What is Lysine?

Summary

Optimal Intake (male 85kg/181cm / female 52kg/171cm)

Cognitive optimization male: 2,100-3,000 mg/day with appropriate cofactors
Cognitive optimization female: 1,800-2,500 mg/day with appropriate cofactors
Energy optimization male: 2,100-3,000 mg/day (standard activity), 3,000-3,800 mg/day (athletic performance)
Energy optimization female: 1,800-2,500 mg/day (standard activity), 2,500-3,200 mg/day (athletic performance)
Optimal blood levels: No standard clinical reference range established

Five best animal sources:

Beef steak: 85g (3 oz) provides 2,223 mg (2,100 mg RDA reached with 2.8 oz)
Pork chop: 85g (3 oz) provides 1,954 mg (2,100 mg RDA reached with 3.2 oz)
Chicken breast: 85g (3 oz) provides 2,106 mg (2,100 mg RDA reached with 3 oz)
Turkey breast: 85g (3 oz) provides 1,979 mg (2,100 mg RDA reached with 3.2 oz)
Salmon: 85g (3 oz) provides 1,816 mg (2,100 mg RDA reached with 3.5 oz)

Five best non-animal sources:

Soy protein isolate: 30g (1 oz) provides 1,736 mg (2,100 mg RDA reached with 1.2 oz)
Pumpkin seeds: 28g (1 oz) provides 360 mg (2,100 mg RDA reached with 5.8 oz)
Black beans, cooked: 172g (1 cup) provides 522 mg (2,100 mg RDA reached with 4 cups)
Lentils, cooked: 198g (1 cup) provides 626 mg (2,100 mg RDA reached with 3.4 cups)
Quinoa, cooked: 185g (1 cup) provides 442 mg (2,100 mg RDA reached with 4.8 cups)

Consistent intake required? Yes, lysine is an essential amino acid that cannot be synthesized by the body and must be obtained through diet. It’s not stored in significant amounts, making regular intake necessary for optimal functioning.

Are higher doses dangerous? No established upper limit. Doses up to 3-6 g/day are generally well-tolerated for short periods. Long-term use of very high doses (>10-12 g/day) may cause gastrointestinal discomfort and raise calcium absorption, potentially affecting kidney function.

Optimal timing for intake:

With meals: Consuming with meals containing other amino acids provides a complete protein profile
Pre/post-workout: Taking lysine alongside other essential amino acids can support muscle protein synthesis and recovery
Consistent daily intake: Spreading lysine intake throughout the day ensures steady availability for protein synthesis and other metabolic functions
During stress or illness: Increased intake may be beneficial during periods of stress, infection, or wound healing

Introduction

Lysine (also known as L-lysine) is one of the nine essential amino acids that humans cannot synthesize and must obtain through diet. It is a crucial building block for proteins and serves as a precursor for various biomolecules. Lysine plays several vital roles in the body, including:

Protein synthesis and tissue repair
Collagen formation (crucial for skin, tendons, cartilage)
Enzyme and hormone production
Immune function support
Calcium absorption and conservation
Energy production
Fatty acid metabolism
Neurotransmitter synthesis

Lysine is unique among amino acids for its strong positive charge, which allows it to form ionic bonds with negatively charged molecules. This property is essential for protein structure and function. It also has a straightforward side chain that cannot be synthesized by human metabolic pathways, making dietary intake essential.

According to Dr. Paul Saladino and other proponents of animal-based diets, lysine is substantially more bioavailable from animal sources compared to plant sources. Experts like Dr. Rhonda Patrick highlight lysine’s role in collagen formation and immune function, while Dr. Andrew Huberman discusses its potential benefits for neurotransmitter balance and stress response.

Effects at Different Lysine Levels

Optimal Levels

Efficient protein synthesis
Normal collagen production and tissue repair
Proper immune system function
Healthy calcium absorption and utilization
Normal hormone and enzyme production
Optimal herpes virus suppression
Proper fatty acid metabolism
Normal energy production
Balanced neurotransmitter function
Efficient stress response
Optimal muscle protein synthesis and repair
Normal carnitine production
Healthy hormone regulation

Deficiency

Reduced protein synthesis
Fatigue and weakness
Impaired immune function
Slower wound healing
Bloodshot eyes
Hair loss
Poor concentration
Irritability
Anemia
Reproductive disorders
Reduced appetite
Growth impairment (in children)
Recurrent herpes virus outbreaks
Reduced exercise recovery

Severe Deficiency

Significant muscle loss
Severe fatigue
Impaired immune response
Failure to thrive in children
Hormone production issues
Reproductive problems
Severe anemia
Compromised wound healing
Growth stunting
Serious metabolic disruptions
Increased viral susceptibility
Mood disorders
Cognitive impairment
Brittle hair and nails

Excess (Hyperlysemia)

Generally well-tolerated in healthy individuals
Possible gastrointestinal discomfort at very high intakes
Potential increase in calcium absorption (concern for renal patients)
Possible interaction with certain medications
Generally considered safe even at several times the RDA

Recommended Dosage

Lysine intake is measured in milligrams (mg) or grams (g).

General Recommendations

By Age Group

Age Group	RDA (mg/day)
Infants (0-6 months)	85*
Infants (7-12 months)	120*
Children (1-3 years)	350
Children (4-8 years)	500
Children (9-13 years)	700
Males (14-18 years)	1,000
Females (14-18 years)	900
Males (19+ years)	1,000-2,100**
Females (19+ years)	900-1,800**
Pregnancy	1,100-2,100**
Lactation	1,300-2,100**

*Adequate Intake (AI) rather than RDA **Higher end values based on the WHO’s recommendation of approximately 30 mg/kg body weight

For Specific Body Types

Male (85kg, 181cm)

Standard RDA: 1,000 mg/day
WHO recommendation based on weight: ~2,100 mg/day (30 mg/kg)
Adjusted for athletic activity: 2,500-3,800 mg/day
For optimal cognitive performance: 2,100-3,000 mg/day with appropriate cofactors

Female (52kg, 171cm)

Standard RDA: 900 mg/day
WHO recommendation based on weight: ~1,800 mg/day (30 mg/kg)
Adjusted for athletic activity: 2,000-3,200 mg/day
For optimal cognitive performance: 1,800-2,500 mg/day with appropriate cofactors

The RDA represents the minimum amount needed to prevent deficiency in a healthy individual. Many experts suggest higher intakes for optimal performance, especially for athletes, those recovering from injury, or individuals under significant stress. Dr. Paul Saladino and other functional medicine practitioners often recommend intakes closer to the WHO’s higher recommendations, especially for those consuming lower protein diets.

Safe Upper Limits & Toxicity

Maximum Safe Dosage

Upper Intake Levels

There is no established Upper Limit (UL) for lysine intake from either food or supplements. Clinical trials have used doses of 3-6 g/day without significant adverse effects in most healthy individuals.

For Specific Body Types

Male (85kg, 181cm)

No established Upper Limit
Doses of 3-6 g/day generally well-tolerated in healthy individuals
Short-term therapeutic doses up to 9 g/day have been used in clinical settings

Female (52kg, 171cm)

No established Upper Limit
Doses of 3-5 g/day generally well-tolerated in healthy individuals
Short-term therapeutic doses up to 6-8 g/day have been used in clinical settings

Note: While there is no official upper limit, very high doses (above 10-12 g/day) may cause gastrointestinal discomfort and potentially affect kidney function due to increased calcium absorption. Individuals with kidney issues or those taking certain medications should consult healthcare providers before using high-dose supplements.

Dangerous Dose Levels

Acute Toxicity: Not established; lysine has very low toxicity
Chronic Toxicity: No specific level established; potential concerns with very high doses (>15 g/day) over long periods
Blood Levels: No standard clinical range for toxicity established

Signs of Lysine Excess

Due to lysine’s relatively low toxicity, signs of excess are rare but may include:

Gastrointestinal discomfort
Abdominal cramps
Diarrhea
Increased calcium absorption (concern for individuals with kidney issues)
Potential gallstone formation with very long-term, high-dose use
Possible interaction with certain medications

Health Effects and Benefits

Protein Synthesis and Muscle Health

Essential building block for all body proteins
Critical for muscle protein synthesis and repair
Supports maintenance of lean muscle mass
Aids in post-exercise recovery
Helps prevent muscle breakdown during stress or fasting
Supports structural proteins throughout the body
Critical component of muscle contractile proteins
Enhances exercise recovery timeframes

Collagen Formation

Key component of collagen structure
Essential for skin elasticity and wound healing
Supports connective tissue integrity
Beneficial for joint and tendon health
Aids in maintaining bone matrix structure
Potentially beneficial for skin appearance
Supports blood vessel integrity
Aids post-injury tissue repair

Immune Function

Supports production of antibodies and immune cells
May help manage herpes virus outbreaks (cold sores, herpes zoster)
Enhances response to certain infections
Supports immune cell proliferation
Aids in maintaining mucosal barriers
Helps regulate inflammation processes
Supports recovery from illness
May reduce frequency and severity of certain viral infections

Calcium Regulation

Enhances calcium absorption
Reduces calcium excretion
Supports healthy bone density
May help prevent osteoporosis
Assists in maintaining proper calcium balance
Supports dental health
Works synergistically with vitamin D
Contributes to proper nerve and muscle function

Energy Production

Component of carnitine (essential for fatty acid transport)
Supports mitochondrial function
Aids in energy metabolism
Helps convert fatty acids to usable energy
Supports glucose utilization
Aids in stress recovery
Helps maintain energy levels during physical exertion
Supports metabolic efficiency

Brain Health and Neurotransmission

Precursor to certain neurotransmitters
Supports healthy stress response
May aid in anxiety reduction
Supports cognitive function
Aids in maintaining blood-brain barrier integrity
May help regulate serotonin through tryptophan competition
Supports normal sleep-wake cycles
Potential mood-stabilizing effects

Deficiency Symptoms

Lysine deficiency can cause:

Fatigue and weakness
Slow wound healing
Anemia
Hair loss
Bloodshot eyes
Poor concentration
Irritability
Nausea, vomiting, or dizziness
Reduced appetite and weight loss
Reproductive disorders
Impaired immune function
Increased frequency/severity of herpes virus outbreaks
Poor recovery from exercise
Growth retardation in children
Impaired collagen synthesis
Connective tissue disorders
Muscle protein breakdown
Hormonal imbalances
Mood disturbances
Immunologic impairment

Sources of Lysine

Food Sources with Amounts to Meet Requirements

Animal Sources

Food	Serving Size	Lysine Content (mg)	Amount to Reach RDA (2,100 mg)	Amount to Reach UL (N/A)
Beef steak	85g (3 oz)	2,223	80g (2.8 oz)	N/A
Pork chop	85g (3 oz)	1,954	91g (3.2 oz)	N/A
Chicken breast	85g (3 oz)	2,106	85g (3 oz)	N/A
Turkey breast	85g (3 oz)	1,979	90g (3.2 oz)	N/A
Salmon	85g (3 oz)	1,816	98g (3.5 oz)	N/A
Tuna	85g (3 oz)	1,900	94g (3.3 oz)	N/A
Eggs	2 large (100g)	880	477g (9.5 eggs)	N/A
Cheese, parmesan	28g (1 oz)	580	102g (3.6 oz)	N/A
Greek yogurt	170g (6 oz)	636	560g (19.8 oz)	N/A

Plant Sources

Food	Serving Size	Lysine Content (mg)	Amount to Reach RDA (2,100 mg)	Amount to Reach UL (N/A)
Soy protein isolate	30g (1 oz)	1,736	36g (1.2 oz)	N/A
Pumpkin seeds	28g (1 oz)	360	164g (5.8 oz)	N/A
Black beans, cooked	172g (1 cup)	522	688g (4 cups)	N/A
Lentils, cooked	198g (1 cup)	626	665g (3.4 cups)	N/A
Quinoa, cooked	185g (1 cup)	442	880g (4.8 cups)	N/A
Tofu, firm	126g (½ cup)	582	455g (1.8 cups)	N/A
Spirulina	7g (1 tbsp)	250	59g (8.4 tbsp)	N/A
Chickpeas, cooked	164g (1 cup)	486	709g (4.3 cups)	N/A
Amaranth, cooked	246g (1 cup)	515	1,005g (4.1 cups)	N/A
Pistachios	28g (1 oz)	333	177g (6.3 oz)	N/A

*Note: Lysine content can vary based on growing conditions, preparation methods, and specific varieties. These values are averages. There is no established UL (Upper Limit) for lysine from food sources or supplements.

Supplements

Types of Lysine Supplements

L-Lysine HCl: The most common form, highly absorbable, typically containing 80% lysine by weight
L-Lysine Base: Pure form of lysine, less common than the HCl form
L-Lysine Orotate: Less common form, sometimes promoted for better absorption
L-Lysine + Zinc: Combination supplements targeting immune function
L-Lysine + Bioflavonoids: Formulated specifically for herpes management
L-Lysine in Multi-Amino Acids: Found in EAA (Essential Amino Acid) complexes
Lysine + Arginine Combinations: Balanced for specific applications like growth hormone support
Time-Release Formulations: Designed to provide sustained release

Considerations When Choosing Supplements

Purity: Choose pharmaceutical grade supplements with third-party testing
Form: HCl form is most common and well-researched
Dosage: Choose appropriate dosage based on your needs (500mg, 1000mg, etc.)
Timing: Consider digestibility and interaction with meals
Additional Ingredients: Some formulations include cofactors like B6, zinc, or vitamin C
Stomach Sensitivity: Take with meals if you experience discomfort
Cost Effectiveness: Compare cost per gram of active lysine
Dietary Restrictions: Check for allergens and whether the product is suitable for vegans

Dr. Saladino and other functional medicine practitioners generally recommend getting lysine from whole food sources when possible, particularly animal products due to their complete amino acid profiles and higher bioavailability. Supplements are typically recommended primarily for therapeutic uses or for those with restricted diets.

Lysine Optimization Strategies

Absorption Enhancement

Consume with Vitamin C: Improves absorption and utilization
Balanced Intake with Other Amino Acids: Proper ratios enhance overall protein utilization
Avoid Excessive Sugar: High sugar consumption may compete with lysine for absorption
Zinc Adequacy: Ensuring sufficient zinc supports lysine metabolism
Healthy Digestive Function: Optimal stomach acid and digestive enzyme production improves absorption
Properly Timed Intake: Taking on an empty stomach may improve absorption as a supplement
Avoid Excessive Arginine: Very high arginine intake can compete with lysine absorption

Dietary Strategies

Animal Protein Focus: Include lysine-rich animal proteins daily for optimal bioavailability
Strategic Plant Combining: For plant-based diets, combine cereals (low lysine) with legumes (higher lysine)
Meal Frequency: Spread protein intake throughout the day for optimal utilization
Diverse Protein Sources: Rotate between different high-lysine foods for nutrient synergy
Minimal Processing: Whole food sources preserve lysine content better than heavily processed foods
Proper Cooking Methods: Avoid excessive high-heat cooking which can damage lysine
Fermentation: Fermented foods may have enhanced lysine bioavailability

Supplement Strategies for Optimal Energy

Timing Strategy: Take 500-1000mg with breakfast and lunch rather than a single large dose
Exercise Support: 1-1.5g 30-60 minutes before or after workouts may improve recovery
Stress Protocol: Increase intake during periods of high stress when demand increases
Cofactor Integration: Combine with B-complex vitamins and magnesium for enhanced energy production
Carnitine Connection: Pair with carnitine or its precursors for optimized energy metabolism
Cycling Approach: Some practitioners recommend periodic increases in dosage followed by maintenance periods
Morning Emphasis: Higher morning doses may support daily energy levels

Synergistic Nutrients

Vitamin B6: Critical for lysine metabolism and utilization
Vitamin C: Enhances collagen formation and lysine utilization
Zinc: Works with lysine for tissue repair and immune function
Bioflavonoids: May enhance the effects of lysine on herpes suppression
Iron: Works synergistically for optimal hemoglobin formation
Vitamin D: Enhances lysine’s role in calcium regulation
Vitamin A: Supports lysine’s immune-enhancing effects
Magnesium: Supports energy production pathways involving lysine
B-Complex Vitamins: Work with lysine in various metabolic pathways

Special Considerations

Pregnancy and Breastfeeding

Lysine needs increase during pregnancy and lactation
Adequate lysine supports fetal growth and development
Important for maternal tissue repair after delivery
Supports milk protein production during lactation
RDA increases to 1,100-2,100 mg/day during pregnancy
RDA increases to 1,300-2,100 mg/day during lactation
Food sources preferred over supplements during pregnancy
Consultation with healthcare provider recommended before supplementation

Medical Conditions Affecting Lysine

Herpes Simplex Virus: May benefit from higher lysine intake
Osteoporosis: Lysine’s role in calcium absorption may be beneficial
Wound healing issues: May require increased lysine for tissue repair
Kidney disease: May affect lysine metabolism and requirements
Malabsorption disorders: May impair lysine absorption
Burns and major trauma: Significantly increased lysine needs
Athletic overtraining: May increase lysine requirements

Medication Interactions

Calcium supplements: Lysine may increase calcium absorption
Aminoglycoside antibiotics: Potential for increased nephrotoxicity with very high lysine doses
Arginine supplements: Competitive inhibition possible
Immunosuppressants: Potential interaction with lysine’s immune effects
Growth hormones: Lysine may potentiate effects
Antiviral medications: Possible synergistic effects with lysine

Personalized Recommendations

For Male (85kg, 181cm)

Aim for at least 2,100 mg/day (WHO recommendation); athletic individuals may benefit from 2,500-3,800 mg/day
Include 100-150g of animal protein daily to easily meet lysine requirements
Consider 1,000-1,500 mg of supplemental lysine during periods of stress, intense training, or at first sign of herpes outbreak
Prioritize lysine-rich foods like beef, chicken, fish, and pork
For optimal cognitive benefits, ensure adequate B6, zinc, and magnesium intake alongside lysine
Test amino acid levels annually if engaged in intense physical training
Increase intake during periods of injury recovery or significant stress
Maintain adequate hydration to optimize amino acid utilization
Spread protein intake throughout the day for optimal muscle protein synthesis

For Female (52kg, 171cm)

Target at least 1,800 mg/day (WHO recommendation); active women may benefit from 2,000-3,200 mg/day
Include 80-120g of animal protein daily to meet lysine requirements
Consider 750-1,000 mg of supplemental lysine during periods of stress, intense exercise, or herpes outbreak
Prioritize lysine-rich foods like poultry, fish, eggs, and dairy
For skin and connective tissue health, combine lysine with vitamin C and zinc
Pay attention to lysine intake during menstruation when protein needs may increase
During pregnancy and lactation, prioritize lysine-rich foods and consult a healthcare provider about supplementation
Increase intake during recovery from injury or surgery
For optimal energy, combine lysine with B-vitamins and iron-rich foods

Activity-Level Adjustments

Sedentary: Standard WHO recommendation is usually sufficient
Moderately Active: Increase by 10-15% (additional 200-300 mg/day)
Athletic/Intense Training: Increase by 20-30% (additional 400-600 mg/day)
Endurance Athletes: May require increases of 30-50% (additional 600-1,000 mg/day)
Recovery Phases: Temporarily increase intake by 20-30% during injury recovery
Stress Periods: Consider temporary increases of 15-25% during high stress

Lysine for Cognitive Performance

Current Research Highlights

Plays a role in the transport of fatty acids to the brain for energy
Supports neurotransmitter production
May help regulate serotonin availability through competition with tryptophan
Supports stress response regulation
May help reduce anxiety by modulating serotonin and other neurotransmitters
Supports sleep quality through melatonin pathway interactions
Helps maintain blood-brain barrier integrity
Supports brain tissue repair and maintenance
May help regulate excitatory neurotransmission

Implementation Strategies

Combine lysine supplementation with B6 for enhanced neurotransmitter synthesis
Morning doses (1,000-1,500 mg) may support daytime cognitive performance
Consider lysine and arginine balance for optimal cognitive effects
Pair with omega-3 fatty acids for synergistic effects on brain function
Include adequate zinc and magnesium as cofactors
During high stress periods, increase intake to support cognitive resilience
Monitor subjective improvements in focus, stress tolerance, and mental clarity
Consider post-workout lysine to support recovery and cognitive performance

Lysine for Energy Production

Metabolic Mechanisms

Essential component in carnitine synthesis (required for fatty acid transport into mitochondria)
Supports ATP production and utilization
Involved in glucose metabolism
Helps maintain muscle energy storage (creatine synthesis pathway)
Supports mitochondrial function
Aids hormonal balance related to energy regulation
Helps maintain blood glucose stability
Supports recovery from energy-demanding activities

Implementation Strategies

Prioritize lysine intake with morning and mid-day meals for sustained energy
Combine with B-complex vitamins for enhanced energy metabolism
Consider 500-1,000mg pre-workout for improved energy availability
Pair with magnesium for optimal energy production pathways
Ensure adequate iron intake for optimal energy transfer systems
For energy resilience, maintain consistent daily lysine intake
During energy slumps, consider additional 500-1,000mg with low-sugar snack
Monitor subjective and objective improvements in stamina and recovery

Expert Insights

Dr. Huberman suggests that amino acid balance affects neurotransmitter production, impacting energy perception
Dr. Rhonda Patrick discusses lysine’s importance in mitochondrial function and energy metabolism
Dr. Paul Saladino emphasizes the superior bioavailability of lysine from animal sources for optimal energy
Dr. Shawn Baker highlights lysine’s role in muscle repair and recovery on a carnivore diet
Research suggests that lysine’s contribution to carnitine synthesis is especially important for fatty acid utilization in a low-carb or keto diet

Summary

Lysine is an essential amino acid critical for protein synthesis, collagen formation, energy production, calcium regulation, and immune function. Its importance extends to cognitive function, stress response, and metabolic health.

Getting Enough: Most people consuming adequate animal protein easily meet lysine requirements; plant-based diets require strategic combinations
Avoiding Excess: No established upper limit, but very high doses unnecessary for most people
Best Approach: Focus on whole food sources, especially animal proteins, with supplementation reserved for specific therapeutic needs
Form Matters: L-lysine HCl is the most common and well-researched supplement form
Energy Optimization: Emphasize consistent intake throughout the day, ensure adequate B-vitamin and mineral cofactors
Cognitive Enhancement: Consider lysine’s interaction with other amino acids and neurotransmitter pathways
Synergistic Approach: Combine with appropriate cofactors like vitamins B6, C, zinc, and magnesium

Remember that individual nutritional needs vary based on activity level, stress, dietary pattern, health conditions, and genetic factors. Consult with a healthcare provider before starting high-dose supplementation or if you have underlying health concerns.