L-Lysine - Available in Powder & Capsules, Now Foods

Now Foods 100% Pure L-Lysine Powder is a pharmaceutical-grade, free-form essential amino acid in a generous 454g bulk format — the same trusted lysine used for immune support, collagen synthesis, cold sore and herpes simplex management, and general tissue health, at outstanding value per serve. Approximately 378 servings at ¼ tsp daily. Pure powder, no additives.

Why you need it

L-lysine is one of nine essential amino acids — meaning the body cannot synthesise it and must obtain it entirely from diet or supplementation. It plays several distinct and important roles in human health.

Cold sore & herpes simplex management: Lysine is best known for its role in managing herpes simplex virus (HSV) outbreaks, including cold sores and shingles. The virus requires arginine to replicate — and lysine competes directly with arginine for absorption and cellular uptake, reducing the arginine available to the virus. Research consistently shows that lysine supplementation reduces the frequency, severity, and duration of outbreaks in those prone to them.

Collagen synthesis: Lysine is a critical building block for collagen — required for the hydroxylation of proline and the cross-linking of collagen fibres that give connective tissue its strength. Without adequate lysine, collagen production is impaired, affecting skin, tendons, ligaments, cartilage, and bone.

Immune function & serotonin regulation: Lysine supports antibody production and immune cell function, and research suggests it plays a role in regulating serotonin receptors in the brain, which may contribute to its stress-supportive effects. It also enhances calcium absorption from the gut and reduces urinary calcium loss, supporting bone density over time.

Key benefits

• Cold sore & HSV management — competes with arginine to reduce herpes simplex replication
• Collagen synthesis — essential for cross-linking collagen in skin, tendons, ligaments, and bone
• Immune support — supports antibody production and immune cell function
• Serotonin regulation — may support mood and stress resilience via serotonin receptor modulation
• Calcium absorption — enhances uptake and reduces urinary calcium loss
• Bulk value — 454g providing ~378 servings at outstanding cost per dose

Formula

100% pure L-lysine powder. No fillers, no additives, no capsule. Free-form amino acid for rapid absorption. Also suitable for cats (feline herpes/upper respiratory support) and horses (immune support) — consult your veterinarian for appropriate dosing by animal weight.

Supplement Facts

Serving size: ¼ level teaspoon | Servings per container: ~378
L-Lysine: dose per serving — see label for exact mg per ¼ tsp
*Daily Value not established.

Suggested use

As a dietary supplement, take ¼ level teaspoon daily, preferably with meals. Mix into water, juice, or any liquid — the powder is virtually tasteless and dissolves easily. Sold by weight, not volume.

Other ingredients

None. 100% pure L-lysine.

Why trust this product

Now Foods has been a trusted leader in quality nutritional supplements since 1968, known for rigorous quality testing, transparent labelling, and exceptional value. This L-lysine is 100% pure pharmaceutical-grade powder with no fillers or additives.

Important

Pregnant or breastfeeding women, and those with kidney disease or impaired kidney function, should consult their healthcare practitioner before use. For pet use, always consult your veterinarian for appropriate dosing. Keep tightly closed and store away from heat and moisture. Keep out of reach of children.