Research
L-Lysine
34 peer-reviewed studies curated from PubMed and Semantic Scholar.
Studies
Sorted by quality and recency
Comprehensive Safety Assessment of l-Lysine Supplementation from Clinical Studies: A Systematic Review.
Systematic review assessing the clinical safety of l-lysine supplementation. Included 71 articles with 3357 subjects, examining doses from 16.8 to 17.5 g/d over 1 to 1095 days. Main adverse events were gastrointestinal symptoms, but risk analysis was not statistically significant. No-observed-adverse-effect level identified at 6.0 g/d.
Comparative bioefficacy of lysine from L-lysine hydrochloride or L-lysine sulfate in basal diets containing graded levels of canola meal for female broiler chickens.
A broiler growth assay compared the efficacy of l-lysine HCl and l-lysine sulfate in diets with graded levels of canola meal for female broiler chickens. The study found that l-lysine HCl can be replaced with l-lysine sulfate without adverse effects on broiler performance, and canola meal can be used up to 20% in diets.
Dietary Intervention With a Targeted Micronutrient Formulation Reduces the Visual Discomfort Associated With Vitreous Degeneration.
RCT of 61 patients with symptomatic vitreous floaters comparing a micronutrient formulation to placebo for 6 months. The active group reported significant decreases in visual discomfort and vitreous opacity areas, with improvements in photopic functional contrast sensitivity.
Safety assessment of L-lysine oral intake: a systematic review.
Systematic review evaluating the safety of L-lysine oral intake in humans. The review included 71 studies, with 12 of high quality. The dose range was 16.8-17,500 mg/day over 1-1095 days. Adverse events were mainly gastrointestinal, with a provisional no-observed-adverse-effect level of 6000 mg/person/day. No significant increase in risk for gastrointestinal symptoms was observed.
Protein glycation compromises the bioavailability of milk protein-derived lysine in vivo in healthy adult males: a double-blind, randomized cross-over trial.
Double-blind, randomized cross-over trial in 15 healthy males assessing the impact of milk protein glycation on lysine bioavailability. High glycation levels in milk protein reduced postprandial plasma lysine concentrations and lysine absorption compared to low glycation levels.
Effectiveness and safety of appetite-stimulating syrup in the management of pediatric patients with loss of appetite due to acute or chronic illness: results of a prospective, single-arm, multi-center and open-label study
Prospective, multicenter, single-arm, open-label study evaluating the effectiveness and safety of appetite-stimulating syrup (AST) containing multivitamins, lysine, and zinc in 380 pediatric patients with loss of appetite due to acute or chronic illness. 79.6% of patients reported improved appetite on day 14, with significant increases in food consumption and meal frequency. No severe adverse events were reported.
Dietary Lysine Requirements of Older Adults Stratified by Age and Sex.
This study aimed to define the lysine requirements in healthy older adults using the indicator amino acid oxidation method. It found that the lysine requirement for females aged 60-69 years was 32.9 mg/kg/d and for those over 70 years was 46.2 mg/kg/d. For males, the requirement was 32.2 mg/kg/d. These results provide a basis for assessing the adequacy of diets to meet lysine needs in older adults.
Lysine from Whole Wheat Bread Consumed by Healthy Adult Males Has High Metabolic Availability When Assessed Using the Indicator Amino Acid Oxidation Method.
The study assessed the metabolic availability (MA) of lysine in whole wheat bread using the indicator amino acid oxidation method in five healthy young males. The MA of lysine from whole wheat bread was found to be 90%, although lysine is still limiting in whole wheat bread due to its low concentration.
Bioavailable Lysine Assessed Using the Indicator Amino Acid Oxidation Method in Healthy Young Males is High when Sorghum is Cooked by a Moist Cooking Method.
The study assessed lysine bioavailability in sorghum using the indicator amino acid oxidation method in 5 healthy young men. Lysine bioavailability from sorghum was found to be 94%, and complementation with lentils improved lysine availability in the diet.
The Preventive Effect of L-Lysine on Lysozyme Glycation in Type 2 Diabetes.
The study investigated the effect of L-lysine on lysozyme glycation in type 2 diabetes. In vitro and in vivo experiments showed that L-lysine reduced advanced glycation end products and improved the structure and function of glycated lysozyme, enhancing its bactericidal activity. A clinical trial with 50 patients demonstrated that L-lysine supplementation improved lysozyme activity, suggesting its potential as a therapeutic supplement in T2DM.
Compensatory growth response and carcass quality after a period of lysine restriction in lean meat type barrows.
A 2x2 factorial trial with 192 barrows examined the effects of lysine levels in different feeding periods on performance and carcass quality. The study found that strategic provision of amino acids in specific growth phases can counteract negative effects of amino acid restriction, with sufficient lysine in the late finishing feed being crucial for good carcass quality.
L-lysine as an adjunct to risperidone in patients with chronic schizophrenia: a double-blind, placebo-controlled, randomized trial.
Double-blind, placebo-controlled RCT investigating L-lysine as an adjunct to risperidone in 72 chronic schizophrenia inpatients over 8 weeks. L-lysine improved negative and general psychopathology symptoms on the PANSS scale, with no significant difference in adverse events between groups.
L-lysine dose dependently delays gastric emptying and increases intestinal fluid volume in humans and rats.
The study investigated the dose-dependent effects of L-lysine on gastric emptying and intestinal fluid volume in humans and rats. L-lysine delayed gastric emptying and increased intestinal fluid accumulation in both species, suggesting a role for amino acids in controlling GI motility and secretion.
Investigation of the mechanism(s) involved in decreasing increased fibrinogen activity in hyperglycemic conditions using L-lysine supplementation.
The study investigated the inhibitory effect of L-Lysine on the nonenzymatic glycation of fibrinogen in hyperglycemic conditions, using both in vitro and in vivo methods. L-Lysine improved fibrinogen's structure and function by inhibiting glycation changes in both diabetic patients and in vitro experiments.
Dietary digestible lysine requirements of male and female broilers from forty-nine to sixty-three days of age.
Experiments evaluated digestible lysine requirements in male and female broiler chickens from 49 to 63 days of age. The study determined optimal lysine concentrations for growth performance and breast meat yield, with males requiring 0.87-0.90% and females 0.81% of the diet.
Oral treatment with L-lysine and L-arginine reduces anxiety and basal cortisol levels in healthy humans.
Double-blind, placebo-controlled RCT in 108 healthy Japanese adults testing L-lysine and L-arginine supplementation. The treatment significantly reduced trait and state anxiety and decreased basal levels of salivary cortisol and chromogranin-A in males.
Bioefficacy of L-lysine.H2SO4 relative to L-lysine.HCl in broiler chickens, estimated by slope-ratio model.
A broiler experiment compared the effectiveness of L-lysine.H2SO4 to L-lysine.HCl at various concentrations in the diet. The study found that both forms of lysine were equally efficacious in terms of daily gain, feed conversion efficiency, and nitrogen retention in broiler chickens.
The use of synthetic lysine in the diet of lactating sows.
RCT with 247 lactating sows testing diets with varying levels of L-lysine x HCl replacing lysine from soybean meal. Higher levels of L-lysine x HCl increased preweaning mortality and decreased the number of pigs weaned. Supplementation with methionine, threonine, and tryptophan did not improve outcomes and increased sow weight loss.
The consumption of animal products is associated with plasma levels of alpha-aminoadipic acid (2-AAA).
Cross-sectional study and randomized cross-over dietary intervention trial investigated the association between dietary intake and plasma levels of alpha-aminoadipic acid (2-AAA) in healthy individuals. Self-reported dietary intake of animal products was associated with higher plasma 2-AAA, while lysine supplementation did not significantly increase plasma 2-AAA. A short-term vegetarian diet significantly reduced plasma 2-AAA.
Urinary excretion of amino acids and their advanced glycation end-products (AGEs) in adult kidney transplant recipients with emphasis on lysine: furosine excretion is associated with cardiovascular and all-cause mortality.
Observational study measuring 24-hour urinary excretion of lysine, CML, and furosine in 630 kidney transplant recipients and 41 healthy donors. Lower urinary CML and furosine excretion rates were associated with higher cardiovascular and all-cause mortality in kidney transplant recipients.
Influence of ammonia and lysine supplementation on yeast growth and fermentation with respect to gluten‐free type brewing using unmalted sorghum grain
The study investigated the effects of ammonia (as diammonium phosphate, DAP) and lysine supplementation on yeast growth and fermentation in gluten-free brewing using unmalted sorghum. DAP improved yeast growth and maintained cell numbers better than lysine, which had adverse effects on yeast morphology. Both supplements improved maltose and maltotriose uptake.
l-Lysine Acts as a Serotonin Type 4 Receptor Antagonist to Counteract In Vitro and In Vivo the Stimulatory Effect of Serotonergic Agents on Aldosterone Secretion in Man.
The study investigated l-Lysine's ability to counteract the stimulatory effect of serotonergic agents on aldosterone production. In vitro and in vivo experiments showed that l-Lysine inhibited aldosterone production induced by 5-HT and 5-HT4R agonists. In a double-blind, cross-over, placebo-controlled study with 20 healthy volunteers, l-Lysine significantly reduced the surge of plasma aldosterone induced by metoclopramide, suggesting its potential as a treatment for primary adrenal diseases driven by overexpressed 5-HT receptors.
Intragastric Lysine Lowers the Circulating Glucose and Insulin Responses to a Mixed-Nutrient Drink without Slowing Gastric Emptying in Healthy Adults.
RCT with 12 healthy adults investigating the effects of intragastrically administered lysine on blood glucose and insulin responses to a mixed-nutrient drink. Lysine reduced blood glucose and insulin levels at 60 minutes without affecting gastric emptying or energy intake.
Effect of L-lysine on expression of selected genes, serum concentration of amino acids, muscle growth and performance of growing pigs.
An experiment with 17 pigs was conducted to study the role of dietary L-lysine in protein synthesis control. Pigs on a lysine-adequate diet showed greater weight gain, gain:feed ratio, and muscle growth compared to those on a lysine-deficient diet, suggesting lysine's role in enhancing growth rate and protein synthesis.
Effects of dietary protein and amino acid levels on the expression of selected cationic amino acid transporters and serum amino acid concentration in growing pigs.
The study evaluated the effect of dietary protein and amino acid levels on the expression of cationic amino acid transporters and serum amino acid concentration in 20 growing pigs. The addition of lysine, threonine, and methionine increased the expression of certain transporters and serum lysine concentration, while further addition of leucine affected transporter expression and serum amino acid concentrations.
L-lysine as adjunctive treatment in patients with schizophrenia: a single-blinded, randomized, cross-over pilot study.
Single-blinded, cross-over pilot study of L-lysine as an adjunctive treatment in 10 patients with schizophrenia. L-lysine treatment caused a significant increase in blood concentration and was well tolerated. A significant decrease in positive symptom severity was detected, though effects on PANSS could not be unequivocally assigned to L-lysine. Performance on the Wisconsin Card Sorting Test improved, likely due to training bias.
Subchronic treatment with amino acid mixture of L-lysine and L-arginine modifies neuroendocrine activation during psychosocial stress in subjects with high trait anxiety.
RCT evaluating the effect of L-lysine and L-arginine on neuroendocrine activation during psychosocial stress in 29 healthy subjects with high trait anxiety. The amino acid treatment enhanced hormone levels and galvanic skin responses during stress, but did not affect heart rate and blood pressure. The study suggests potential anxiolytic effects of the amino acid combination.
Effect of oral administration of L-lysine on conjunctivitis caused by feline herpesvirus in cats.
RCT in 8 healthy young adult cats to determine if oral administration of L-lysine lessens the severity of conjunctivitis caused by feline herpesvirus. Cats receiving lysine had less severe conjunctivitis compared to placebo, with higher plasma lysine concentrations.
Lysine-carnitine conversion in normal and undernourished adult men-suggestion of a nonpeptidyl pathway.
The study investigated the conversion of orally administered L-lysine to carnitine in normal and undernourished adult men. In normal adults, lysine administration significantly increased plasma carnitine levels, while undernourished subjects did not show similar changes until after rehabilitation.
Lysine prophylaxis in recurrent herpes simplex labialis: a double-blind, controlled crossover study.
Double-blind, placebo-controlled, crossover study evaluating the prophylactic effect of L-lysine monohydrochloride 1000 mg daily on recurrent herpes simplex labialis in 65 patients. Lysine prophylaxis had no effect on the overall recurrence rate, but more patients were recurrence-free during lysine treatment compared to placebo, suggesting potential benefit for certain individuals.
Bioinspired L‐Lysine‐Doped Polydopamine for Preventing and Treating UV‐Induced Skin Damage
The study constructs a sunscreen hydrogel using L-lysine doped polydopamine to prevent and treat UV-induced skin damage. The hydrogel shows efficient UV shielding, antioxidative, and anti-inflammatory properties, offering protection and repair for sun-exposed skin.
86Y-DOTA0)-D-Phe1-Tyr3-octreotide (SMT487)--a phase 1 clinical study: pharmacokinetics, biodistribution and renal protective effect of different regimens of amino acid co-infusion.
Phase I PET study of 24 patients with neuroendocrine tumours evaluating the pharmacokinetics and dosimetry of (86)Y-SMT487 with amino acid co-infusion. The study found that amino acid infusion, particularly Lys-Arg, significantly reduced renal uptake of (86)Y-SMT487, allowing higher absorbed doses to tumours without reducing tumour uptake.
Treatment of recurrent herpes simplex infections with L-lysine monohydrochloride.
Prospective, randomized, double-blind, placebo-controlled, cross-over study of 41 patients found that 1,248 mg/day of L-Lysine monohydrochloride decreased the recurrence rate of herpes simplex attacks in nonimmunocompromised hosts. A dose of 624 mg/day was not effective. Neither dosage shortened healing time compared to placebo.
Risk Assessment of "Other Substances" – L-lysine
The Norwegian Scientific Committee for Food Safety assessed the risk of L-lysine in food supplements at doses of 1000-3000 mg/day. The report concludes that these doses are unlikely to cause adverse health effects in adults, adolescents, and children aged 10 to <14 years.