Common Name(s): L-lysine hydrochloride,lysine hcl,collagen crosslink amino acid

CAS Number: 657-27-2

DESCRIPTION

What It Does: Provides collagen crosslinking substrate and anti-herpes antimicrobial activity from lysine.

Why It's Used: Collagen crosslinking amino acid — lysine is the substrate for lysyl oxidase, the copper-dependent enzyme forming allysine crosslinks that give collagen its tensile strength and structural integrity, making lysine the dietary amino acid most directly supporting collagen mechanical properties.

How It Works: Lysyl oxidase (copper-dependent) converts lysine amino groups to allysine. allysine spontaneously condenses forming desmosine/isodesmosine crosslinks providing collagen tensile strength. anti-herpes from competitive inhibition of arginine (hsv requires arginine for replication). skin conditioning from amino acid humectant.

Typically Found In: Anti-aging collagen support,antiviral skin care,amino acid conditioning

TECHNICAL DETAILS

Primary Category: Active ingredient – cosmetic active

Secondary Functions: Skin conditioning

Application Areas:

Typical Concentration Range: 0.1%–3%

SOURCING & ETHICS

Vegan Status: Conditional - feedstock declaration required

Halal Status: Unverified - feedstock declaration required (plant, animal and petrochemical routes all exist)

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier. [audit 2026-07-29 rev2: origin-dependent: the same inci exists in plant, animal and petrochemical versions and the name does not discriminate. determination requires shariah-panel sign-off.]

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Lysine's anti-herpes activity via arginine competition reflects hsv's metabolic dependency on arginine for capsid protein synthesis — lysine and arginine share intestinal/cellular transport, so high lysine competitively inhibits arginine uptake in virus-infected cells, limiting hsv's arginine supply for capsid assembly. this competitive inhibition makes high-lysine/low-arginine environments virologically restrictive.

Last Verified: 2026-03-12

Primary Sources: Cosing database,griffith et al. lysine anti-herpes study