Description

L-Cysteine is a sulfur-containing, semi-essential amino acid that serves as a critical building block for proteins and a key precursor in numerous biochemical pathways. Its unique thiol (-SH) group makes it a powerful reducing agent and a vital component for maintaining cellular redox balance and protein structure. This versatile compound is essential for manufacturers in the pharmaceutical, nutraceutical, food & beverage, and cosmetic industries, where it functions as an antioxidant, flavor enhancer, and dough conditioner.

Application

• Pharmaceutical & Nutraceutical Ingredients: Used as a precursor for the synthesis of N-acetylcysteine (NAC), a mucolytic and antioxidant drug, and as a direct supplement for its hepatoprotective and detoxifying properties.
• Food & Beverage Additives: Acts as a dough conditioner and reducing agent in baked goods to improve texture and volume, and as a flavor enhancer in savory products and pet food.
• Cosmetic & Personal Care: Incorporated into hair care formulations (permanent wave solutions, hair-strengthening products) and skin care products for its antioxidant and keratin-building properties.
• Biochemical Research & Cell Culture: Serves as a crucial component in cell culture media and as a reducing agent in various biochemical assays and protein studies.
• Animal Feed Nutrition: Added to feed as a nutritional supplement to support feather and hair growth in poultry and other livestock.

Basic Information

Product Name	L-Cysteine
CAS No.	52-90-4
Molecular Formula	C3H7NO2S
Molecular Weight	121.16 g/mol
Synonyms	(2R)-2-Amino-3-sulfanylpropanoic acid; L-2-Amino-3-mercaptopropionic acid; (R)-2-Amino-3-mercaptopropanoic acid; Cysteine; Cys; C; Thioserine; L-Cystein; L-Cysteinum; L-β-Mercaptoalanine; NSC 8744
EINECS	200-158-2

Quality Control

Our L-Cysteine is produced under strict quality management systems. We offer grades compliant with USP, EP, JP, and FCC standards to meet the rigorous demands of pharmaceutical, food, and nutraceutical applications. Every batch undergoes comprehensive analytical testing, including HPLC for purity and chiral purity, heavy metals screening, and microbiological testing. A Certificate of Analysis (COA) is provided with each shipment to guarantee consistency and traceability.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at a controlled room temperature (15-25°C). This product is hygroscopic (moisture-sensitive) and easily oxidized; for long-term storage, consider using an inert atmosphere (e.g., nitrogen or argon purge) in the headspace of the container. Keep away from strong oxidizing agents.

Specification

Item	Specification
Appearance	White crystalline powder
Identification (IR)	Conforms
Assay (HPLC)	98.5% - 101.0%
Specific Rotation	+5.5° to +7.0°
Loss on Drying	≤ 0.5%
Residue on Ignition	≤ 0.1%
Heavy Metals (as Pb)	≤ 10 ppm
Chloride (Cl)	≤ 0.02%
Sulfate (SO4)	≤ 0.02%
Related Substances (HPLC)	Individual impurity ≤ 0.5%, Total impurities ≤ 1.0%
Microbiological Analysis	Total Plate Count < 1000 cfu/g, Yeast & Mold < 100 cfu/g, Absence of E. coli and Salmonella

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.