Skin Conditioning

Lysine Carboxymethyl Cysteinate

INCI: LYSINE CARBOXYMETHYL CYSTEINATE

Reviewed by Daisy · Last updated 14 Aug 2026

A glutathione precursor that strengthens skin's antioxidant defences against environmental stress

Best For Skin Types

All

Addresses

Oxidative stress, Barrier damage, UV sensitivity

Usage Frequency

Daily

What Is Lysine Carboxymethyl Cysteinate?

Lysine carboxymethyl cysteinate (LCC) is a synthetic compound derived from the amino acids lysine and cysteine. It functions as a precursor to glutathione, one of the skin's most important endogenous antioxidants. When applied topically, LCC can penetrate the outer layers of skin and support the body's natural production of glutathione within the epidermis.

Glutathione plays a central role in protecting cells from oxidative stress and free radical damage. By supplying the building blocks for glutathione synthesis, LCC essentially helps strengthen the skin's own antioxidant system rather than simply providing external antioxidant protection.

How It Works

LCC works by delivering the amino acid building blocks (lysine and S-carboxymethyl-cysteine) that skin cells need to synthesise glutathione. Once these compounds reach the epidermis, cells use them to manufacture glutathione internally, which then acts as a powerful scavenger of free radicals and reactive oxygen species generated by UV exposure and other environmental stressors.

Research also suggests LCC may activate autophagy—a cellular housekeeping process—which helps protect the skin barrier by promoting the formation and maintenance of the cornified envelope, the outermost protective layer of skin. This mechanism may explain its benefits for both antioxidant defence and barrier stability.

Clinical Evidence & References

In vitro and ex vivo studies using human keratinocytes and 3D skin tissue models have shown that LCC successfully increases endogenous glutathione levels and penetrates into the epidermis. It has demonstrated protective effects against both blue-light and UVB-induced oxidative stress in cell cultures. In a 3D skin equivalent model exposed to UVB radiation, LCC restored epidermal cell thickness and increased the expression of proteins involved in barrier structure and hydration.

The current evidence base is promising but remains limited to laboratory and tissue models. Human clinical trials are needed to confirm efficacy in real-world conditions and to establish optimal concentrations and usage protocols. The ingredient shows particular potential for photoprotection and barrier support, though more research is required to fully characterise its benefits across different skin conditions.

How to Use

LCC is typically found in serums, moisturisers, and treatment products designed to support antioxidant defence. It works well as part of a broader skincare routine that includes physical or chemical sun protection, as it complements but does not replace sunscreen. Because it supports the skin's own repair mechanisms, consistent daily use is likely to yield the best results.

Safety & Precautions

LCC is a synthetic compound that is generally considered well-tolerated in cosmetic formulations. As with any new skincare ingredient, patch testing is advisable if you have sensitive or reactive skin.

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