Lysine
Essential amino acid, NMF component. Functional formulation ingredient with no standalone activity on the skin.
Evidence by route
Topical application
Inert formulation ingredient. Safe, no standalone activity.
How to read tiers A–F
- CWeak evidence. In vitro data, open-label studies, or expert consensus
Tolerability and safety
- Irritation potential
- Low
- Allergen risk
- Low
- Pregnancy
- Safe
About this ingredient
Lysine (L-Lysine) is an essential alpha-amino acid and a building block of collagen, elastin, and keratin. In cosmetics it is used as a humectant and conditioning agent. Mechanism. Humectant – pulls moisture from air and retains it in the stratum corneum. Participates in collagen cross-link formation (lysyl oxidase-dependent reaction), which supports skin density. Reduces protein glycation, protecting against age-related changes. Where applied. Serums, creams, masks, shampoos, conditioners (0.5–5%). In Spain in Sesderma Acglicolic and Martiderm lines. Often included in amino-acid complexes with proline, arginine, glycine. Evidence base. Few clinical RCTs on topical lysine; the main base is oral intake for herpes (Cochrane 2017, limited effect) and hair. CIR confirmed safety at cosmetic concentrations. Safety. Hypoallergenic, non-comedogenic. Pregnancy and lactation – topically safe at any stage.
Frequently asked questions
Is Lysine safe during pregnancy?
Lysine is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What is Lysine and what does it do in cosmetics?
Essential amino acid, NMF component.
What's the INCI name for Lysine?
The INCI name is Lysine.
See Lysine in a product composition right on the store page
The Evigrade extension adds an evidence panel to iHerb, Sephora, Druni and 12 more stores. This ingredient and every other one in the product show evidence-tier, allergen risk and pregnancy/lactation flags at a glance.
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Lysine HCl, Macadamia Oil, Magnesium Aspartate, Magnesium PCA, Prunus Domestica Fruit Extract, Agave Tequilana Leaf Extract, Collagen Extract, Histidine
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