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Cysteine Hydrochloride

Medically reviewed by Last updated on Jul 3, 2023.

Excipient (pharmacologically inactive substance)

What is it?

Cysteine is an amino acid. It is one of the main building block of proteins that are used in the body. When taken as a supplement, it is usually in the form of N-acetyl-L-cysteine (NAC). The body turns NAC into cysteine and then glutathione, a strong antioxidant. Cysteine has a wide range of uses. In the pharmaceutical industry it is used to improve hepatic function and pigmentation. In clinical nutrition L-Cysteine is used as an antioxidant agent. In the food industry it is used as an antioxidant for natural fruit juice products. It may also be used as an additive to amino acid injections to meet essential nutritional requirements in intravenous total parenteral nutrition.[1]

List of medications using Cysteine Hydrochloride


  1. [1] L-Cysteine Hydrocholride. Accessed March 30, 2104.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.