Salicylic acid
Salicylic acid is an organic compound with the formula HOC6H4CO2H. A colorless solid, it is a precursor to and a metabolite of aspirin (acetylsalicylic acid). It is a plant hormone. The name is from Latin "salix" for willow tree. It is an ingredient in some anti-acne products. Salts and esters of salicylic acid are known as salicylates.