Search or browse our A-Z lists of active ingredients available in the United States. Access drug & treatment information, identify pills, check interactions and set up personal medication records. Subscribe to our newsletter for the latest medication news, new drug approvals and FDA alerts. The biologically active component of a drug or pesticide is referred to as the active ingredient or the active substance. An active ingredient is any ingredient that provides biologically active or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease or to affect the structure or any function of the body of humans or animals. [1] An active pharmaceutical ingredient (API) is the part of any medication that produces the intended health effects. Learn why it's important to know what that is before taking one. Unfinished drug means an active pharmaceutical ingredient either alone or together with one or more other ingredients but does not include finished drug products. Why your medication contains active and inactive ingredients Active ingredients are the chemical compounds in medicines that have an effect on the body. Essentially, they are the ingredients within your medicine that make the medicine work. Active ingredients are the powerhouse components in skincare products that directly target specific skin concerns, such as acne, pigmentation, fine lines, or dullness. Most medications are made of a combination of active and inactive ingredients. Active pharmaceutical ingredients (also called APIs) provide the therapeutic effects of the medication. An active ingredient is any component that provides pharmacological activity or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease, or to affect the.