Metabolic peptides

These are the weight and blood-sugar compounds, the most studied and most mainstream peptides in this whole course.

They are built around a gut hormone called GLP-1. When you eat, your gut releases GLP-1. It does three useful things. It tells your brain you are full, slows how fast your stomach empties so you stay full longer, and helps your body manage blood sugar. The problem is that natural GLP-1 is broken down within minutes. These compounds are GLP-1 rebuilt to last for days instead.

Semaglutide (sem-uh-GLOO-tide) is the best known. It mimics GLP-1 with a half-life of about a week, so people inject it once a week. It is approved as a medicine for diabetes and weight loss under brand names you have heard of. Tirzepatide (tur-ZEP-uh-tide) goes a step further. It hits the GLP-1 receptor and a second one called GIP. The double action tends to produce more weight loss. Retatrutide (ret-uh-TROO-tide) is the newer, still-in-trials compound that adds a third target. The early results look strong.

This is the one category where the human evidence is legitimately deep, with large trials behind the major compounds. The flip side is real side effects, nausea especially, which is why protocols start low and increase slowly. That slow ramp is not optional.