Novo Nordisk's (NYSE:NVO) oral GLP-1 weight-loss drug Wegovy pill continues to outsell Eli Lilly's recently launched competing tablet, but weekly prescription growth is slowing as the market absorbs a new entrant, according to the latest tracking data. GLP-1, or glucagon-like peptide-1, refers to a class of drugs that mimic a gut hormone to suppress appetite and regulate blood sugar, and has become the most hotly contested space in global pharmaceuticals.