GLP-1 is a hormone your gut releases after you eat. GLP-1 medications mimic it to help you feel full sooner, slow how fast your stomach empties and quiet constant cravings. Semaglutide acts on GLP-1 receptors. Tirzepatide acts on both GLP-1 and GIP receptors. Both are injected once a week.
- They act on appetite signals in the brain.
- They slow stomach emptying, so you stay full longer.
- They help regulate blood sugar after meals.
- They work best paired with good nutrition, movement and support.
What is GLP-1?
GLP-1, short for glucagon-like peptide-1, is a natural hormone released by your gut when you eat. It tells your brain you are getting full and helps your body manage blood sugar. Your own GLP-1 breaks down within minutes. Medications are designed to last a full week.
How do GLP-1 medications help you lose weight?
| What it does | What you notice |
|---|---|
| Acts on appetite signals in the brain | Fewer cravings and less constant thinking about food |
| Slows stomach emptying | Feeling full sooner and for longer |
| Helps release insulin when blood sugar is high | Steadier energy after meals |
How are semaglutide and tirzepatide different?
Semaglutide mimics GLP-1 alone. Tirzepatide mimics GLP-1 and a second gut hormone, GIP. Both are effective, and your clinician helps you choose based on your health and goals.
Read next: Tirzepatide vs. semaglutide →How long does it take to work?
Many people notice appetite changes within the first few weeks. Weight loss builds over months as your dose steps up.
Frequently asked questions
Is a GLP-1 the same as Ozempic?
Ozempic and Wegovy are brand names for semaglutide. Mounjaro and Zepbound are brand names for tirzepatide. CMWL prescribes compounded semaglutide and tirzepatide, which are not FDA-approved.
Is it a pill or an injection?
The treatments covered in this video are once-weekly injections with a small needle.
Do I still need to change how I eat?
The medication makes eating less easier. Balanced meals with enough protein, plus regular movement, help you get and keep results.
Who prescribes it?
A licensed clinician, after reviewing your health assessment.
Video transcript
The full transcript of the video above, published as text so you can skim, search and quote it.
Show transcript
[Paste the full edited transcript of this video from the CMS Transcript field. Add a timestamp at the start of each new topic so readers can jump to that point.]
Sources
- Drucker DJ. Mechanisms of action and therapeutic application of glucagon-like peptide-1. Cell Metab. 2018;27:740-756.
- Wegovy (semaglutide) injection. Prescribing information. Novo Nordisk.
- Zepbound (tirzepatide) injection. Prescribing information. Eli Lilly and Company.
CMWL Chief Medical Officer and Yale-trained physician. Last reviewed October 14, 2026.
Read full bio →This article is for education only and does not replace personalized medical advice. Compounded medications are not FDA-approved. Talk to a licensed clinician about the risks and benefits of any treatment.
