Introduction

L-Lysine is an essential amino acid required for protein synthesis, tissue repair, immune function, and the production of collagen and enzymes. Because the body cannot make lysine, it must be obtained through diet or supplementation.

What Is L-Lysine?

L-Lysine is an essential amino acid involved in growth, muscle repair, and immune defense.

• Type: Essential amino acid
• Main role: Protein synthesis and collagen formation
• Storage: Not stored; used as needed

How L-Lysine Works in the Body

L-Lysine participates in multiple biological processes related to tissue integrity and immune health.

• Supports protein synthesis and muscle repair
• Plays a role in collagen and elastin formation
• Enhances calcium absorption and bone health
• Supports immune system function

Sources of L-Lysine

• Meat and poultry
• Fish
• Eggs
• Dairy products
• Legumes (lentils, beans)
• Soy products

L-Lysine Deficiency

L-Lysine deficiency may occur with low protein intake or diets heavily based on refined grains.

Possible deficiency symptoms include:

• Fatigue and weakness
• Poor muscle recovery
• Hair loss
• Anemia
• Increased susceptibility to infections

Dosage & How to Take L-Lysine

• Daily dietary intake: ~1–3 g/day
• Supplemental dose: 500–3000 mg/day
• Higher needs: During illness or intense training

L-Lysine can be taken with or without food.

Forms of L-Lysine

• L-Lysine hydrochloride (HCl)
• Free-form L-Lysine
• Capsules or tablets
• Protein powders

Benefits & Uses

• Supports muscle growth and repair
• Enhances collagen production
• Supports immune defense
• Improves calcium absorption
• May help reduce recurrence of cold sores

Safety, Side Effects & Precautions

• Generally safe at recommended doses
• Excess intake may cause stomach discomfort
• People with kidney disease should consult a doctor
• Maintain balanced amino acid intake

Special Populations

• Athletes: Supports recovery and muscle repair
• Vegetarians: May have lower lysine intake
• Elderly: Supports tissue repair and immunity
• Individuals with frequent infections: May benefit from adequate intake

Frequently Asked Questions

What does L-Lysine do in the body?

L-Lysine supports protein synthesis, collagen formation, immune health, and calcium absorption.

Can L-Lysine be taken daily?

Yes. Daily intake from diet or supplements is safe for healthy individuals.

Is L-Lysine good for immunity?

Yes. It supports immune function and tissue repair.

Can L-Lysine help with cold sores?

L-Lysine may help reduce the frequency and severity of cold sore outbreaks.

Best time to take L-Lysine?

Any time of day; some prefer taking it between meals for better absorption.