L-Lysine

Bone Health Wound Healing Immune Support Antiviral Calcium Absorption Collagen Amino Acid Tissue Repair L-Lysine Lysine Cold Sores Herpes Simplex HSV-1 Essential Amino Acid Arginine Balance Protein Synthesis

Published on December 20, 2025 by Guy

L-Lysine is an essential amino acid that must be obtained through diet since the human body cannot synthesize it. Found abundantly in meat, fish, dairy, and eggs, lysine plays fundamental roles in protein synthesis, collagen formation, calcium absorption, and immune function. It is best known for its traditional use in managing herpes simplex virus (cold sores) by helping regulate the lysine-to-arginine balance in the body.

Effects and Benefits

Core Identification

Common Names:
- L-Lysine
- Lysine
- L-Lysine Hydrochloride (supplement form)
- L-Lysine Monohydrochloride

Latin Name: Not applicable (amino acid compound)

Category: Amino Acid

Uses

Traditional Uses

  • Cold sore management - Folk remedy emphasizing high-lysine foods like flounder and dairy to reduce herpes outbreaks
  • Wound healing and tissue repair - Traditional use of protein-rich foods during recovery
  • Building strength during convalescence - Historical use of lysine-rich broths and meats

Modern Uses

  • Cold Sores (Herpes Simplex Type 1) - Reduces frequency, severity, and healing time of outbreaks | Research quality: Moderate
  • Key findings: Field trials involving over 1,500 sufferers found more than 80% reported recurrences were either prevented or decreased in frequency; when sores did occur, severity and healing time were both greatly reduced

  • Source citations: Brewer - Encyclopedia of Vitamins; White - 500 Time-Tested Home Remedies

  • Bone Health and Calcium Absorption - Enhances calcium utilization for bone formation | Research quality: Preliminary

  • Key findings: Lysine, along with Vitamin D, enhances the absorption of calcium, which is critical for healing bone and connective tissue

  • Source citations: Coffman - Herbal Medic

  • Collagen Production - Essential amino acid for connective tissue synthesis | Research quality: Moderate

  • Key findings: Lysine is one of the crucial amino acids required for collagen formation and tissue repair

  • Source citations: Coffman - Herbal Medic; General biochemistry knowledge

  • Immune Support - Aids production of antibodies and enzymes | Research quality: Preliminary

  • Key findings: Lysine supplementation supports immune function and may help the body resist viral infections
  • Source citations: Gladstar - Herbal Recipes for Vibrant Health

Active Compounds

Primary Active Ingredients:
- L-Lysine (free-form amino acid) - The bioactive form used by the body for protein synthesis, enzyme production, and antibody formation
- Competes with arginine for absorption - This competitive relationship is key to its antiviral mechanism against herpes viruses

Dosage Information

Standard Dosage:
- Form: Capsules, tablets, powder
- Amount: 500 mg–1,000 mg per day
- Frequency: Once daily for general maintenance
- Purpose: Prevention and general immune support

Therapeutic Dosage:
- Form: Capsules, tablets, or powder
- Amount: 1,000–3,000 mg per day (in divided doses)
- Purpose: During active cold sore outbreaks
- Duration: Short-term only (a few days to one week maximum)

Maximum Safe Dosage:
- Daily maximum: 3,000 mg (for short-term acute use only)
- Warning threshold: High doses taken long-term may increase cholesterol levels and risk of atherosclerosis

Bioavailability Notes:
- Best absorbed on an empty stomach
- Free-form lysine in supplements is more readily absorbed than lysine from food
- Competes with arginine for intestinal absorption—taking with high-arginine foods may reduce uptake

How to Take It

Timing:
- Take on an empty stomach for optimal absorption
- If stomach upset occurs, may take with a small amount of food (low in arginine)
- For outbreak prevention, consistent daily dosing is more effective than sporadic use

Synergies - What It Works Well With

Complementary Supplements:
1. Vitamin C (with bioflavonoids) - Enhances antiviral effects and speeds cold sore healing | Studies show vitamin C (200 mg with bioflavonoids, 3-5 times daily) reduces healing time significantly when combined with lysine
2. Zinc - Supports immune function and may reduce cold sore duration | Take 15-30 mg daily during active infections
3. Vitamin D - Works with lysine to enhance calcium absorption for bone health | Supports overall immune function
4. Lemon Balm (Melissa officinalis) - Antiviral herb that complements lysine's action against herpes viruses | Both topical and internal use
5. Echinacea - Immune-supportive herb that pairs well during viral outbreaks

Avoidance - What NOT to Combine With

Supplement Interactions:
1. L-Arginine - High arginine intake counteracts lysine's benefits for herpes management | Arginine is required for herpes virus replication; maintain proper lysine-to-arginine ratio

Drug Interactions:
1. Aminoglycoside Antibiotics (e.g., gentamicin, streptomycin) - Theoretical increased risk of kidney issues | Severity level: Mild (precautionary)
2. Calcium Supplements (very high doses) - Lysine increases calcium absorption, which may lead to hypercalcemia in those taking excessive calcium | Severity level: Mild (monitor calcium intake)

Food Interactions:
- High-Arginine Foods (during outbreaks) - Limit or avoid chocolate, nuts (especially peanuts), seeds, oatmeal, wheat germ, and gelatin during active herpes outbreaks, as arginine promotes viral replication

Safety Information

Contraindications:
- Individuals with impaired kidney function (high doses may stress kidneys)
- Those with hypercholesterolemia or cardiovascular disease risk (long-term high doses may elevate cholesterol)
- Not studied extensively in pregnancy—consult healthcare provider

Side Effects:
- Common (at high doses): Nausea, abdominal cramps, diarrhea
- Rare: Gallstones reported at very high long-term intake
- Long-term high-dose use: May increase cholesterol production

Long-Term Use:
- Low doses (500 mg daily) appear safe for extended use
- High doses (2,000+ mg daily) should only be used short-term (days, not weeks or months)
- Monitor cholesterol levels if using regularly
- Cycle recommendations: For prevention, some practitioners suggest taking 5 days on, 2 days off, for extended periods

Special Precautions:
- Surgery: No specific contraindications, but inform surgeon of all supplements
- Pregnancy/Nursing: Insufficient data—consult healthcare provider before use
- Children: Generally safe at food-based levels; supplement use should be guided by a healthcare provider

Primary Uses At-a-Glance

Primary: Cold sores (herpes simplex), immune support, collagen production

Secondary: Bone health, calcium absorption, wound healing, tissue repair

Sources

Local Library:
- Brewer, Sarah - TDT Encyclopedia of Vitamins
- Gladstar, Rosemary - Herbal Recipes for Vibrant Health
- Gladstar, Rosemary - Herbs for Stress & Anxiety
- Coffman, Sam - Herbal Medic
- White, Linda B. - 500 Time-Tested Home Remedies
- Curtis, Susan - Neal's Yard Remedies
- Wilen, Lydia - Healing Remedies
- Lust, John - The Natural Remedy Bible
- Hale, Meredith - Home Remedies
- Balch, Phyllis - Prescription for Herbal Healing

General Knowledge:
- Amino acid biochemistry and protein synthesis
- Clinical trials on lysine for herpes simplex management
- Nutritional research on essential amino acids