Salicylic acid
Salicylic acid is a monohydroxybenzoic acid, a type of phenolic acid and a beta hydroxy acid
Beta hydroxy acid
A beta hydroxy acid or β-hydroxy acid is an organic compound that contains a carboxylic acid functional group and hydroxy functional group separated by two carbon atoms...

. This colorless crystalline organic acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

 is widely used in organic synthesis
Organic synthesis
Organic synthesis is a special branch of chemical synthesis and is concerned with the construction of organic compounds via organic reactions. Organic molecules can often contain a higher level of complexity compared to purely inorganic compounds, so the synthesis of organic compounds has...

 and functions as a plant hormone
Plant hormone
Plant hormones are chemicals that regulate plant growth, which, in the UK, are termed 'plant growth substances'. Plant hormones are signal molecules produced within the plant, and occur in extremely low concentrations. Hormones regulate cellular processes in targeted cells locally and, when moved...

. It is derived from the metabolism of salicin. In addition to being a compound that is chemically similar to but not identical to the active component of aspirin
Aspirin , also known as acetylsalicylic acid , is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. It was discovered by Arthur Eichengrun, a chemist with the German company Bayer...

 (acetylsalicylic acid), it is probably best known for its use in anti-acne treatments.