WASHINGTON — Scott Gottlieb, the commissioner of the Food and Drug Administration, known for his aggressive efforts to regulate the tobacco and e-cigarette industries, said Tuesday that he would resign at the end of the month.

The reason he gave was family and his weariness with commuting to see his wife and three children, who have remained in their Westport, Connecticut, home since he took office. But his announcement caught many in Washington and the industries he regulates by surprise and raised questions about whether his push to reduce teenage vaping and lower nicotine levels and ban menthol in cigarettes will continue in an administration that generally has a hands-off approach to business.

“It’s critical that his successor champions protecting kids and the rest of the nation against the tobacco epidemic,” said Cliff Douglas, vice president of tobacco control at the American Cancer Society.

Gottlieb has been subject to increasing pressure from some Republicans in Congress and his former associates in the conservative movement for his tough stance against youth vaping and traditional cigarettes. A coalition of influential conservative groups recently asked the White House to block some key parts of the FDA’s strategy to prevent youths from vaping.

Gottlieb said these protests had no role in his departure.

Gottlieb said he planned to advance the FDA’s pending tobacco regulations before he leaves. And he was confident, he said, that the agency’s guidance on restricting flavored e-cigarettes would be issued before he left. He acknowledged, however, that he could not predict the fate of his proposals to ban menthol in cigarettes and reduce nicotine to nonaddictive levels in cigarettes.

“We think this major development will be broadly viewed as a positive for the tobacco industry, although this introduces some uncertainty,” Bonnie Herzog, a managing director of equity research at Wells Fargo Securities, wrote in an email to clients.

Under Gottlieb’s leadership, the FDA approved a record number of generic medicines, new drugs and medical devices. He led the agency into unusual territory, calling for lower drug prices and speaking out about the opioid crisis.

But his record on opioids was mixed, some policy experts said. Although the agency worked to take one powerful addictive painkiller, Opana ER, off the market, it approved Dsuvia, a new form of an extremely potent opioid, for acute pain — which public health advocates feared would be just as dangerous.

This article originally appeared in The New York Times.