Ozempic, Zepbound, and Retatrutide: What's Actually Different?

Ozempic. Wegovy. Mounjaro. Zepbound. And now, retatrutide.

If your head is spinning, you are in good company. Everybody lumps these together as “GLP-1s,” and then the conversation stalls, because nobody can say how they actually differ.

Here is the simple version. By the end, you will be able to explain it to a friend at dinner.

The short version

• Ozempic and Wegovy are the same drug. Mounjaro and Zepbound are the same drug.
• Think of each generation as turning more dials.
• In a head-to-head test, the two-dial medicine beat the one-dial medicine.
• Retatrutide is the newest, with three dials, and it is still in research.

First, the decoder ring

Most of the confusion is just names. A drug has two names: the brand name on the box, and the real name of what is inside. Here is who is who:

Ozempic and Wegovy are the same medicine, semaglutide. They are sold with different doses and different approved uses. Ozempic was approved in 2017 for type 2 diabetes, and Wegovy in 2021 for weight management.

The same goes for tirzepatide: it is sold as Mounjaro for type 2 diabetes and as Zepbound for chronic weight management. So when someone says, “Is Zepbound the same as Mounjaro?” you now know the answer. Same medicine, different label.

Here’s the “dials” idea

One, two, or three signals

Medicine	Signals
Semaglutide	GLP-1
Tirzepatide	GLP-1GIP
Retatrutide	GLP-1GIPGlucagon

Imagine your appetite and metabolism as a control panel with a bunch of dials. Each generation of medicine turns more of them. That is the whole difference.

One dial: Ozempic and Wegovy (semaglutide)

This is the medicine that made GLP-1 a household word. It copies your natural GLP-1 and turns the “I’m full” dial: quieter appetite, slower digestion, better blood sugar.

In a landmark study of nearly 2,000 adults, people lost an average of about 15% of their body weight over 68 weeks. People on placebo lost about 2%. For a single dial, that was a breakthrough, and it became the bar every newer medicine is measured against.

Two dials: Mounjaro and Zepbound (tirzepatide)

This one keeps the GLP-1 dial and adds a second, called GIP. GIP is another gut hormone.

Researchers think it supports what GLP-1 is already doing: it appears to calm nausea and suppress appetite, which helps the pair work better together.

Did the second dial really matter? Yes. In a head-to-head study, people on the two-dial medicine lost about 20% of their body weight at 72 weeks, compared with about 14% on the one-dial medicine. People on the two-dial version were also more likely to hit big milestones, like losing 15%, 20%, or even 25% of their weight.

Three dials: retatrutide

Now add a third dial, called glucagon. In plain English, its role here is to nudge your body toward using more energy. In earlier research, retatrutide cut food intake and also increased energy use, which is a different angle from the first two.

In its 48-week early-stage study, people lost about 23% to 24% of their body weight on the top two doses. Larger, later-stage studies have gone further, and Article 3 covers those results in detail.

Here is the catch: retatrutide is still being studied. You will not find it at your pharmacy yet.

The cheat sheet

One honest note: these numbers come from different studies, with different people and different timelines. So think of the table as a trend, not a race. The only true head-to-head here is the one-dial medicine versus the two-dial medicine.

The trend is still clear. Every time scientists added a dial, results got stronger.

What this means for you

The next time you hear one of these names, think of a timeline. Step one was Ozempic and Wegovy. Step two was Mounjaro and Zepbound. Step three is retatrutide, and a lot of people are watching it closely.

If you are curious about this class of medicine, that timeline gives you the language to ask better questions. How many dials? What was studied? How strong were the results?

Quick answers

Are Ozempic and Wegovy different drugs?

No. Both contain semaglutide. They have different doses and approved uses.

Are Mounjaro and Zepbound different drugs?

No. Both contain tirzepatide.

Which one is strongest?

In head-to-head research, the two-dial medicine beat the one-dial medicine. Retatrutide’s results are the largest so far, but they come from different studies.

Is retatrutide available?

Not yet. Its maker, Eli Lilly, plans to ask the FDA for approval in the first quarter of 2027.

Your next step

Not sure what makes sense for your goals? Work with me and we will walk through it together, in plain English.

Where the numbers come from: sources [1] [2] [4] [13] [29] [30] [31] [33] [34] [35]

Where to go next

Now that the dials make sense, see what retatrutide studies actually reported — and what triple agonism changes day to day.

• Retatrutide for beginners
• What retatrutide actually does for you

Back to the GLP-1 Field Guide