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 is the pigment found primarily in skin, giving it a brown colour whilst absorbing UV radiation and transforming it into harmless heat energy. It is also found in the hâ¦air, the tissue underlying the iris, and in some parts of the brain. dark hair, dark skin.