Manufacturing of a controlled substance is the illegal production, preparation, propagation, compounding, conversion, or processing of a drug or controlled substance by any means. This includes manufacture of a controlled substance with or without a valid prescription, or by manipulating the ingredients of a drug or controlled substance to create a new form. Common types of manufacture of a controlled substance include illicit drug production, synthetic drug manufacturing, drug purification, and drug extraction. Manufacture of a controlled substance can also include the distribution of precursors or drug building blocks used to make controlled substances. Examples of precursors include ephedrine, pseudoephedrine, and phenacetin acid.