Originally approved to help with excess weight and obesity, Wegovy and Ozempic, have become synonymous with weight loss fads. Here's what you need to know.

Semaglutide, the underlying drug marketed as Ozempic and Wegovy, works by mimicking a hormone that triggers the body to feel full. When the drug interacts with a receptor in the stomach, patients feel full sooner and for a longer period of time after eating. The drug does not cause weight loss directly – instead, it makes you want to eat less.

Sima Sistani, who took up the CEO post at WW International two-and-a-half years ago, is out, according to the company.

Poor purity can cause patients to experience fever, chills, nausea, skin irritation, infections and low blood pressure.

Zealand Pharma CEO Adam Steensberg said Friday that the company is working on a next-generation weight loss drug that’s designed to work differently from those currently on the market and with the potential for fewer side effects.

Peptide companies' are creating knock-off versions of these drugs that have not been approved by the FDA and contain ingredients that may lack the purity of the branded medications.