Ingredient

L-Cystine

L-cysteine is an amino acid component necessary for protein synthesis.

See medicines used for Others & Special
All medicines
36
Single ingredient
7
Combination
29
Prescription medication
2
OTC medication
34

MFDS ingredient code M103054

What does it do?

L-cysteine is a type of amino acid that belongs to the class of amino acid preparations, primarily used to support skin and hair health. This component plays an important role in forming proteins in the body and is also used as a nutritional supplement.

L-cysteine participates in protein synthesis in the body, reinforcing the structure of skin and hair. Additionally, it reduces cellular damage through its antioxidant action and supports tissue regeneration.

Commonly used for

Approved uses differ by product. Check each product's information for its actual use.

Good to know

L-cysteine is a form consisting of two cysteine molecules bonded together, which provides a more stable structure compared to single cysteine. As a result, it is especially effective for skin and hair health and possesses characteristics that distinguish it from other amino acids.

Medicines containing this ingredient

Even with the same ingredient, strength, dosage form and how it is taken can differ.

Category
Dosage form
Strength
Category

36 total

View more

Even with the same ingredient, dosage and approved uses can differ by strength, dosage form and combined ingredients. Check each product's information before taking it.

Combined ingredients

Ingredients used together with this ingredient in combination products.

Questions about this ingredient

  • QI saw it in a hair loss medication; does it have any effect?

    L-Cystine is described as a component that participates in protein synthesis, reinforcing the structure of skin and hair and supporting tissue regeneration. However, the effects can differ among individuals and the causes of hair loss are varied, so if symptoms persist, consider consulting a dermatologist to identify the underlying cause.

    Answers 1 · 2026.09.14

  • QIs L-cystine different from L-cysteine?

    They are different. L-Cystine is a form composed of two cysteine molecules, which is explained to be more structurally stable than a single cysteine. It is primarily used in medications or nutritional supplements aimed at supporting skin and hair health.

    Answers 1 · 2026.09.14

For anything that needs medical judgment, consult a doctor or pharmacist.

SourceKorea Ministry of Food and Drug Safety (Drug Safety Korea)

This drug information is based on data provided by the Korea Ministry of Food and Drug Safety.
Consult a doctor or pharmacist for accurate dosage, administration, and usage instructions.