Cysteine
What Cysteine is & what it does
Cysteine is a sulfur-containing amino acid that occurs naturally in many proteins, including keratin in skin and hair. In cosmetic formulas it acts as a conditioning agent and can support antioxidant chemistry through its reactive thiol group. It is water-soluble and is commonly found in both skin and hair care products.
What does Cysteine do in skincare?
Cysteine is a sulfur-containing amino acid that works as a conditioning agent in cosmetic formulas. Its reactive thiol group can also support antioxidant chemistry within a product. It is found in both skin and hair care formulations.
Is Cysteine vegan?
Cysteine can be derived from both animal and plant or synthetic sources, so whether a specific product is vegan depends on the origin of the ingredient. Many modern cosmetic suppliers offer fermentation-derived or synthetic cysteine. Checking with the brand is the most reliable way to confirm the source.
Is Cysteine natural or synthetic?
Cysteine is a naturally occurring amino acid found in many proteins, including keratin. The cysteine used in cosmetics may be obtained from natural sources or produced through fermentation or synthesis. All forms share the same basic amino-acid structure.
Sunscreens with Cysteine
We rate 8 sunscreens that contain it:
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Sungboon Editor Green Tomato Pore Blurring Suncream
92/100
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JM Solution Double Shield Sun Cream
88/100
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Azio Beauty Age Defy Tinted SPF Perfector
87/100
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Lagom Airy Velvet Sun Stick SPF 50+ PA++++
83/100
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Xaiel Fine Sun CC SPF 50+ / Pa++++
81/100
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JM Solution Baby Fresh Sun Cream 40 PA+++
78/100
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Medicube Collagen Firming Sun Cream
73/100
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Missha M Signature Real Complete BB Cream, SPF 25/pa++
69/100