCA cycle.
Plants accumulate lysine and other amino acids in the form of seed storage proteins, found within the seeds of the plant, and this represents the edible component of cereal crops.
This highlights the need to not only increase free lysine, but also direct lysine towards the synthesis of stable seed storage proteins, and subsequently, increase the nutritional value of the consumable component of crops.
While genetic modification practices have met limited success, more traditional selective breeding techniques have allowed for the isolation of "Quality Protein Maize", which has significantly increased levels of lysine and tryptophan, also an essential amino acid.
This increase in lysine content is attributed to an opaque-2 mutation that reduced the transcription of lysine-lacking zein-related seed storage proteins and, as a result, increased the abundance of other proteins that are rich in lysine.
Commonly, to overcome the limiting abundance of lysine in livestock feed, industrially produced lysine is added.
The industrial process includes the fermentative culturing of Corynebacterium glutamicum and the subsequent purification of lysine.
Dietary sources of Lysine:
Good sources of lysine are high-protein foods such as eggs, meat (specifically red meat, lamb, pork, and poultry), soy, beans and peas, cheese (particularly Parmesan), and certain fish (such as cod and sardines).
Lysine is the limiting amino acid (the essential amino acid found in the smallest quantity in the particular foodstuff) in most cereal grains, but is plentiful in most pulses (legumes).
Beans contain the lysine that maize lacks, and in the human archeological record beans and maize often appear together, as in the Three Sisters: beans, maize, and squash.
A food is considered to have sufficient lysine if it has at least 51 mg of lysine per gram of protein (so that the protein is 5.1% lysine).
L-lysine HCl is used as a dietary supplement, providing 80.03% L-lysine.
As such, 1 g of L-lysine is contained in 1.25 g of L-lysine HCl.
Biological roles of Lysine:
The most common role for lysine is proteinogenesis. Lysine frequently plays an important role in protein structure.
Since its side chain contains a positively charged group on one end and a long hydrophobic carbon tail close to the backbone, lysine is considered somewhat amphipathic.
For this reason, lysine can be found buried as well as more commonly in solvent channels and on the exterior of proteins, where it can interact with the aqueous environment.
Lysine can also contribute to protein stability as its ε-amino group often participates in hydrogen bonding, salt bridges and covalent interactions to form a Schiff base.
A second major role of lysine is in epigenetic regulation by means of histone modification.
There are several types of covalent histone modifications, which commonly involve lysine residues found in the protruding tail of histones.
Modifications often include the addition or removal of an acetyl forming acetyllysine or reverting to lysine, up to three methyl, ubiquitin or a sumo protein group.
The various modifications have downstream effects on gene regulation, in which genes can be activated or repressed.
Lysine has also been implicated to play a key role in other biological processes including; structural proteins of connective tissues, calcium homeostasis, and fatty acid metabolism.
Lysine has been shown to be involved in the crosslinking between the three helical polypeptides in collagen, resulting in its stability and tensile strength.
This mechanism is akin to the role of lysine in bacterial cell walls, in which lysine (and meso-diaminopimelate) are critical to the formation of crosslinks, and therefore, stability of the cell wall.
This concept has previously been explored as a means to circumvent the unwanted release of potentially pathogenic genetically modified bacteria.
It was proposed that an auxotrophic strain of Escherichia coli (X1776) could be used for all genetic modification practices, as the strain is unable to survive without the supplementation of DAP, and thus, cannot live outside of a laboratory environment.
Lysine has also been proposed to be involved in calcium intestinal absorption and renal retention, and thus, may play a role in calcium homeostasis.
Finally, lysine has been shown to be a precursor for carnitine, which transports fatty acids to the mitochondria, where they can be oxidised for the release of energy.
Carnitine is synthesised from trimethyllysine, which is a product of the degradation of certain proteins, as such lysine must first be incorporated into proteins and be methylated prior to being converted to carnitine.
However, in mammals the primary source of carnitine is through dietary sources, rather than through lysine conversion.
In opsins like rhodopsin and the visual opsins (encoded by the genes OPN1SW, OPN1MW, and OPN1LW), retinaldehyde forms a Schiff base with a conserved lysine residue, and interaction of light with the retinylidene group causes signal transduction in color vision.
Disputed roles of Lysine:
There has been a long discussion that lysine, when administered intravenously or orally, can significantly increase the release of growth hormones.
This has led to athletes using lysine as a means of promoting muscle growth while training, however, no significant evidence to support this application of lysine has been found to date.
Because herpes simplex virus (HSV) proteins are richer in arginine and poorer in lysine than the cells they infect, lysine supplements have been tried as a treatment.
Since the two amino acids are taken up in the intestine, reclaimed in the kidney, and moved into cells by the same amino acid transporters, an abundance of lysine would, in theory, limit the amount of arginine available for viral replication.
Clinical studies do not provide good evidence for effectiveness as a prophylactic or in the treatment for HSV outbreaks.
In response to product claims that lysine could improve immune responses to HSV, a review by the European Food Safety Authority found no evidence of a cause–effect relationship.
The same review, published in 2011, found no evidence to support claims that lysine could lower cholesterol, increase appetite, contribute to protein synthesis in any role other than as an ordinary nutrient, or increase calcium absorption or retention.
Roles in disease:
Diseases related to lysine are a result of the downstream processing of lysine, i.e. the incorporation into proteins or modification into alternative biomolecules.
The role of lysine in collagen has been outlined above, however, a lack of lysine and hydroxylysine involved in the crosslinking of collagen peptides has been linked to a disease state of the connective tissue.
As carnitine is a key lysine-derived metabolite involved in fatty acid metabolism, a substandard diet lacking sufficient carnitine and lysine can lead to decreased carnitine levels, which can have significant cascading effects on an individual's health.
Lysine has also been shown to play a role in anaemia, as lysine is suspected to have an effect on the uptake of iron and, subsequently, the concentration of ferritin in blood plasma.
However, the exact mechanism of action is yet to be elucidated.
Most commonly, lysine deficiency is seen in non-western societies and manifests as protein-energy malnutrition, which has profound and systemic effects on the health of the individual.
There is also a hereditary genetic disease that involves mutations in the enzymes responsible for lysine catabolism, namely the bifunctional AASS enzyme of the saccharopine pathway.
Due to a lack of lysine catabolism, the amino acid accumulates in plasma and patients develop hyperlysinaemia, which can present as asymptomatic to severe neurological disabilities, including epilepsy, ataxia, spasticity, and psychomotor impairment.
The clinical significance of hyperlysinemia is the subject of debate in the field with some studies finding no correlation between physical or mental disabilities and hyperlysinemia.
In addition to this, mutations in genes related to lysine metabolism have been implicated in several disease states, including pyridoxine-dependent epilepsia (ALDH7A1 gene), α-ketoadipic and α-aminoadipic aciduria (DHTKD1 gene), and glutaric aciduria type 1 (GCDH gene).
Hyperlysinuria is marked by high amounts of lysine in the urine.
It is often due to a metabolic disease in which a protein involved in the breakdown of lysine is non functional due to a genetic mutation.
It may also occur due to a failure of renal tubular transport.
Use of lysine in animal feed
Lysine production for animal feed is a major global industry, reaching in 2009 almost 700,000 tons for a market value of over €1.22 billion.
Lysine is an important additive to animal feed because it is a limiting amino acid when optimizing the growth of certain animals such as pigs and chickens for the production of meat.
Lysine supplementation allows for the use of lower-cost plant protein (maize, for instance, rather than soy) while maintaining high growth rates, and limiting the pollution from nitrogen excretion.
In turn, however, phosphate pollution is a major environmental cost when corn is used as feed for poultry and swine.
Lysine is industrially produced by microbial fermentation, from a base mainly of sugar.
Genetic engineering research is actively pursuing bacterial strains to improve the efficiency of production and allow lysine to be made from other substrates.
In popular culture
The 1993 film Jurassic Park, which is based on the 1990 novel Jurassic Park by Michael Crichton, features dinosaurs that were genetically altered so that they could not produce lysine, an example of engineered auxotrophy.
This was known as the "lysine contingency" and was supposed to prevent the cloned dinosaurs from surviving outside the park, forcing them to depend on lysine supplements provided by the park's veterinary staff. In reality, no animal can produce lysine, it is an essential amino acid.
In 1996, lysine became the focus of a price-fixing case, the largest in United States history.
The Archer Daniels Midland Company paid a fine of US$100 million, and three of its executives were convicted and served prison time.
Also found guilty in the price-fixing case were two Japanese firms (Ajinomoto, Kyowa Hakko) and a South Korean firm (Sewon).
Secret video recordings of the conspirators fixing lysine's price can be found online or by requesting the video from the U.S. Department of Justice, Antitrust Division.
This case gave the basis for the book The Informant: A True Story, and the movie The Informant!.
Molecular Weight: 146.19 g/mol
XLogP3: -3
Hydrogen Bond Donor Count: 3
Hydrogen Bond Acceptor Count: 4
Rotatable Bond Count: 5
Exact Mass: 146.105527694 g/mol
Monoisotopic Mass: 146.105527694 g/mol
Topological Polar Surface Area: 89.3Ų
Heavy Atom Count: 10
Formal Charge: 0
Complexity: 106
Isotope Atom Count: 0
Defined Atom Stereocenter Count: 0
Undefined Atom Stereocenter Count: 1
Defined Bond Stereocenter Count: 0
Undefined Bond Stereocenter Count: 0
Covalently-Bonded Unit Count: 1
Compound Is Canonicalized: Yes
Lysine is a diamino acid that is caproic (hexanoic) acid bearing two amino substituents at positions 2 and 6.
Lysine has a role as a Daphnia magna metabolite.
Lysine is an alpha-amino acid, a diamino acid and a polar amino acid.
Lysine contains a 4-aminobutyl group.
Lysine is functionally related to a hexanoic acid.
Lysine is a conjugate base of a lysinium(1+).
Lysine is a conjugate acid of a lysinate.
Uses at industrial sites
Lysine has an industrial use resulting in manufacture of another substance (use of intermediates).
Lysine is used for the manufacture of: chemicals.
Release to the environment of this substance can occur from industrial use: as an intermediate step in further manufacturing of another substance (use of intermediates).
Lysine is an essential amino acid.
The human body cannot make lysine, so it must be eaten in the diet. Sources include meat, fish, dairy, and eggs.
Lysine is a building block for making proteins in the body.
Lysine might also prevent the herpes virus from growing.
People use lysine for cold sores, canker sores, athletic performance, diabetes, and many other conditions, but there is no good scientific evidence to support most of these uses.
Cold sores (herpes labialis).
Taking lysine by mouth might help prevent and heal cold sores.
It's not clear if applying it to the skin helps.
There is interest in using lysine for a number of other purposes, but there isn't enough reliable information to say whether it might be helpful.
When taken by mouth: Lysine is possibly safe for most people when taken in doses up to 3000 mg daily for up to one year.
Lysine can cause side effects such as stomach pain and diarrhea.
When applied to the skin: Lysine is possibly safe for most people when used short-term.
Lysine, or L-lysine, is an essential amino acid, meaning it is necessary for human health, but the body cannot make it.
You have to get lysine from food or supplements.
Amino acids like lysine are the building blocks of protein.
Lysine is important for proper growth, and it plays an essential role in the production of carnitine, a nutrient responsible for converting fatty acids into energy and helping lower cholesterol.
Lysine appears to help the body absorb calcium, and it plays an important role in the formation of collagen, a substance important for bones and connective tissues including skin, tendons, and cartilage.
Most people get enough lysine in their diet.
Although athletes, burn patients, and vegans who do not eat beans may need more.
If you do not have enough lysine, you may experience:
Fatigue
Nausea
Dizziness
Loss of appetite
Agitation
Bloodshot eyes
Slow growth
Anemia
Reproductive disorders
For vegans, legumes (beans, peas, and lentils) are the best sources of lysine.
Herpes simplex virus (HSV)
Some studies suggest that taking lysine on a regular basis may help prevent outbreaks of cold sores and genital herpes.
Others show no improvement.
Lysine has antiviral effects by blocking the activity of arginine, which promotes HSV replication. One review found that oral lysine is more effective atpreventing an HSV outbreak than it is at reducing the severity and duration of an outbreak.
One study found that taking lysine at the beginning of a herpes outbreak did not reduce symptoms. Most experts believe that lysine does not improve the healing of cold sores.
But supplementation may reduce recurrences or improve symptoms.
Osteoporosis
Lysine helps the body absorb calcium and reduces the amount of calcium that is lost in urine.
Since calcium is crucial for bone health, some researchers think lysine may help prevent bone loss associated with osteoporosis.
Lab studies suggest that lysine in combination with L-arginine (another amino acid) makes bone-building cells more active and enhances production of collagen.
But no studies have examined whether lysine helps prevent osteoporosis in humans.
Athletic performance
Athletes sometimes use lysine as a protein supplement.
Some studies suggest lysine helps muscle tissue recover after stress.
Dietary Sources
Good sources of lysine include foods that are rich in protein, such as:
Meat, specifically red meat, pork, and poultry
Cheese, particularly parmesan
Certain fish, such as cod and sardines
Eggs
Soybeans, particularly tofu, isolated soy protein, and defatted soybean flour
Spirulina
Fenugreek seed
Brewer's yeast, beans and other legumes, and dairy products also contain lysine.
Available Forms
Lysine is available in tablets, capsules, creams, and liquids, and is usually sold in the L-lysine form.
How to Take Lysine:
Pediatric
Speak with your pediatrician regarding appropriate dosages.
Dosage is usually adjusted based on body weight.
Adult
Dosing depends on different factors.
Talk to your doctor to determine the right dose for you.
Precautions
Because of the potential for side effects and interactions with medications, you should take dietary supplements under the supervision of a knowledgeable health care provider.
Lysine can increase the absorption of calcium. Use caution when taking large amounts of calcium while supplementing with lysine.
While lysine in the diet is considered safe, excessive doses may cause gallstones. There have also been reports of renal dysfunction, including Fanconi syndrome and renal failure.
Talk to your doctor before taking supplemental lysine if you have kidney disease, liver disease, or if you are pregnant or breastfeeding.
Possible Interactions
If you are currently being treated with any of the following medications or supplements, you should not use lysine supplements without first talking to your doctor.
Arginine: Arginine and lysine share common pathways in the body.High levels of arginine may lower lysine levels in the body.
Aminoglycoside antibiotics (gentamicin, neomycin, streptomycin, etc.): Use with lysine may increase the risk of nephrotoxicity.
Lysine, also called L-lysine, is an amino acid that is necessary for many bodily functions.
People describe amino acids as the building blocks of protein because they combine with other compounds to form this macronutrient.
The medical community defines lysine as an essential amino acid because, unlike some other amino acids, the body cannot synthesize it.
As a result, people need to include it in their diet.
Health benefits of Lysine:
The human body needs lysine for healthy functioning.
Lysine is a crucial component of proteins that play a role in helping body tissue grow and recover from damage.
Helping the body absorb calcium, iron, and zinc promoting collagen growth helping produce enzymes, antibodies, and hormones supporting the immune system when people do not get enough lysine, they may experience the following symptoms:
Fatigue
Poor concentration
Irritability
Nausea
Red eyes
Hair loss
Anorexia
Inhibited growth
Anemia
Problems with the reproductive system
Below, we discuss the possible health benefits of lysine supplements.
Treating herpes
Lysine might help control the herpes virus.
As a result, lysine supplements may reduce the number and frequency of cold sore outbreaks, for which the herpes simplex type 1 virus is responsible.
Lysine can also help with the treatment of genital herpes.
Some sources recommend that people with a history of herpes infections take at least 1,000 milligrams (mg) of lysine supplements a day. Smaller amounts than this were found to be ineffective.
One randomized trial of 34 subjects found that taking over 3000 mg a day resulted in far lower rates of recurrence of HSV flareups.
Further research is needed on what the optimal dose may be, and data on this subject remains quite mixed.
A 2015 review failed to find any short-term preventative effects for lysine in the treatment of HSV.
Lowering blood pressure
According to one small-scale study, lysine can help reduce high blood pressure in people whose dietary intake of this amino acid is insufficient.
However, more research is necessary before experts can determine whether or not lysine is an effective treatment for high blood pressure.
Treating diabetes
The results of a small study on 12 healthy volunteers suggest that lysine can slow the rise in blood glucose levels after eating.
This discovery could lead to effective treatments for people with diabetes, but there is still a need for more research.
A small randomized control trial of 110 subjects used a product called Lysulin, a combination of lysine, zinc, amd vitamin C.
Patients in the study experienced improved glycemic control and reduced progression of diabetes. Further research is needed to confirm this effect.
Other benefits of Lysine:
Due to the functions that lysine supports in the body, researchers are interested in the potential of lysine supplements for:
Preventing loss of lean muscle mass and mobility issues in older adults
Relieving anxiety
Preventing bone loss and osteoporosis by helping the body absorb calcium
Promoting the healthy growth of skin
Treating shingles
Moderating blood pressure
Preventing plaque buildup in arteries
Supporting hair growth
Building muscle in bodybuilders
Helping athletes recover from intense workouts
Lysine (abbreviated as Lys or K) is an α-amino acid with the chemical formula HO2CCH(NH2)(CH2)4NH2.
This amino acid is an essential amino acid, which means that humans cannot synthesize it.
Lysine's codons are AAA and AAG.
Lysine is a base, as are arginine and histidine.
The ε-amino group acts as a site for hydrogen binding and a general base in catalysis.
Common posttranslational modifications include methylation of the ε-amino group, giving methyl-, dimethyl-, and trimethyllysine.The latter occurs in calmodulin.
Other posttranslational modifications include acetylation.
Collagen contains hydroxylysine which is derived from lysine by lysyl hydroxylase.
O-Glycosylation of lysine residues in the endoplasmic reticulum or Golgi apparatus is used to mark certain proteins for secretion from the cell.
Lysine is an amino acid. Amino acids are molecules that act as the building blocks of proteins.
Specifically, lysine is an essential amino acid.
That means that your body can’t make lysine on its own, and instead it must be obtained through your diet.
Lysine can be found in protein-rich plant and animal-based foods like eggs, lentils, meat, dairy products, and fish.
Lysine can also be taken as a dietary supplement.
The supplement label might say “l-lysine,” which is the form of lysine used in supplements.
As a supplement, lysine offers a number of benefits.
Benefits of Lysine
Lysine is required for important processes such as:
Growth
Tissue repair
Collagen formation
Calcium absorption
Antibody, hormone, and enzyme production
Most people get plenty of lysine through their diets. Some people—like athletes, those who are being treated for extensive burns, and those following a vegan diet—may not take in enough lysine through their diet alone to meet their needs.
Mount Sinai.
Lysine.
Supplementation of lysine might help make up for that.
Plus, some studies suggest that taking lysine in supplement form may benefit certain medical conditions.
Lysine supplements may benefit people who have recurrent infections caused by the herpes simplex virus (HSV).
To replicate, HSV needs the amino acid arginine.
Lysine blocks HSV from using arginine, which prevents the virus from reproducing.
For this reason, taking high doses of supplemental lysine could help reduce the recurrence of HSV lesions like cold sores and genital sores.5
One review found that when supplemented in doses higher than 3 grams per day, lysine may help reduce the number of herpes flares and self-reported herpes symptoms in people with herpes.
However, more research is needed to understand how lysine supplements affect people with herpes and to determine what minimum daily dose is needed to produce positive effects.
When combined with the amino acid arginine, lysine may help improve anxiety symptoms.
This may be because the body requires amino acids like lysine and arginine for the production of neurotransmitters—chemical messengers that allow nerve cells to communicate. Low amino acid intake could lead to an imbalance in neurotransmitters, which could lead to anxiety.6
An older study of 108 Japanese adults found that those who took a supplement containing 2.6 grams of lysine and 2.6 grams of arginine for one week experienced significant reductions in anxiety.
They also had significant reductions in salivary cortisol, a marker used to assess levels of psychological stress.
Other older studies have had similar outcomes.
Even though these results are encouraging, more studies are needed to investigate the effects of lysine supplementation on anxiety.
Lysine is important to collagen formation.
Collagen may be able to help heal mucosal wounds, which are wounds like sores that affect the moist lining of the inside of your mouth.
Taking lysine supplements can help promote collagen production, in turn, decreasing and preventing sores and inflammation (mucositis) from things like radiation or chemotherapy.
If your diet is low in lysine, taking a lysine supplement may help reduce blood pressure.
In a study conducted in Ghana, people with high blood pressure and suboptimal lysine intake who were supplemented with 500mg of lysine per twice daily for 16 weeks experienced significant reductions in systolic blood pressure compared to a group that took placebo tablets.
Systolic blood pressure is the top number of your blood pressure reading and measures the pressure in your arteries when your heart beats.
High blood pressure can increase your risk of heart disease, heart attack, and stroke.
More research is needed to know the true effect a lysine supplement can have on high blood pressure,
Schizophrenia is a mental health disorder that can cause people to hear voices or see things that aren’t there.
One study showed that when used alongside the schizophrenia medication risperidone, daily supplementation with 6g of lysine (two 1-gram capsules three times a day) for eight weeks led to improvements in schizophrenia symptoms.
More research that uses higher doses and a longer time period are needed.
Some evidence suggests that lysine-rich diets protect against protein breakdown and improve muscle strength.
Twenty under- and well-nourished men who ate a high-lysine diet (80mg per kg of body weight per day) for eight weeks had a slight positive effect on muscle strength.
Therefore, supplementing your diet with lysine may benefit muscle heath.
Good Sources of Lysine
Lysine is concentrated in a number of plant- and animal-based foods, including:
Red meat
Fish
Pork
Poultry
Cheeses, like parmesan
Eggs
Milk
Spirulina
Brewer’s yeast
Lentils
Beans
Peas
Soy products like soybeans and tofu
Fenugreek seed
How to Take Lysine:
Most people get enough lysine through their diet.
However, taking lysine supplements could be helpful for people who don’t eat a lot of lysine-rich foods like meat, fish, eggs, dairy products, and beans or for those who are trying to manage a specific condition.
Lysine supplements are most commonly available as capsules and powders.
You can take lysine on its own or you can take it alongside other amino acids, like arginine.
Most supplement companies suggest taking lysine on an empty stomach for optimal absorption.
However, most studies that have investigated the health effects of lysine supplements didn’t disclose whether participants were instructed to take lysine with meals or on an empty stomach.
Dosage
Most lysine supplements come in tablets that have between 500mg and 1,000mg of lysine per dose.
How much you take and for how long depends on body weight and what condition you’re hoping to help.
Usually, lysine supplements are used in doses up to 3,000mg a day for up to one year.
Lysine has been determined to be likely safe in doses up to 3,000mg a day for up to one year and up to 6,000mg a day for up to eight weeks.
In fact, 6,000mg a day was the highest dose of lysine not associated with adverse side effects like diarrhea and nausea, according to one review that included 71 studies.
Higher doses may be safe, but they may cause side effects like diarrhea and nausea in some people.
Some people may require higher or lower doses of lysine than others, so it’s important to reach out to a healthcare provider if you have questions regarding lysine dosing.
Is Lysine Safe?
Like most amino acids, lysine supplements are considered relatively safe, even at higher doses.14
However, people with medical conditions such as heart disease, kidney disease, liver disease, gallstones, or asthma, as well as those who are pregnant or breastfeeding, should avoid taking lysine supplements unless a healthcare provider prescribes them.
People with lysinuric protein intolerance should also avoid taking lysine supplements.
This intolerance is a rare genetic condition where the body is unable to digest and use certain amino acids such as lysine.
Because people with this condition have a hard time absorbing lysine, taking lysine supplements may cause gastrointestinal side effects such as diarrhea and stomach cramps.
Complications from lysine are rare. There has been one published case report from more than nearly 30 years ago in which experts believed that a lysine supplement caused a woman to develop Fanconi's syndrome, a condition that affects the kidneys and leads to decreased absorption of electrolytes and other important substances. After taking 3000mg of lysine for five years, the woman eventually went into kidney failure.
Potential Drug Interactions
Lysine isn’t known to interact with any medications.
However, if you’re currently taking one or more medications, you shouldn’t start taking lysine supplements without clearing it with your healthcare provider first.
There’s always a chance that a dietary supplement could interact with a medication or another dietary supplement, especially supplements containing more than one ingredient.
Lysine supplements are available for purchase online and in health food stores.
The label might say “l-lysine.”
When shopping for a lysine supplement, it’s important to purchase supplements from trusted brands that adhere to strict quality and safety standards.
Many brands use third-party labs to test their products for quality and purity. Whenever possible, choose supplements that are certified by third-party organizations like UL, USP, and NSF International.
You’ll also want to consider supplement form, cost, and additives.
If you can’t tolerate swallowing pills, a powdered lysine supplement might be a better choice.
When scanning supplement labels, keep an eye out for ingredients that you may prefer to leave out of your diet, like added sugars, fillers, and artificial colors and flavors.
These additives are commonly used in dietary supplements like gummies and powders.
Can You Take Too Much Lysine?
Even though lysine is considered safe at higher doses, you should avoid taking more than 6,000mg per day.
Doses higher than that may cause side effects like stomach cramps, nausea, and diarrhea.
If you’re unsure how much lysine you should be taking per day, ask your healthcare provider for advice.
They can determine whether lysine supplementation is appropriate for your specific needs and can recommend a safe and effective dose.
Side Effects of Lysine:
Lysine isn’t linked with many adverse side effects.
However, taking doses higher than 6,000mg per day may cause digestive symptoms such as:
Diarrhea
Nausea
Stomach cramps
Vomiting
If you experience side effects after taking a lysine supplement, stop taking the supplement and contact your healthcare provider for advice.
Lysine is an essential amino acid that’s involved in growth, tissue repair, collagen production, and other important bodily functions.
Lysine is concentrated in foods like meat, fish, eggs, and beans and can also be taken as a dietary supplement.
While most people get plenty of lysine through their diets and don’t require supplemental lysine, supplementation can be helpful for people who don’t get enough lysine in their diets.
Plus, some evidence suggests that supplemental lysine may be helpful for certain people, like those with recurrent herpes outbreaks or anxiety.
Lysine is an essential amino acid, which means your body needs it to function and repair itself properly.
Amino acids are the building blocks for protein in the body, and lysine is important for proper growth.
Lysine helps the body absorb calcium, and plays an essential role in producing carnitine—a nutrient that converts carbohydrates and fatty acids into energy.iii
But while lysine plays an important role in our everyday health, it’s effectiveness as a cold sore treatment is still a debated topic.
Your body can’t manufacture lysine, so the only way to get it is through your diet.
As one of the building blocks of protein, lysine is found in many protein rich foods such as red meat, fish and dairy products.
If you eat these foods as part of a balanced and healthy diet, your body will get ample amounts of lysine.
Lysine is considered a potential cold sore remedy is because it’s known to slow down the body’s production of arginine another amino acid that helps the HSV virus to spread.
But while some take this to mean that increasing your lysine intake will help to stave off a cold sore outbreak (or treat one that is already occurring), the research on this topic is still inconclusive.
Despite several studies on the topic, experts have not been able to say for sure that lysine can prevent, treat or manage an outbreak of cold sores.
To find out if lysine is right for you, consult your doctor.
Lysine is one of the nine essential amino acids.
Essential because the body cannot synthesize them, so they must be included in a healthy diet.
Lysine is needed to help make protein.
Lysine is also needed to break down carbohydrates and fatty acids.
Lysine may slow or stop the growth of viruses.
Lysine may protect against sexual transmission of the herpes virus.
Lysine may prevent cold sores (herpes sores) from coming back when taken with vitamin C and bioflavonoids.
Lysine may improve how calcium is used.
Lysine may aid in bone growth and healing.
Lysine may also prevent fatigue and increase stress tolerance.
Amino acids (AA) are available as single AAs or in AA combinations.
They also come as part of multivitamins, proteins, and food supplements.
The forms include tablets, fluids, and powders.
By eating enough protein in your diet, you can get all of the amino acids you need.
There are no conditions that increase how much lysine you need.
Lysine is one of the essential amino acids and in cereal based diets it is known to be the most limiting and therefore determines the quality of dietary protein in such diets.
This study investigated the effect of lysine supplementation on blood pressure of hypertensive adults in selected peri-urban community.
Synonyms:
DL-Lysine
70-54-2
2,6-diaminohexanoic acid
Lysine, DL-
(RS)-Lysine
H-DL-Lys-OH
L-Lysine base
UNII-AI4RT59273
CCRIS 8600
(+-)-2,6-Diaminohexanoic acid
AI4RT59273
DL-alpha,epsilon-Diaminocaproic acid
EINECS 200-740-6
(+/-)-LYSINE
CHEBI:25094
DTXSID90859004
EC 200-740-6
L-Lysine-2-15N dihydrochloride
MFCD00064432
(+/-)-2,6-DIAMINOHEXANOIC ACID
Lysine #
(+-)-Lysine
4,4,5,5-tetradeuterolysine
endolysin
MFCD00008234
MFCD00064433
DL-Lysine base
NCGC00164527-01
DL-Lysine, 98%
TETRODOTOXINCITRATE
Lys106
2,6-diamino-hexanoic acid
lysine-4,4,5,5-d4
CHEMBL28328
2,6-bis(azanyl)hexanoic acid
alpha,epsilon-Diaminocaproic acid
DTXCID00196790
CHEBI:132486
(+/-)-2,6-Diaminocaproic acid
HY-B2236
(4,4,5,5-(2)H4)lysine
BBL002414
NSC620353
STK387123
AKOS005441647
CS-7806
NSC-620353
SB23228
NCGC00164527-02
NCGC00166296-01
AS-56068
SY006101
SY006447
SY279831
AM20100662
FT-0625483
FT-0625535
FT-0627942
FT-0693447
FT-0695058
FT-0772133
EN300-34227
A836916
L001250
Q178430
SR-01000944856
Q-201026
SR-01000944856-1
4D4E4503-F6A2-417D-A303-BDCAF08D1EBE
Z57127389
F8880-9052