Some bodybuilders and athletes use trenbolone esters for their muscle-building and otherwise performance-enhancing effects.  Such use is illegal in the United States and many other countries. The DEA classifies trenbolone and its esters as Schedule III controlled substances under the Controlled Substances Act .  Trenbolone is classified as a Schedule 4 drug in Canada  and a class C drug with no penalty for personal use or possession in the United Kingdom .  Use or possession of steroids without a prescription is a crime in Australia . 
As its production and use increased, public response was mixed. At the same time that DDT was hailed as part of the "world of tomorrow," concerns were expressed about its potential to kill harmless and beneficial insects (particularly pollinators ), birds, fish, and eventually humans. The issue of toxicity was complicated, partly because DDT's effects varied from species to species, and partly because consecutive exposures could accumulate, causing damage comparable to large doses. A number of states attempted to regulate DDT.   In the 1950s the federal government began tightening regulations governing its use.  These events received little attention. Women like Dorothy Colson and Mamie Ella Plyler of Claxton, Georgia gathered evidence about DDT's effects and wrote to the Georgia Department of Public Health, the National Health Council in New York City, and other organizations.