While some complementary and alternative techniques have been studied scientifically, high-quality data regarding safety, effectiveness, and mechanism of action are limited or controversial for most therapies. Whenever possible, it is recommended that practitioners be licensed by a recognized professional organization that adheres to clearly published standards. In addition, before starting a new technique or engaging a practitioner, it is recommended that patients speak with their primary healthcare provider(s). Potential benefits, risks (including financial costs), and alternatives should be carefully considered. The below monograph is designed to provide historical background and an overview of clinically-oriented research, and neither advocates for or against the use of a particular therapy.
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.
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.
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)
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.
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
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)
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.
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.
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
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)
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.
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.
*Key to grades:
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious and should be evaluated by a qualified health care professional.
- Adrenal insufficiency / Addison’s disease (lowered adrenal gland function), antibacterial, Bell’s palsy (one-sided facial paralysis), blood clots, bone loss, cancer, cataracts (cloudy eyes), chronic fatigue syndrome, clogged arteries, colon inflammation, dental hygiene, dental surgery adjunct, food additive, hair loss, high cholesterol, HIV/AIDS, immune suppression, liver inflammation, menstrual pain, metabolic disorders (cystinuria, excess cysteine in the urine), migraine, osteoporosis, respiratory tract infections, sepsis (severe bacterial infection).
The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
Adults (18 years and older)
According to the U.S. Department of Agriculture (USDA), the recommended dietary allowance (RDA) of lysine in adults over 19 years old is 38 milligrams per kilogram of body weight daily. During pregnancy and breastfeeding, the RDA is increased to 51 and 52 milligrams per kilogram daily, respectively.
For the prevention and treatment of canker sores, 500 milligrams and 1,000 milligrams of lysine, respectively, has been taken by mouth daily for an indefinite amount of time.
For herpes infections, 1,000-3,000 milligrams of lysine has been taken daily for 12 weeks to 12 months by mouth, as either a single or divided dose. For recurring symptoms, an initial 1,000 milligrams once daily has also been taken by mouth, followed by 500 milligrams twice daily until 11 capsules have been used.
For gyrate atrophy (an eye disorder due to excess ornithine), six grams of lysine has been taken by mouth once daily for one day, followed by two grams of lysine five times daily for seven days.
For stress, wheat flour fortified with lysine at a ratio of 4.2 grams of lysine per kilogram of wheat flour has been taken by mouth for three months.
Children (under 18 years old)
According to the U.S. Department of Agriculture (USDA), the recommended dietary allowance (RDA) of lysine is 89 milligrams per kilogram of body weight daily for children 7-12 months old, 58 milligrams per kilogram daily for children 1-3 years old, and 40-46 milligrams per kilogram daily for children 4-18 years old.
To promote childhood growth, 0.66 grams of lysine has been divided and taken by mouth three times daily (0.22 grams each) for six months.
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
Avoid in people with a known allergy or sensitivity to lysine.
Side Effects and Warnings
In healthy adults, up to 3,000 milligrams of lysine is likely safe when taken by mouth once daily for six months. Caution is advised for use longer than six months, due to a lack of available safety information.
Lysine may cause abnormal albumin excretion, altered immune function, altered protein metabolism, ammonia intoxication, cramping, diarrhea, gallstones, kidney malfunction (including Fanconi’s syndrome, kidney tubule damage, and chronic renal failure), impaired liver function, increased cholesterol, pancreas damage, and stomach upset.
Lysine may increase the risk of bleeding. Caution is advised in people with bleeding disorders or those taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary.
Lysine may lower blood sugar levels and cause abnormal albumin excretion. Caution is advised in people with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Blood glucose levels may need to be monitored by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
Use cautiously in people with disorders of altered amino acid metabolism, increased likelihood of gallstones, lowered immune system function, thymus disorders, high blood lipids, or lowered pancreas function, or in those using agents that stimulate 5-HT4 receptors or when combined with protein-bound or protein-based medications.
Avoid in people with kidney and liver problems.
Unless lysine deficient, avoid use in pregnant or breastfeeding women, due to a lack of safety information.
Avoid with known allergy or sensitivity to lysine.
Pregnancy and Breastfeeding
Unless for the improvement of lysine deficiency, avoid use in pregnant or breastfeeding women, due to a lack of safety information.
Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.
Interactions with Drugs
Lysine may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants (blood thinners) such as warfarin (Coumadin®) or heparin, antiplatelet drugs such as clopidogrel (Plavix®), and nonsteroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).
Lysine may lower blood sugar levels. Caution is advised when using medications that may also lower blood sugar. People taking insulin or drugs for diabetes by mouth should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
Lysine may also interact with agents that affect the immune system, agents that simulate 5-HT4 receptors, amphetamines (agents that simulate the central nervous system), antibiotics, antivirals, aprotinin, kidney-damaging agents, and lipid-lowering agents.
Interactions with Herbs and Dietary Supplements
Lysine may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.
Lysine may lower blood sugar levels. Caution is advised when using herbs or supplements that may also lower blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.
Lysine may also interact with amino acids, antibacterials, antivirals, arginine, calcium, carnitine, herbs and supplements that affect the immune system, iron, kidney-damaging herbs and supplements, lipid-lowering herbs and supplements, protein, and zinc.
This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).
Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.
- Kurpad AV, Young VR. What is apparent is not always real: lessons from lysine requirement studies in adult humans. J Nutr 2003;133(4):1227-1230. View Abstract
- Lukkarinen M, Nanto-Salonen K, Pulkki, K, et al.. Oral supplementation corrects plasma lysine concentrations in lysinuric protein intolerance. Metabolism 2003;52(7):935-938. View Abstract
- Miller CS, Foulke CN. Use of lysine in treating recurrent oral herpes simplex infections. Gen Dent 1984;32(6):490-493. View Abstract
- Milman N, Scheibel J, Jessen O. Failure of lysine treatment in recurrent herpes simplex labialis. Lancet 1978;2(8096):942. View Abstract
- Natarajan Sulochana K, Lakshmi S, Punitham R, et al. Effect of oral supplementation of free amino acids in type 2 diabetic patients– a pilot clinical trial. Med Sci Monit 2002;8(3):CR131-CR137. View Abstract
- Perfect MM, Bourne N, Ebel C, et al. Use of complementary and alternative medicine for the treatment of genital herpes. Herpes 2005;12(2):38-41. View Abstract
- Peltola K, Heinonen OJ, Nanto-Salonen K, et al. Oral lysine feeding in gyrate atrophy with hyperornithinaemia–a pilot study. J Inherit Metab Dis 2000;23(4):305-307. View Abstract
- Pereira SM, Begum A, Jesudian G, et al. Lysine-supplemented wheat and growth of preschool children. Am J Clin Nutr 1969;22(5):606-611. View Abstract
- Smriga M, Ghosh S, Mouneimne Y, et al. Lysine fortification reduces anxiety and lessens stress in family members in economically weak communities in northwest Syria. Proc Natl Acad Sci U S A 2004;101(22):8285-8288. View Abstract
- Smriga M, Torii K. Metabolic interactions between restraint stress and L-lysine: the effect on urea cycle components. Amino Acids 2003;24(4):435-437. View Abstract
- Sulochana KN, Rajesh M, Ramakrishnan S. Insulin receptor tyrosine kinase activity in monocytes of type 2 diabetes mellitus patients receiving oral L-lysine. Indian J Biochem.Biophys 2001;38(5):331-334. View Abstract
- Tomblin FA Jr, Lucas, KH. Lysine for management of herpes labialis. Am J Health Syst Pharm 2001;58(4):298-300,304. View Abstract
- Williams MH. Facts and fallacies of purported ergogenic amino acid supplements. Clin Sports Med 1999;18(3):633-649. View Abstract
- Wright EF. Clinical effectiveness of lysine in treating recurrent aphthous ulcers and herpes labialis. Gen Dent 1994;42(1):40-42. View Abstract
- [The effect of L-lysine added to diet on growth and development of normal children (author’s transl)]. Zhonghua Yi Xue Za Zhi 1982;62(1):11-12. View Abstract
Copyright © 2013 Natural Standard (www.naturalstandard.com)
The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.