WASHINGTON — The Food and Drug Administration has warned the manufacturer of melatonin-laced brownies called “Lazy Larry” that the government considers them unsafe and could seize them from store shelves.

“Lazy Larry” was until July known as “Lazy Cakes,” but the Memphis-based company that makes them, HBB LLC, changed the name after some lawmakers and public officials expressed concerns about the brownies.

Sold in many convenience stores, the sweet treats feature a logo of a smiling – and clearly relaxed – brownie that resembles the children’s TV show character SpongeBob SquarePants.

The FDA said that it does not consider melatonin, a hormone that helps regulate the sleep-wake cycle, to be a safe food additive and that the brownies are “adulterated” because they contain it.