Sen. Chuck GrassleyCharles (Chuck) Ernest GrassleyRepublicans jockey for position on immigration House clears bill to combat crimes against elderly Grassley: DACA deal wouldn't need border wall funding MORE (R-Iowa) said Congress should do more to prevent the use of synthetic drugs.

“Congress and the Drug Enforcement Administration have to work hard to stay on top of synthetic drugs,” Grassley said. “The cynical makers of these drugs change one chemical to evade existing federal bans.”

Grassley, who will serve as chairman of the Senate Judiciary Committee next year, applauded the administration’s recent action to ban three more synthetic drugs. 

At the end of the year, Congress also passed a bill that would add synthetic steroids to the controlled substances list.