If you have searched for weight-loss help in the last few years, you have run into the names: Ozempic, Wegovy, Mounjaro, Zepbound, and the newest additions still in trials. All of them belong to a family of medications that work with a hormone your body already makes — GLP-1. Understanding what that hormone does makes the whole category much easier to follow.
What GLP-1 actually does
GLP-1 (glucagon-like peptide-1) is a hormone released in your gut after you eat. It travels to your brain and slows digestion, which is one reason you feel full after a meal. It also helps your pancreas release insulin when blood sugar rises.
- Signals to your brain that you are full, so you eat less without white-knuckling it
- Slows how quickly food leaves your stomach, which stretches out the feeling of fullness
- Supports healthy blood-sugar regulation after meals
The three names to know
Semaglutide is the active ingredient in Ozempic and Wegovy. It mimics GLP-1 and is taken as a once-weekly injection. In clinical trials, adults with obesity lost roughly 15% of their body weight on average over about 68 weeks when combined with diet and lifestyle changes.
Tirzepatide is the active ingredient in Mounjaro and Zepbound. It goes a step further: it mimics GLP-1 and a second hormone called GIP. That dual action is thought to be why trial participants lost roughly 15% to 21% of their body weight over about 17 months, on average, at the studied doses.
Retatrutide is the newest and still investigational. It acts on three hormone pathways — GLP-1, GIP, and glucagon. In an early-stage trial, participants on the highest studied dose lost about 28% of their body weight on average over 48 weeks. It is not yet FDA-approved, and no finished head-to-head trial against tirzepatide has been published.
How a clinician decides what fits you
None of these medications is a one-size-fits-all answer. A licensed clinician reviews your health history, current medications, and goals before anything is prescribed — and may decide a GLP-1 is not the right fit at all. That review is a safety step, not a formality.
- Your full health history, including conditions and current medications
- Whether you meet the medical criteria these medications are studied for
- Which option, if any, matches your goals and risk profile
- A plan for follow-up and dose adjustments over time
The bottom line
GLP-1 medications are a meaningful tool for weight management when they are prescribed and monitored appropriately. They are not a substitute for the habits that keep weight off — but for many adults, they make those habits achievable in the first place.
Educational content only. This article is for general information and is not medical advice, a diagnosis, or a treatment recommendation. It does not replace consultation with a qualified healthcare professional. Prescription medications can cause side effects and are not appropriate for everyone — a licensed clinician evaluates each person individually. Compounded medications are not FDA-approved, and FDA does not verify their safety, effectiveness, or quality. Seek urgent care for severe symptoms.