The company focuses on vitamins, amino acids, plant extracts, sweeteners and other series of products, which have been widely used in food, health food, cosmetics, feed, veterinary medicine and other industries.
Products
High Purity L-Cystine Powder | ≥98.5% Feed, Food & Supplement Grade | CAS 56-89-3
Description:
Product Overview
L-Cystine is a sulfur-containing amino acid formed by the oxidation of two L-Cysteine molecules joined by a disulfide bridge. As a crystalline, non-essential amino acid, it is particularly abundant in skeletal and connective tissues, hair, and digestive enzymes . L-Cystine serves as a rate-limiting precursor for glutathione (GSH) synthesis, playing a fundamental role in the body’s antioxidant defense system .
At Henan Liyin Biotech, we supply high-purity L-Cystine in the form of a white crystalline powder, with a minimum purity of ≥98.5% (typically 98.5–101.0%), compliant with USP, EP, and FCC standards . Our product is available in Feed Grade, Food Grade, and Supplement Grade to serve applications across animal nutrition, human food, dietary supplements, and personal care.
Why Choose Our L-Cystine?
Verified Purity: Assay ≥98.5% (typically 98.5–101.0% on dried basis), ensuring consistent potency for all applications
Multi-Standard Compliance: Meets USP, EP, and FCC specifications, providing global regulatory acceptance
Superior Bioavailability: The natural L-form is the biologically functional isomer for optimal utilization
Complete Traceability: Each batch is accompanied by a comprehensive Certificate of Analysis (COA), including testing for purity, heavy metals, and microbiological contaminants
Flexible Packaging: Available in packaging options from 1kg to bulk quantities to suit your production needs
Key Functional Properties
Antioxidant Defense & Glutathione Precursor
L-Cystine is a critical precursor for glutathione (GSH), one of the body's most important endogenous antioxidants. It helps protect cells from oxidative damage, supports cellular detoxification processes, and reduces the accumulation of age spots . L-Cystine's disulfide bridges contribute to the stability of protein tertiary structures .
Hair & Skin Health
L-Cystine is found in high concentrations in keratin, the structural protein of hair, skin, and nails. Keratin contains approximately 11% peptide-bound L-cystine, which is connected via disulfide bridges to maintain structural integrity . Clinical research has demonstrated that L-cystine supplementation can increase hair density and improve overall hair appearance in individuals with chronic telogen effluvium or androgenetic alopecia .
Collagen Synergy & Skin Aging
A 2025 clinical trial published in Cosmetics demonstrated that a combination of oral fish collagen peptides and L-cystine improved hydration, cutaneous thickness, and wrinkle reduction in mature women, while also reducing skin redness and improving UV photoprotection in younger women . This dual-market potential highlights L-cystine's value in beauty-from-within formulations.
Detoxification Support
L-Cystine helps eliminate harmful free radicals and peroxides through its role in glutathione production. It also aids in preventing the side effects of chemotherapy and radiation .
Mood & Neurological Health
Research has shown that cysteine can enhance various functions in the central nervous system, including behavioral, biochemical, neurochemical, and redox processes. L-Cysteine depletion can lead to increased oxidative stress in the brain
Quality Assurance & Documentation
All batches undergo rigorous quality control, including:
Assay by HPLC: ≥98.5% (typically 98.5–101.0%)
Heavy Metal Screening: Lead, arsenic, cadmium, mercury, and iron
Microbiological Testing: Salmonella negative, Enterobacteriaceae ≤ 100 CFU/g
Specific Rotation: -215° to -225° verified against USP/EP/FCC specifications
Loss on Drying and Residue on Ignition: To ensure stability and purity
Total Ninhydrin-Positive Substances: To ensure absence of related amino acids
We provide complete documentation with every shipment, including Certificate of Analysis (COA), Material Safety Data Sheet (MSDS), and Allergen Statement. Our GMP-certified production ensures batch-to-batch consistency and traceability.
Sourcing Support
We offer flexible packaging and can provide samples for pre-shipment testing. Our technical team is available to assist with grade selection (Feed, Food, or Supplement Grade), application guidance, and custom formulation support — from R&D trials to full-scale commercial production.
Contact us to discuss your specific L-Cystine requirements or to request samples for your formulations.
Parameters:
-
Parameter
Specification
Product Name
L-Cystine
CAS Number
56-89-3
Molecular Formula
C₆H₁₂N₂O₄S₂
Molecular Weight
240.3 g/mol
Assay (Purity)
≥ 98.5% (typically 98.5–101.0% on dried basis)
Appearance
White crystalline powder or crystals
Available Grades
Feed Grade, Food Grade, Supplement Grade
Standards
USP, EP, FCC
Specific Rotation
[α]²⁰/D -215° to -225°
Loss on Drying
≤ 0.3%
Residue on Ignition
≤ 0.1%
Heavy Metals
≤ 10 ppm
Arsenic (As)
≤ 1 ppm
Lead (Pb)
≤ 5 ppm
Cadmium (Cd)
≤ 10 ppm
Ammonium
≤ 0.02%
Chloride (Cl)
≤ 0.02%
Sulfate (SO₄)
≤ 0.02%
Iron (Fe)
≤ 10 ppm
Microbial Limits
Salmonella negative; Enterobacteriaceae ≤ 100 CFU/g
Packaging Options
1kg, 5kg, 25kg (or as per request)
Documentation
Full COA, MSDS, Allergen Statement
Storage Conditions
Store in a cool, dry place, protected from light and moisture
-
L-Cystine is a sulfur-containing amino acid formed by the oxidation of two cysteine molecules linked by a disulfide bond. As a precursor to glutathione, it plays a vital role in the body's antioxidant defense system and cellular detoxification. Found in high concentrations in keratin, L-Cystine is essential for maintaining healthy hair, skin, and nails. Available in Feed, Food, and Supplement Grades with ≥98.5% purity, backed by full documentation.
-
Animal Feed
L-Cystine has been evaluated by EFSA for use as a feed additive (functional group: flavouring compounds) for all animal species . The FEEDAP Panel concluded that L-Cystine is safe for target species when supplemented at concentrations up to 25 mg/kg complete feed, safe for consumers of products from treated animals, and safe for the environment .
Key Applications:
Feed Nutrition Enhancer: Supports growth, weight gain, and liver and kidney function in poultry and swine
Fur Quality Improvement: Particularly beneficial for fur-bearing animals where sulfur amino acids are essential for coat quality
Regulatory Status: L-Cystine (≥ 98.5%) produced by fermentation with E. coli K-12 (DSM 34232) has been assessed as safe for all animal species. The additive is not considered a skin or eye irritant, nor a skin sensitiser .
Food & Beverage
L-Cystine is widely used in the food industry as a nutritional fortifier and dough conditioner .
Key Applications:
Dough Conditioner & Bread Improver: Strengthens gluten structure and enhances dough handling properties
Flour Treatment Agent: L-Cystine is recognized as a flour treatment agent with designated CAS number 56-89-3
Nutritional Fortification: Used in奶粉母乳化 (humanized milk powder), nutritional supplements, and baked goods
Regulatory Status: L-Cystine is recognized as a food additive with E number E 920 and INS number 921 . It is widely used as a sensory additive (flavouring compound) in food applications .
Dietary Supplements
L-Cystine is a popular ingredient in supplements targeting hair health, skin support, antioxidant defense, and detoxification.
Hair & Nail Health
Clinical research demonstrated that an oral supplement containing L-Cystine significantly increased hair density by 9.9 hairs/cm² after 3 months and 12.3 hairs/cm² after 6 months in patients with chronic telogen effluvium or androgenetic alopecia .
L-Cystine is often combined with micronutrients and botanicals for enhanced hair growth support
Skin Health & Anti-Aging
L-Cystine is used in beauty-from-within formulations, often combined with hydrolyzed collagen, to support skin hydration, elasticity, and wrinkle reduction
It has anti-aging effects that can reduce the accumulation of age spots
Antioxidant & Detoxification
As a precursor to glutathione, L-Cystine supports cellular detoxification and protects against oxidative stress
L-Cystine supports immune system function and assimilation of vitamin B6
Personal Care & Cosmetics
L-Cystine is widely used in cosmetic formulations for its hair-conditioning, antistatic, and skin-conditioning properties .
Hair Care
Serves as a hair conditioning agent, making hair easy to comb, smooth, soft, and shiny
Works in synergy with proteins to restructure, soften, or release curls by dissolving disulfide bridges in hair keratin
Used in shampoos, conditioners, and hair treatments
Skin Care & Cosmetics
- L-Cystine can promote wound healing, prevent skin allergies, and has therapeutic effects on eczema
- Used as an anti-aging agent in skincare formulations
- Functions as an antioxidant to protect skin from environmental stressors
INCI Name: Cysteine
Cosmetic Functions: Hair conditioning, antistatic, skin conditioning, anti-aging, antioxidant
- L-Cystine can promote wound healing, prevent skin allergies, and has therapeutic effects on eczema
Key words:
High Purity L-Cystine Powder | ≥98.5% Feed, Food & Supplement Grade | CAS 56-89-3
Function:
L-Cystine is a sulfur-containing amino acid formed by the oxidation of two cysteine molecules linked by a disulfide bond. As a precursor to glutathione, it plays a vital role in the body's antioxidant defense system and cellular detoxification. Found in high concentrations in keratin, L-Cystine is essential for maintaining healthy hair, skin, and nails. Available in Feed, Food, and Supplement Grades with ≥98.5% purity, backed by full documentation.
Application：
Animal Feed
L-Cystine has been evaluated by EFSA for use as a feed additive (functional group: flavouring compounds) for all animal species . The FEEDAP Panel concluded that L-Cystine is safe for target species when supplemented at concentrations up to 25 mg/kg complete feed, safe for consumers of products from treated animals, and safe for the environment .
Key Applications:
Feed Nutrition Enhancer: Supports growth, weight gain, and liver and kidney function in poultry and swine
Fur Quality Improvement: Particularly beneficial for fur-bearing animals where sulfur amino acids are essential for coat quality
Regulatory Status: L-Cystine (≥ 98.5%) produced by fermentation with E. coli K-12 (DSM 34232) has been assessed as safe for all animal species. The additive is not considered a skin or eye irritant, nor a skin sensitiser .
Food & Beverage
L-Cystine is widely used in the food industry as a nutritional fortifier and dough conditioner .
Key Applications:
Dough Conditioner & Bread Improver: Strengthens gluten structure and enhances dough handling properties
Flour Treatment Agent: L-Cystine is recognized as a flour treatment agent with designated CAS number 56-89-3
Nutritional Fortification: Used in奶粉母乳化 (humanized milk powder), nutritional supplements, and baked goods
Regulatory Status: L-Cystine is recognized as a food additive with E number E 920 and INS number 921 . It is widely used as a sensory additive (flavouring compound) in food applications .
Dietary Supplements
L-Cystine is a popular ingredient in supplements targeting hair health, skin support, antioxidant defense, and detoxification.
Hair & Nail Health
Clinical research demonstrated that an oral supplement containing L-Cystine significantly increased hair density by 9.9 hairs/cm² after 3 months and 12.3 hairs/cm² after 6 months in patients with chronic telogen effluvium or androgenetic alopecia .
L-Cystine is often combined with micronutrients and botanicals for enhanced hair growth support
Skin Health & Anti-Aging
L-Cystine is used in beauty-from-within formulations, often combined with hydrolyzed collagen, to support skin hydration, elasticity, and wrinkle reduction
It has anti-aging effects that can reduce the accumulation of age spots
Antioxidant & Detoxification
As a precursor to glutathione, L-Cystine supports cellular detoxification and protects against oxidative stress
L-Cystine supports immune system function and assimilation of vitamin B6
Personal Care & Cosmetics
L-Cystine is widely used in cosmetic formulations for its hair-conditioning, antistatic, and skin-conditioning properties .
Hair Care
Serves as a hair conditioning agent, making hair easy to comb, smooth, soft, and shiny
Works in synergy with proteins to restructure, soften, or release curls by dissolving disulfide bridges in hair keratin
Used in shampoos, conditioners, and hair treatments
Skin Care & Cosmetics
- L-Cystine can promote wound healing, prevent skin allergies, and has therapeutic effects on eczema
- Used as an anti-aging agent in skincare formulations
- Functions as an antioxidant to protect skin from environmental stressors
INCI Name: Cysteine
Cosmetic Functions: Hair conditioning, antistatic, skin conditioning, anti-aging, antioxidant
About Us
Henan Liyin Biotech Co.,Ltd
We are is established in 2024,located in Zhengzhou,on the banks of the Yellow River-the revered “Mother River “of China .As a specialized supplier of human nutrition and animal health products ,the company focuses on a range of products including vitamins ,amino acids ,plant extracts ,and sweeteners,which are widely used in industries ,such as food ,health supplements,cosmetics ,feed and veterinary medicine .By integrating global product resources with the needs of international clients ,Liyin Biotech provides premium products and professional services tailored to each customer .
FAQ
How to contact ?
You can contact with us by Whatsapp:+86 15824830539, the Average Response Time is 0-4h on Work time, <24h on Non-worktime.
For every inquiry, our sales will provide the one-for-one service for you.
How about the payment terms ?
Normal orders: Company account ;Sample/small orders: Paypal(The 5-10% extrafee).About the payment term, we will negotiate alone.
How to get the samples ?
At the first time ,we can provide you the normal product <30g free sample
How to confirm the Product Quality before placing orders?
1st, you can get free samples for some products, just paythe basic cost for us.
2nd,Also you can send the specification or your quest tous, we will customize the products for you.3rd,We emphasis that our whole company make a livingwith organic chemical and customers, we absolutelyimpossible to sale any fake goods, unqualified goods, it isshame! And None False certificate/lie/illegal thing in oursales net!
Which kind of payment do you accept?
- As usually we use company account ,T/T in advance ,or at least 30% T/T in advance ,the balance can be paid by the copy of B/L
- For some countrys we can accept L/C at sight & DP at sight
- For smaples we can use Paypal (The 5-10% extra fees) or other ways
About the payment term, we will negotiate alone.
How about the shipment ?
1>For bulk goods ,we can use contaioner by sea ,1&20 and 1&40 contaioner
2>For urgently and expensive goods ,we can arrange the air lines for customers choose ,or can as customer required
3>For samples or small quantity goods ,we can use Fedex or other express ways
Related Products
Get Product Information For Free
Note: Please leave your email address, our professionals will contact you as soon as possible!
NEED HELP TO FIND THE RIGHT PRODUCTS WITH OUR EXPERTS?
Contact Us
Phone/WhatsApp:
Email:
About Us
As a specialized supplier of human nutrition and animal health products ,the company focuses on a range of products including vitamins ,amino acids ,plant extracts ,and sweeteners,which are widely used in industries ,such as food ,health supplements,cosmetics ,feed and veterinary medicine .
HUATAO GROUP
Leave Message
Leave your contact information and get a free product quote