If you have looked into semaglutide or tirzepatide, you have probably seen the terms GLP-1 and GIP. These are natural hormones your body already makes, and understanding them is the clearest way to understand how these medications work. Here is a plain-language guide.
What are GLP-1 and GIP?
GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide) are incretin hormones. Your gut releases them after you eat, and they help your body respond to food by managing blood sugar, insulin, and appetite. Both break down within minutes naturally, which is why medications based on them are engineered to last much longer.
What GLP-1 does
- It prompts the pancreas to release insulin, but mainly when blood sugar is elevated, which helps avoid dangerous lows.
- It reduces glucagon, a hormone that raises blood sugar.
- It slows how quickly the stomach empties, so you feel full longer after meals.
- It acts on appetite centers in the brain to reduce hunger and cravings.
What GIP does
GIP also stimulates insulin release after meals and plays a role in how the body stores and uses fat. On its own its effect on appetite is modest, but there is growing evidence that combining GIP activity with GLP-1 activity can produce greater results than GLP-1 alone.
How the medications use these hormones
- Semaglutide is a GLP-1 receptor agonist. It mimics natural GLP-1 but resists rapid breakdown, so a single weekly dose keeps appetite and blood-sugar effects going all week.
- Tirzepatide is a dual agonist. It activates both the GLP-1 and GIP receptors at once, combining two pathways in a single molecule.
Does targeting both hormones work better?
In SURMOUNT-5, the first head-to-head trial comparing the two, adults with obesity lost an average of 20.2% of their body weight on tirzepatide versus 13.7% on semaglutide over 72 weeks.[1] Both are highly effective; tirzepatide produced the larger average result in that study. The right choice still depends on the individual, including tolerability, other health conditions, and clinician judgment. Our guide on semaglutide vs. tirzepatide walks through how to decide.
Benefits beyond weight loss
Because these hormones influence blood sugar and metabolism, GLP-1-based medications also improve glycemic control in type 2 diabetes. Semaglutide has additionally shown cardiovascular benefit in high-risk patients: in the SOUL trial, oral semaglutide reduced major cardiovascular events by 14% in people with type 2 diabetes and established heart or kidney disease.[2] You can read more in our summary of the SOUL trial. These cardiovascular findings come from specific high-risk populations and do not automatically apply to everyone.
Accessing treatment at IVUSE+
At IVUSE+, compounded semaglutide and tirzepatide are prescribed and managed through async telehealth by licensed clinicians, with flat, transparent pricing and no subscription. A clinician reviews your history to determine whether treatment is appropriate and which option fits your needs.
References
- Aronne LJ, et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity (SURMOUNT-5). New England Journal of Medicine. 2025;392:2225-2237.
- McGuire DK, et al. Oral Semaglutide and Cardiovascular Outcomes in High-Risk Type 2 Diabetes (SOUL). New England Journal of Medicine. 2025.
This article is for general education and is not medical advice. Compounded medications are not FDA-approved. A licensed clinician determines whether treatment is appropriate for you.
