In March 2019 Gottlieb pressed for the market withdrawal of certain cosmetics because they were found to contain asbestos, at the same time that he announced a set of new proposals to strengthen oversight of the cosmetics industry, winning praise from legislators who had been pressing for similar reforms. On March 5, 2019, Gottlieb announced his resignation as FDA Commissioner, effective in about a month. He said that he wanted to spend more time with his family. At the time of his resignation, Politico observed, "FDA leaders have typically focused much of their attention on a handful of medical topics, but Gottlieb has been active and aggressive on many issues as commissioner without hewing to a strictly conservative or liberal ideology. It’s an approach that’s won him praise from many in the health sector, while garnering criticism from several of the targeted businesses like tobacco companies and the fast-growing e-cigarette industries." Gottlieb was called “an unusually activist regulator in the Trump administration whose agenda touched everything from tobacco to trans-fats,” and he “wasn't afraid to speak on topics normally seen as a third rail for FDA commissioner, including drug pricing… His most high-profile advocacy came in the area of youth smoking, where he aggressively pressed e-cigarette manufacturers and retailers to halt marketing to teens.” At the same time, other reports observed that Gottlieb left FDA with some of his signature tobacco policies still awaiting full implementation, including his plans to ban menthol in cigarettes. On March 13, 2019, Gottlieb moved to restrict sales of flavored e-cigarettes to try to reduce the soaring rate of teenage vaping. The agency issued a proposal requiring that stores sequester flavored e-cigarettes to areas off-limits to anyone under age 18. The proposal also called for banning the sale of many flavored cigars. Under the policy the FDA would reserve the right to push companies to comply or remove their products from shelves. On March 27, 2019, Gottlieb advanced a new federal rule stipulating, for the first time, that centers that provide mammograms to screen for breast cancer will have to tell women whether they have dense breast tissue, which can increase the risk of cancer and mask tumors. The rule marked the first changes proposed in 20 years to the FDA's regulations on mammography. Upon leaving the FDA, Gottlieb returned to the American Enterprise Institute. In May 2019 he returned to New Enterprise Associates as a partner in the firm's healthcare practice, and serves on the board of two NEA portfolio companies, Aetion, Inc and Tempus Labs, Inc.