Lysine at a glance

  • Amino acid that can enhance skin’s hydration
  • May help skin produce supportive substances that keep it looking smooth and youthful
  • Can be animal-derived or made synthetically in a lab
  • Has many derivatives with skin care benefits including tranexamic acid

Lysine description

Lysine is an amino acid that when applied topically may enhance skin’s hydration by aiding the balanced transport of water through skin’s layers. It also has potential to help skin produce supportive substances that keep it looking smooth and youthful. Lysine can be derived from animals or made synthetically in a lab. The most common manufacturing process for producing lysine is fermentation. Derivatives of lysine, such as tranexamic acid, lysine HCI, lysine carboxymethyl cysteinate, and arginine/lysine polypeptide, are commonly found in skin care serums, moisturizers, and lip treatments. These may offer stronger skin care benefits than lysine itself. The Cosmetic Ingredient Review (CIR) Expert Panel has approved the safe use of lysine in personal care products in concentrations up to 0.7%. Research has shown that amino acids work best for skin when they are combined. Rather than focusing on one particular amino acid, look for skin care formulas with a robust mix of amino acids.

Lysine references

  • Personal Care Products Council, Accessed August 2023, ePublication
  • International Journal of Toxicology, 2013, pages 41S-64S
  • Analytical and Bioanalytical Chemistry, February 2014, pages 380-384

Peer-reviewed, substantiated scientific research is used to assess ingredients in this dictionary. Regulations regarding constraints, permitted concentration levels and availability vary by country and region.

Ingredient ratings


Proven and supported by independent studies. Outstanding active ingredient for most skin types or concerns.


Necessary to improve a formula's texture, stability, or penetration.


Generally non-irritating but may have aesthetic, stability, or other issues that limit its usefulness.


There is a likelihood of irritation. Risk increases when combined with other problematic ingredients.


May cause irritation, inflammation, dryness, etc. May offer benefit in some capability but overall, proven to do more harm than good.


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Not rated

We have not yet rated this ingredient because we have not had a chance to review the research on it.