The acronym GLP-1 has become an increasingly popular term in the health arena, especially in the context of weight loss. GLP-1 stands for glucagon-like peptide-1, a naturally occurring hormone whose main role is to regulate blood-sugar levels and appetite.

Last week, Pfizer announced that it would no longer develop danuglipron, a daily GLP-1 weight-loss drug which investors were excited about as a potential blockbuster for the company. This wasn't due to a lack of effectiveness, but because a patient in the trial appeared to have elevated liver enzymes -- a sign of possible damage to cells.