Retatrutide (GLP-3) and tirzepatide (GLP-2) are two of the most discussed compounds in the modern weight loss conversation. While both are connected to the GLP-1 category, they do not work in exactly the same way.

This article compares semaglutide, tirzepatide, and retatrutide, including receptor targets, clinical trial results, FDA status, and key differences in 2026.

What are the most common retatrutide side effects? Recent clinical trials highlight primary gastrointestinal responses including nausea and digestive discomfort. Researchers have found that these effects are often dose-dependent, with specific escalation schedules significantly improving patient tolerability and long-term safety profiles.

Current Research on Retatrutide Dosing: Findings from Eli Lilly’s Phase 2 and Phase 3 trials suggest that specific escalation schedules are critical for efficacy. Researchers have documented significant weight loss results and side effect profiles across various studied doses, providing a blueprint for ongoing metabolic studies.

Not all fat-loss peptides work the same way. Some help control appetite, others target fat metabolism, and some are being studied for their effects on visceral fat and body composition. This guide explores Retatrutide (GLP-3), AOD-9604, Tesamorelin, Cagrilintide, MOTS-C, and other popular compounds to help you understand which peptides may work best for different fat-loss goals.

Learn how Retatrutide, often referred to as GLP-3, differs from earlier metabolic peptides and why researchers are paying close attention to its potential impact on body composition, fat mass, lean tissue, energy expenditure, and metabolic regulation.