BALTIMORE — At Everest Greenish Grocery, a brightly lit store on a faded corner of this city, nothing is more popular than a chocolate-flavored little cigar. They are displayed just above the Hershey bars along with their colorful cigarillo cousins — white grape, strawberry, pineapple and Da Bomb Blueberry. And they were completely sold out by 9 one recent evening, snapped up by young people dropping by for a snack or stopping in during a night of bar hopping.

“Sorry, no more chocolate,” the night clerk, Qudrad Bari, apologetically told a young woman holding a fruit drink.

In 2009, Congress passed a landmark law intended to eliminate an important gateway to smoking for young people by banning virtually all the flavors in cigarettes that advocates said tempted them. Health experts predicted that the change would lead to deep reductions in youth smoking. But the law was silent on flavors in cigars and a number of other tobacco products, instead giving the Food and Drug Administration broad discretion to decide whether to regulate them.

Four years later, the agency has yet to assert that authority. And a rainbow of cheap flavored cigars and cigarillos, including some that look like cigarettes, line the shelves of convenience stores and gas stations, often right next to the candy. F.D.A. officials say they intend to regulate cigars and other tobacco products, but they do not say how or when. Smoking opponents contend that the agency’s delay is threatening recent progress in reducing smoking among young people.