White willow bark is the original aspirin. The medicinal use of willow bark dates back to the Greek physician Hippocrates (400 B.C.), who advised his patients to chew on willow bark to reduce fever and inflammation. It became really popular in the 1800's-so popular that it caught the interest of the German company Bayer. Bayer found a created a synthetic derivative called acetylsalicylic acid (aspirin) and mass-produced it. Find out more about the herb white willow bark.