L-Lysine

Amino acids

Collagen · immunity

Your intake

Today (logged)

0 mg

0% of 1000 mg

Stack potential

0 mg

0% of 1000 mg

Target

1000 mg

Target Range

Where you are on the ladder0% of target

What each level of l-lysine does

Approximate dose-response bands. Individual response varies — these are starting points, not prescriptions.

Severely lowYOU ARE HERE
0 mg – 330 mg
Well below target. Risk of deficiency symptoms tied to collagen · immunity.
Insufficient
330 mg – 1000 mg
Below the recommended daily target. Long-term adequacy not assured.
Adequate
1000 mg – 1500 mg
Daily target met. Standard nutritional support for collagen · immunity.
Therapeutic
1500 mg – 2000 mg
Common for specific health goals. Check the evidence for your situation before sustaining this level.
Diminishing returns
2000 mg – +
Past the point where extra intake typically helps. Evidence for further benefit is thin.

Overview

Essential amino acid; the rate-limiting amino acid in many cereal-based diets. Required for protein synthesis, collagen cross-linking, and carnitine biosynthesis. Most commonly supplemented for HSV (cold sore / genital herpes) prophylaxis — lysine competes with arginine, which HSV requires for replication.

Functions

●Essential amino acid for protein synthesis
●Hydroxylysine residues cross-link collagen and elastin
●Precursor for carnitine biosynthesis
●Substrate for histone methylation (epigenetic regulation)
●Required for calcium absorption (older mechanistic data)

Mechanism

Lysine cannot be synthesised by humans — must come from diet. Lysyl oxidase (copper-dependent) cross-links collagen via lysine and hydroxylysine residues, providing tensile strength to connective tissue. In HSV prophylaxis, lysine competes with arginine for cellular uptake (CAT-1 transporter) and for incorporation into the viral capsid — high lysine / low arginine ratio reduces viral replication.

Benefits

●Reduces HSV outbreak frequency and severity (1–3 g/day, with low arginine)
●Modestly improves calcium retention (older studies)
●Required for normal growth in children
●Supplementation in cereal-heavy populations improves protein status (lysine-fortification programs)

Deficiency

Rare in protein-adequate populations; can occur on cereal-based diets without animal protein, eggs, or legumes.

Signs

●Fatigue, slow recovery from illness
●Slow growth in children
●Impaired immunity
●Anemia (severe)

At-risk groups

●Strict vegetarians on cereal-dominant diets without legumes
●Children in low-protein populations
●Lysinuric protein intolerance (genetic)

Excess

Well-tolerated up to ~6 g/day. Long-term high-dose use without copper monitoring is theoretically problematic.

Signs

●GI upset at multi-gram doses
●Possible reduced arginine availability (relevant in CV protocols)
●Theoretical gallstone risk with very prolonged high doses

Forms

L-lysine HCl
Standard supplement form
L-lysine monohydrochloride
Stable, water-soluble; same as above in practice
Lysine + vitamin C topical (Pauling protocol)
Historical CV/connective tissue use; thin evidence

Food sources

Cooked chicken breast · 3 oz2.4 g
Cooked beef · 3 oz2.5 g
Cooked tuna · 3 oz2.4 g
Cottage cheese · 1/2 cup1.4 g
Lentils (cooked) · 1 cup1.2 g
Eggs (whole) · 1 large0.5 g

Supplement forms

L-lysine HCl at 1–3 g/day during outbreak prodrome (HSV use case). For general protein adequacy, food-first. Avoid stacking with high-dose arginine if HSV-prone — the ratio matters more than absolute amounts.

Bioavailability

Well-absorbed via cationic amino acid transporters. Competes with arginine for the same transporter — meaningful in HSV prophylaxis. Take on empty stomach for the antiviral context to maximise plasma peak.

Longevity relevance

Adequacy is essential (it's an essential amino acid). Connective tissue cross-linking and bone health both depend on lysine availability. No supplementation signal for healthspan in well-fed adults.