Designer steroids contain chemical structures “derived from, or substantially similar to” anabolic steroids, which became Schedule III controlled substances in the United States in 1990. Chemists create designer steroids by reverse engineering existing drugs, altering their chemical structures, and creating new compounds. Seeking to help curtail problems with steroid-spiked dietary supplements, the Designer Anabolic Steroid Control Act of 2014 classified 25 designer steroids, many contained in supplements, as controlled substances. Previous versions of the 2014 legislation, introduced in 2010 and 2012, had failed to become law despite consistent news accounts of supplements contaminated with conventional and designer steroids, as well as steroid precursors. Guided conceptually by a streams-of-influence model, the present article examines regulatory processes involving designer steroids and discusses limitations on the capacity of news outlets to build policy agendas.