Coproporphyrin urine analysis (Coproporphyrin, Urine) is a test that measures the levels of porphyrin compounds in the urine, which are chemical substances that play a role in heme production, a component of hemoglobin. Accumulation of these compounds may indicate disorders in the heme synthesis process, such as porphyria, a group of inherited metabolic disorders. This analysis is also used to detect liver or kidney problems and is considered useful in diagnosing certain types of poisoning, such as lead or mercury poisoning. A 24-hour urine sample is collected to obtain accurate results.