Zeller credited Gottlieb for advocating for the nicotine regulation within the Trump White House, after the Obama administration had fallen short. Obama officials had promised Zeller they would back rules to curb nicotine and menthol.

The FDA's proposed rule would slash nicotine levels in cigarettes, most cigars and other combustible tobacco products, but not vapes, hookahs or Zyn.

Temple pulmonologist Dr. Jamie Garfield says the proposed regulation is an effective harm reduction strategy, but suggests it will take a significant lobbying effort for it to go into effect.