conditionally

L-Cysteine (L-(+)-Cysteine) is a non-essential sulfur-containing amino acid in humans. L-Cysteine is important for protein synthesis, detoxification, and diverse metabolic functions. Found in beta-keratin, the main protein in nails, skin, and hair, L-Cysteine is important in collagen production, as well as skin elasticity and texture. Also required in the manufacture of amino acid taurine, L-Cysteine is a component of the antioxidant glutathione, and plays a role in the metabolism of essential biochemicals such as coenzyme A, heparin, and biotin.

L-Cysteine hydrochloride hydrate (L-Cysteine hydrochloride monohydrate) is a conditionally essential amino acid, which acts as a precursor for biologically active molecules such as hydrogen sulphide (H2S), taurine and glutathione. L-Cysteine hydrochloride hydrate suppresses ghrelin and reduces appetite in rodents and humans.

L-Cysteine hydrochloride (L-Cysteine HCl) is a conditionally essential amino acid,L-Cysteine hydrochloride suppresses ghrelin and reduces appetite in rodents and humans

4-Hydroxyphenylpropionylglycine, a metabolite derived from the conditionally essential amino acid tyrosine, is synthesized through a process involving aromatic amino acid aminotransferase and tyrosine aminotransferase activities, with subsequent modifications by gut microbiota and glycine conjugation. Additionally, it serves as a metabolite of the phenol phloretin.