Compare peptide targets and trial questions
The register tells me where a molecule acts. The trial tells me how that activity turned out under particular conditions.
Targets
Semaglutide activates GLP-1 receptors. Tirzepatide activates GIP and GLP-1 receptors; retatrutide adds glucagon-receptor activity. Tesamorelin activates GHRH receptors in the pituitary. The tirzepatide clinical reference, retatrutide structural experiments and tesamorelin pharmacology study describe those engagements.
I’m suspicious of diagrams arranged as an escalator from one to three. The additional target changes the experiment. It provides no automatic guarantee of a better balance between benefit and unwanted effects. Tesamorelin makes the limitation obvious: its receptor belongs to a different hormone system altogether.
Clinical questions
| Compound | A question with human trial evidence here |
|---|---|
| Semaglutide | Cardiovascular events in established disease with overweight or obesity, without diabetes |
| Tirzepatide | Weight change compared directly with semaglutide in adults with obesity |
| Retatrutide | MRI-measured liver fat in overweight or obesity with MASLD, without type 2 diabetes |
| Tesamorelin | Visceral and liver fat in antiretroviral-treated adults with HIV |
The semaglutide-versus-tirzepatide result comes from a direct comparison. Retatrutide’s Phase 2 percentages and tesamorelin’s fat-area measurements come from other settings. I’m comfortable putting these questions beside one another; adding their results to a common score would discard much of their meaning.
Approval and preparation
Semaglutide has approved prescription formulations for type 2 diabetes, chronic weight management, cardiovascular-risk reduction in the specified population and metabolic steatohepatitis. Tirzepatide has prescription approvals for type 2 diabetes, chronic weight management and moderate-to-severe obstructive sleep apnea in adults with obesity.
Tesamorelin’s approval is confined to HIV-associated lipodystrophy in adults. Retatrutide remains investigational and unapproved. The tesamorelin monograph, tirzepatide reference and retatrutide review provide context for their different positions. Research-labelled material has laboratory status. An approved medicine’s record does not establish the identity or quality of material carrying the same compound name.
Adverse findings
Semaglutide’s safety review describes gastrointestinal effects, increased biliary-disease risk and an eye-complication concern with rapid glucose correction in susceptible patients. For tirzepatide, the pooled pancreatitis and biliary analysis found an increased combined gallbladder-or-biliary outcome while the pancreatitis increase did not reach statistical significance.
Retatrutide’s Phase 2 obesity trial recorded dose-related gastrointestinal events and a heart-rate increase. Tesamorelin’s longer HIV study shows fat reaccumulation after stopping. I’d rather see these distinct problems described plainly than reduced to a single safety grade. The individual pages give each finding its population and context.