Heroin is derived from morphine, which is a natural substance extracted from the seed pods of certain varieties of poppy plants. The process of making heroin involves chemically modifying morphine through acetylation, which increases its potency and makes it more soluble in lipid (fat) tissues, enhancing its ability to cross the blood-brain barrier quickly. Heroin is typically sold as a white or brownish powder or as a black sticky substance known as “black tar heroin.”