Lysine

Lysine is a nutrient belonging to the essential amino acid class.

Lysine is also known as L-lysine, Lisina, Lys and L-lysine hydrochloride.

Lysine is necessary for the body to produce carnitine, which is required for energy production. Lysine helps the body to produce enough collagen, a protein in your skin.

A deficiency in lysine can cause several health problems, such as impaired immunity, skin ailments, and slow growth and development.

The most excellent sources of lysine are animal foods such as meat, chicken, dairy products, eggs, and fish. It is also found in plant-based proteins such as beans, wheat germ, lentils, nuts, soy, and spirulina.

Lysine is absorbed in the small intestine via active transport. It circulates in the bloodstream and helps in protein synthesis and metabolism. Excess lysine is removed primarily through urine after being used for energy and precursor chemicals, which promotes growth and health.

The common side effects of lysine include stomach pain, nausea and diarrhoea.

Lysine supplement is available in tablets, capsules, powders, syrup and ointment. Topical lysine like cream is also available, but only in combination. This means lysine creams contain other substances such as vitamins, minerals, and nutrients.

Biochemical action of lysine

Lysine belonging to the supplement class helps in several metabolic processes. Lysine acts via protein synthesis, collagen formation and metabolism pathway.

Lysine is well known for its involvement in protein synthesis. Lysine participates in the translation process, where it binds, increasing peptide chains, and contributing to the production of functional proteins. Furthermore, lysine plays a vital role in collagen synthesis by generating cross-links that improve the structural integrity of collagen fibres, which is essential for the strength of connective tissues and skin.

Lysine has an impact on metabolism since it is involved in carnitine production. As a precursor, lysine helps in the formation of carnitine, a chemical which helps in the transport of fatty acids into mitochondria for energy production. Lysine is also crucial in epigenetics because it is a substrate for histone changes, particularly methylation and acetylation, which influence chromatin structure and gene expression control.

Furthermore, lysine availability modulates nutrient-sensing pathways like mTOR, which regulates cellular growth and metabolism. Regarding receptors and enzymes, enzymes such as lysyl-tRNA synthetase help lysine integrate into proteins. Lysine receptors, such as the G protein-coupled receptor GPR132, are also involved in various physiological functions. As a result, maintaining a balanced lysine presence within these pathways is critical for proper cellular function, development, and overall health.

Lysine supplement is available in tablets, capsules, powders, syrup and ointment.

• Tablets: To be swallowed whole with water/liquid, as applicable.
• Capsules: To be swallowed whole with water/liquid, as applicable.
• Powders, oral: Powders must be mixed thoroughly with the appropriate amount of liquid and stirred well to dissolve the powder, as applicable.
• Syrup: To be taken by mouth, usually once daily, as applicable.
• Ointment: To be applied as directed by the doctor. It should be used in a small amount to the affected area after cleaning it properly, as applicable.

Lysine can be used as a supplement when the amount of lysine taken from the diet is insufficient.

Lysine supplements may be used to prevent and treat lysine deficiency, a condition in which the body needs lysine.

Adequate oral intake of lysine supplements helps in the biosynthesis of collagen, elastin and carnitine.

Lysine supplements might also prevent the herpes virus from growing.

Vitamins and natural supplements should not replace a balanced diet.

This product is not intended to diagnose, treat or prevent any disease(s).

Lysine may be useful as a supplement for the following health benefits:

• Herpes simplex — prevention and treatment: Oral lysine supplements are most commonly used to prevent and cure herpes simplex labialis outbreaks. Most clinical studies were undertaken in the 1980s, with generally encouraging outcomes for minimizing recurrences when used at large doses over time and possibly reducing severity and enhancing healing time, though this is less consistent.
• Osteoporosis prevention: Lysine supplements may help calcium absorption, which benefits osteoporosis. The predominant role of in vitro and animal studies makes the human impact uncertain. Lysine appears to increase calcium absorption in limited human experiments. However, no recent osteoporosis trials are available. A rat study found that lysine increased calcium absorption, reducing bone loss, although human applicability has yet to be proven. A more robust human study is needed before reaching definitive conclusions.
• Lysinuric protein intolerance: Lysinuric protein intolerance is an autosomal recessive cationic amino acid transport condition that causes reduced intestinal absorption and increased renal loss of lysine, arginine, and ornithine. Long-term low-dose lysine supplementation increases plasma lysine concentrations in patients and can help treat chronic lysine deficiency without inducing side effects like hyperammonaemia.
• Cold Sores: Cold sores are caused by the herpes simplex virus type 1. The type 1 virus can cause a cold sore when the immune system weakens. However, lysine hinders the herpes simplex virus type 1 from multiplying by inhibiting the amino acid arginine, which it requires for replication.
• Diabetes/hyperlipidaemia: Lysine supplements may be beneficial in decreasing blood sugar levels. A tiny study indicated that large dosages of lysine (11 g) administered with glucose resulted in minor blood sugar drops. According to researchers, Lysine supplementation may either help with insulin secretion or help eliminate glucose from the circulation on its own. More research, however, is required.
• Anxiety and mood disturbances: Lysine inhibits the stress response receptors. It is also beneficial to persons who have schizophrenia. Lysine has been studied to see if it can aid anxiety and stress management, but the research is limited. In randomised, double-masked research, cortisol (a stress hormone) was lower in persons who ingested lysine-fortified foods for three months. The study further found that these foods reduced male anxiety levels.

• Wound Healing: Lysine becomes active in the weeks following an injury by boosting collagen formation and hastening the repair process. It also enhances the growth of new blood vessels at the injury site.

Lysine supplementation may be administered orally or topically.

• Orally: Lysine supplements are available as tablets, capsules, powders and syrups that can be taken orally. It is best taken with water on an empty stomach.
• Topically: Open the lid, softly run your fingertips over the surface to pick up the ointment, and then apply it to the targeted area.

The dosage and duration of treatment should be as per the clinical judgment of the treating healthcare professional).

Vitamins and natural supplements should not replace a balanced diet

This product is not intended to diagnose, treat or prevent any disease(s).

• Tablets: 500 mg, 1000 mg
• Capsules: 500 mg, 620 mg
• Powders: 1 lb(454 mg), 3.53 oz (100 g)
• Syrup: 200 mg
• Ointment: 150 mg

Lysine is available in tablets, capsules, powders, syrup and ointment.

Dosage Adjustment for Adult Patients

Herpes simplex infections

Prevention: 1000–3000 mg/day taken long-term (at least 6 months) together with a low-arginine diet.

Acute treatment: minimum 3000 mg/day in divided doses between meals until lesions heal.

Osteoporosis prevention: 400–800 mg l-lysine taken together with calcium supplementation.

Lysine should be used as a supplement that helps in several physiological processes and appropriate dietary restrictions.

• Avoid alcoholic beverages.
• Stay within your daily calorie needs.
• Limit foods and beverages higher in added sugars, saturated fat, and lysine-rich foods,

The dietary restriction should be individualized as per patient requirements.

Recommended Daily Allowance (RDA)

The adult RDA set is 38 mg/kg of body weight per day.

Upper Tolerable Intake (UTL):

The UTL for lysine has been established for dosages of more than 300 mg daily for no longer than 6 months.

Lysine supplementation may be contraindicated in the following conditions:

• Hypersensitivity to lysine
• Chronic kidney disease
• Hepatic impairment
• Interstitial nephritis
• Hyperlysinaemia/hyperlysinuria (An uncommon disorder whereby the body has difficulty adequately digesting lysine and other amino acids)
• Hypercalcemia

For individuals on hemodialysis, lysine from supplements might need to be absorbed better in people.

Lysine supplements should be used cautiously in liver/biliary tract dysfunction.

Lysine supplements should be used with caution in patients with pre-existing kidney issues.

Lysine supplementation may cause diarrhoea and stomach discomfort in children with this rare genetic condition.

In hypercalcaemic conditions, high-dose lysine supplements should be used with caution.

Caution is advised when consuming alcohol with lysine.

Safe to use during breastfeeding within the RDA limits.

Safe to use during pregnancy within the RDA limits.

Limit the consumption of foods and beverages higher in added sugars, saturated fat, and sodium alcoholic beverages, as these substances could hinder lysine absorption.

The adverse reactions related to lysine can be categorized as-

• Common: Gastrointestinal discomfort, nausea and vomiting.
• Less Common: Headache, dizziness, and increased calcium excretion affect bone health.
• Rare: Allergic reactions, such as rash or itching, elevated blood cholesterol levels, kidney impairment

The clinically relevant drug interactions of lysine are briefly summarized here:

• Calcium: Clinical trials have revealed that l-lysine increases intestinal absorption while decreasing renal calcium excretion – a potentially beneficial combination.
• Gastrointestinal agents (5-HT4 agonist): Lysine could decrease the effects of several gastrointestinal medicines known as 5-HT4 agonists.
• Arginine (another amino acid): A high dose of arginine combined with lysine may reduce lysine absorption. This is because some receptors in your body favour arginine over lysine.

The common side of lysine includes the following:

• Stomach pain
• Diarrhoea
• Nausea
• Vomiting

The use of lysine should be prudent in the following group of special populations.

• Pregnancy: Short-term usage of lysine may be safe for many people. Avoid use to be on the safe side.

The RDA of lysine during pregnancy is 51 mg/kg/day.

• Paediatrics: The RDA of lysine is 89 mg/kg/day for infants 7 to 12 months old, 58 mg/kg/day for children 1 to 3 years old, and 40-46 mg/kg/day for children 4 to 18.

Dosage Adjustment for Paediatric Patients

There are no specific dosage adjustments provided.

• Geriatrics: There is no sufficient scientific evidence traceable regarding the use and safety of lysine for use in special populations.
• Lactating mothers: Short-term usage of lysine may be safe for many people. Avoid use to be on the safe side.

The RDA of lysine during breastfeeding is 52 mg/kg/day.

Dosage Adjustment in Kidney Impairment

There are no specific dosage adjustments provided.

Dosage Adjustment in Hepatic Impairment

There are no specific dosage adjustments provided.

The physician should be vigilant about the knowledge pertaining to identifying and treating overdosage of lysine. Overdosage of lysine may lead to hyperlysinemia, which includes symptoms like gastrointestinal discomfort and increased calcium excretion.

There is no specific antidote or treatment for excessive intake of supplemental lysine. When an overdose is suspected, lysine should be terminated immediately. Fluid intake should be increased along with electrolyte monitoring. Supportive therapy should also be given, addressing any symptoms that persist or worsen. Physical treatment might be added if necessary.

Biochemistry profile of lysine

l-Lysine is the biologically active stereoisomer of lysine. Lysine is an essential amino acid needed for protein synthesis and many other metabolic reactions. It helps to maintain muscle mass, promote wound healing, and support the activity of enzymes as a protein-building component. Lysine helps synthesise collagen, which benefits the health of the skin, connective tissues, and bones. Furthermore, lysine serves as a precursor for compounds such as carnitine, essential for energy metabolism, and a substrate for epigenetic alterations. The interaction of lysine with other amino acids influences protein structure and function. While lysine is necessary for growth and health, too much can cause calcium imbalances and gastrointestinal irritation. Maintaining a suitable balance of lysine and other amino acids is critical for optimal metabolic functioning.

Kinetic profile:

• Absorption: Lysine is absorbed in the small intestine. For absorption, it involves active transport mechanisms.
• Distribution: Lysine is transported throughout the body by the bloodstream. It is essential for protein synthesis and other metabolic processes.

• Metabolism: Lysine is transformed in various mechanisms to produce energy and protein.
• Elimination: Excess lysine is mainly removed through the urine. Over-lysine consumption may result in increased excretion.

1. Braun L, Cohen M. October 1, 2014.Herbs and Natural Supplements; 4th Edition Vol-2. Australia. Elsevier.

2. https://www.fssai.gov.in/upload/advisories/2021/07/60f1798019f94Direction_RDA_16_07_2021.pdf

3. . Tessari P. 2019. Nonessential amino acid usage for protein replenishment in humans: a method of estimation; American Society for Nutrition. Department of Medicine, University of Padova, Padova, Italy

4. National Institute of Nutrition. 2011. Dietary guidelines for Indians; 2nd Edition. Hyderabad. India