L-Cysteine Hydrochloride Monohydrate丨CAS 7048-04-6

L-Cysteine hydrochloride monohydrate丨7048-04-6 is a derivative of the amino acid cysteine and is widely used in various biochemical, pharmaceutical, and cosmetic applications. It is the hydrochloride salt of L-cysteine, which contains an additional water molecule in its crystalline form, making it monohydrate. Cysteine itself is a sulfur-containing amino acid known for its role in protein synthesis, detoxification, and antioxidant activity. The hydrochloride form of L-cysteine is commonly used because it is more soluble in water and more stable compared to its free base form.
L-cysteine hydrochloride monohydrate is a white, crystalline powder that is soluble in water, making it ideal for use in various aqueous-based formulations. It is commonly used in pharmaceuticals, nutraceuticals, cosmetic formulations, and industrial processes.

1. Pharmaceutical Applications
L-Cysteine hydrochloride monohydrate丨7048-04-6 plays an important role in pharmaceutical formulations and is used in the production of medications that require cysteine's antioxidant properties.
● Antioxidant and Detoxification: L-cysteine is a precursor to glutathione, one of the body's most important antioxidants. Due to this, L-cysteine hydrochloride is used in treatments aimed at detoxification and liver health. It is often incorporated into formulations designed to treat acetaminophen (paracetamol) poisoning, as it helps to restore glutathione levels in the liver and prevents liver damage.
● Cystic Fibrosis Treatment: L-cysteine hydrochloride is used in the treatment of cystic fibrosis, where it helps break down mucus and improve lung function. By aiding in the breakdown of thick mucus, it facilitates easier breathing and can reduce the frequency of lung infections in patients with this condition.
● Amino Acid Supplements: In supplement form, L-cysteine hydrochloride is used to support protein synthesis, skin health, and hair growth. It is often found in nourishing supplements due to its role in collagen production and its ability to strengthen hair follicles.
2. Cosmetic and Personal Care Applications
In the cosmetic industry, L-cysteine hydrochloride monohydrate is a versatile ingredient due to its antioxidant, anti-aging, and hair health benefits.
● Skin Care: L-cysteine is used in anti-aging products and skin care formulations due to its role in collagen production, which is essential for maintaining the elasticity and firmness of the skin. By enhancing skin regeneration, it helps improve the overall appearance and texture of the skin, reducing the visible signs of aging.
● Hair Care: L-cysteine is a key component in hair care products such as shampoos and conditioners. It helps strengthen the hair shaft by supporting keratin formation, which leads to healthier, shinier, and stronger hair. Some products use L-cysteine hydrochloride as a key ingredient in treatments aimed at reducing hair loss and promoting hair growth.
● Nail Health: The benefits of L-cysteine are also extended to nail care, where it helps support the growth of stronger and more durable nails by promoting keratin synthesis.
3. Food and Nutraceutical Applications
L-Cysteine hydrochloride monohydrate丨7048-04-6 is used as a food additive and in nutraceutical products due to its antioxidant properties and its ability to support protein synthesis.
● Food Additive: In the food industry, L-cysteine is used as a dough conditioner in baking, where it helps improve the texture of baked goods by making the dough more elastic and easier to handle. It is especially useful in bread production, where it can improve the dough's stretchability and bread softness.
● Nutraceuticals: As a dietary supplement, L-cysteine supports immune system health, liver function, and detoxification. It is often found in supplements aimed at promoting overall well-being and anti-aging benefits.
4. Industrial Applications
In addition to its use in pharmaceuticals, cosmetics, and food products, L-cysteine hydrochloride monohydrate has some applications in the chemical industry.
● Production of Chemicals: L-cysteine hydrochloride can be used as a precursor for the synthesis of various biochemicals and pharmaceutical intermediates. Its ability to donate sulfur groups makes it useful in the creation of sulfur-containing compounds used in various industrial processes.
● Leather Processing: L-cysteine is sometimes used in the leather industry to soften and treat leather. Its ability to break down certain compounds and improve texture has made it an important component in leather production.

1. Antioxidant Properties
L-Cysteine is a precursor to glutathione, a critical antioxidant that helps protect cells from oxidative stress and damage. By contributing to the formation of glutathione, L-cysteine hydrochloride offers numerous health benefits:
● Liver Detoxification: It helps detoxify the liver by promoting the production of glutathione, which neutralizes harmful free radicals and toxins.
● Protecting Against Oxidative Damage: By boosting glutathione levels, L-cysteine helps protect cells from oxidative stress, which can contribute to aging, cancer, and various diseases.
2. Promotes Hair and Skin Health
● Keratin Production: L-cysteine plays an essential role in the formation of keratin, a key protein in hair, skin, and nails. By promoting keratin production, it supports stronger, healthier hair and nails, while also promoting younger-looking skin.
● Anti-aging Effects: As a component of collagen, L-cysteine helps reduce the visible signs of aging, including wrinkles and fine lines, by supporting skin regeneration and elasticity.
3. Supports Protein Synthesis
L-Cysteine is an important amino acid involved in the synthesis of proteins, particularly those with sulfur-containing structures like keratin and collagen. This makes it crucial for maintaining the health and function of connective tissues, including skin, hair, and nails.
● Wound Healing: Because of its role in collagen production, L-cysteine can support wound healing and tissue repair.
4. Helps in Detoxification
L-Cysteine plays a key role in detoxification processes in the body. By supporting the production of glutathione, it aids in the neutralization of toxins and free radicals in the body, particularly in the liver. This detoxifying effect makes L-cysteine hydrochloride useful for individuals looking to boost liver function or detoxify from environmental pollutants or harmful substances.
5. Improves Respiratory Health
L-Cysteine hydrochloride monohydrate丨7048-04-6 has been found to break down mucus and thin respiratory secretions, which is particularly useful for individuals with chronic respiratory conditions like cystic fibrosis or chronic obstructive pulmonary disease (COPD). This helps to clear the airways and reduce the risk of infections.

L-Cysteine hydrochloride monohydrate丨7048-04-6 is a highly versatile compound with numerous applications in the pharmaceutical, cosmetic, food, and industrial sectors. It is primarily valued for its role in providing antioxidant protection, supporting protein synthesis, promoting hair and skin health, and aiding in detoxification processes. Due to its biocompatibility and solubility, it is widely used in supplements, skincare products, and pharmaceutical formulations.