Understanding GLP-1 Drugs: Benefits, Side Effects, and Who Should Consider Them

GLP-1 receptor agonists like semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound) have emerged as transformative treatments for type 2 diabetes and obesity. Here's what patients and clinicians need to know:

Mechanism of Action

These drugs mimic the glucagon-like peptide-1 hormone, stimulating insulin secretion, suppressing glucagon, slowing gastric emptying, and reducing appetite through central nervous system effects. The result is significant reductions in blood glucose and body weight.

Clinical Efficacy

The SURMOUNT trials for tirzepatide showed average weight reductions of 20–22% over 72 weeks. The SELECT trial demonstrated a 20% reduction in major adverse cardiovascular events with semaglutide in non-diabetic obese patients — a landmark result.

Common Side Effects

Nausea, vomiting, diarrhea, and constipation are the most frequent adverse effects, typically dose-dependent and improving over time. Rare but serious risks include pancreatitis and, in rodent studies, thyroid C-cell tumors (significance in humans remains under study).