The Food and Drug Administration’s approval on Tuesday of a marginally effective drug to enhance the sexual drive of women with low libido came with appropriate safeguards to protect the safety of patients. We will probably never know whether the agency made a purely scientific judgment or whether it was unduly influenced by a campaign, partly financed by the manufacturer and organized with the help of one of its consultants, to depict the agency as gender-biased for never having approved a drug to treat sexual dysfunction in women while approving numerous drugs for men.

Two days after winning approval of its drug, Sprout Pharmaceuticals, a Raleigh, N.C., company with just 34 employees, and Valeant Pharmaceuticals, based in Laval, Quebec, announced that Sprout would be acquired by Valeant for about $1 billion in cash. That is a sizable return on the $100 million that had been invested in Sprout, which was created in 2011.

No doubt there are women who can benefit from the drug — possibly millions of them — but they and others need to be aware of the risks and how to mitigate them.

The drug, known as flibanserin or Addyi, its brand name, changes the levels of three chemicals in the brain in ways that are supposed to enhance libido, although no one knows for sure how it works. The drug was rejected twice by the F.D.A., in 2010 and 2013, but after women told an advisory panel in June how low libido had ruined their lives, the panel recommended approval for premenopausal women with steps taken to limit the risks. This week the agency followed that advice.