Cysteine
Cysteine is a cosmetic ingredient used as an antioxidant, antistatic agent. It is used in 29 products in our dataset. It is regulated in the EU (listed in a Cosmetics Regulation annex). PubMed carries 3,925 studies of its skin or topical use.
| INCI name | CYSTEINE |
| Function | ANTIOXIDANT, ANTISTATIC, HAIR CONDITIONING, HAIR WAVING OR STRAIGHTENING |
| CAS number | 52-90-4 / 3374-22-9 |
| EC number | 200-158-2 / 222-160-2 |
| Prevalence | 29 products (0.03% of dataset) |
| Most used in | Skincare |
| EU status | Restricted (annex ) |
| Scientific studies | 3,925 on PubMed (skin/cosmetic/topical) |
| Monthly searches | 18,100 |
Used in
Serums 24.1%General Moisturizers 6.9%Hair Serums 6.9%Sheet Masks 6.9%Styling Creams & Sprays 6.9%Toners 6.9%
Frequently asked
- What does Cysteine do in skincare?
- Cysteine functions as an antioxidant, antistatic agent in cosmetic formulas.
- Is Cysteine allowed in cosmetics?
- Yes, but it is regulated in the EU — it appears in a Cosmetics Regulation annex with usage conditions.
- What products contain Cysteine?
- It is most commonly found in Skincare products, especially serums (24.1% of its uses).
Manufacturers with experience using Cysteine
Match with vetted US contract manufacturers that have hands-on experience formulating with this ingredient.