The Twilight Zone (1985) : 1x16

Two twenty-something brothers go to their father's laboratory to steal his fathers' growth serum research and sell for their own profit. They find a web-like material, which tastes great. They find large plants. Some plants have increased in size more than others. For the crime of emotional coldness, Mitchell Chaplin is condemned to social invisibility. For one year he will be branded with an irremovable brand that everyone knows means they must totally ignore him. At first, Chaplin is thrilled at the prospects. A depressed dentist, Myron Mandel, is visited by the Tooth Fairy, who grants him the wish to be incredibly popular and loved. The wish is granted in full force, and soon Mandel can't handle the endless stream of visitors singing his praises.