Most conventional medication contain drug substances which are small chemical molecules. Many of these can affect the horse and hundreds of these are routinely screened for by the NHA Laboratory. Many of these newer generation substances which are prohibited and which are of concern are peptide and proteins similar to those found naturally in the horse. This Laboratory is actively involved in a program to extend the screening of racing and out of competition specimens for an increasing number of peptide and protein substances which can affect the horse. These are the future drugs of concern, most of these substances are classified as Class 1, Forbidden Substances within the Rules of the NHA.