It is a narcotic and may cause withdrawal symptoms if it is stopped too abruptly. Although Norco withdrawal can be quite unpleasant and uncomfortable, you can be assured that it is not life threatening. Norco withdrawal is possible in people who abuse Norco and in people who take Norco for a legitimate medical use.
Definition of melanin for English Language Learners. : a dark brown or black substance that is a natural part of people's skin, hair, and eyes.
Melanin /ËmÉlÉnÉªn/ (Greek: Î¼Î­Î»Î±Ï - melas, black, dark) is a broad term for a group of natural pigments found in most organisms (arachnids are one of the few groups in which it has not been detected).Melanin is produced by the oxidation of the amino acid tyrosine, followed by polymerization.he most common type of melanin is eumelanin. There are two types of eumelaninâbrown eumelanin and black eumelanin. Pheomelanin is a cysteine-containing red polymer of benzothiazine units largely responsible for red hair, among other pigmentation. Neuromelanin is found in the brain, though its function remains obscure.