Retatrutide vs. semaglutide: How do they compare for weight loss? 

Weight-loss medication has moved fast over the past few years, and semaglutide—the active ingredient in Ozempic® and Wegovy®—has been at the center of that shift.

Its weight-loss version, Wegovy®, changed the field when it was approved as a once-weekly injection in June 2021. It’s now also available as a daily pill and as a higher-dose injectable version, Wegovy® HD 7.2 mg, all made by the company Novo Nordisk.  

But even as semaglutide keeps evolving, researchers are studying newer medications that may push weight-loss results even further. One of the biggest names to watch is retatrutide, being developed by Eli Lilly, the same company that makes Mounjaro® and Zepbound®.

Retatrutide is making headlines before it’s even approved because it works differently from currently available weight-loss medications. It’s known as a triple agonist, meaning it targets three hormone pathways at once: GLP-1, GIP, and glucagon. Semaglutide targets GLP-1 only, which is already powerful for appetite, fullness, digestion, and blood sugar regulation.

So far, retatrutide studies have shown higher average weight loss than what has typically been seen with semaglutide in separate clinical trials. But retatrutide is still investigational, which means it can’t be prescribed outside clinical trials.

Let’s take a look at how these two medications work, their weight-loss potential, their similarities and differences, and what’s still being studied—including when retatrutide might be approved.

Retatrutide vs. semaglutide: How do they work?

While retatrutide and semaglutide are different, they both work by mimicking hormones your body already makes to manage appetite, digestion, and blood sugar. 

Think of these hormones as messengers. They help tell your brain when you’ve had enough to eat and guide how your body handles food. 

When these hormone receptors are activated by semaglutide or retatrutide, they lower appetite, slow down how quickly your stomach empties, and help regulate blood sugar—making it easier to eat less and feel satisfied for longer. Let’s look at the differences: 

• Semaglutide mimics one hormone, called GLP-1 (glucagon-like peptide-1). This action lowers appetite, slows down how quickly food leaves your stomach, so you stay full longer after eating, and regulates blood sugar.
• Retatrutide targets three hormone receptors: GLP-1, GIP (glucose-dependent insulinotropic polypeptide), and glucagon. GLP-1 and GIP both play roles in how your body responds to food and manages appetite. Glucagon is tied to how your body uses stored energy, including fat. When all three hormones work together, studies describe a synergistic effect that supports weight loss through both appetite and energy use. 

Retatrutide vs. semaglutide: What are the similarities?

Retatrutide and semaglutide are different medications, but they’re built on the same basic idea: mimicking hormone signals your body already uses to manage appetite, digestion, and blood sugar.

Their biggest similarities:

• They both affect appetite and fullness. Semaglutide and retatrutide both activate GLP-1 receptors, which help lower appetite, slow digestion, and support blood sugar regulation after eating.
• They can cause similar digestive side effects. Because both medications affect digestion and appetite signals, the most common side effects tend to be gastrointestinal, including nausea, vomiting, constipation, and stomach discomfort. These are often more noticeable when starting treatment or increasing the dose.
• They both use gradual dose increases. With semaglutide, people typically start at a low dose and increase slowly over time. Retatrutide is being studied with a similar step-up approach in clinical trials. This gradual schedule helps the body adjust and may make side effects easier to manage.
• The injectable versions are taken once weekly. Wegovy® injections are taken once a week, and retatrutide is also being studied as a once-weekly injection. Wegovy is also available as a daily pill.

Retatrutide vs. semaglutide: What are the differences?

Now that you’ve seen where these two overlap, let’s talk about what sets them apart. The differences can shape how each medication works, how it’s taken, and whether it’s available right now.

• They act on a different number of hormone pathways. Semaglutide mimics one hormone pathway: GLP-1. Retatrutide mimics three: GLP-1, GIP, and glucagon. 
• Semaglutide also comes as an oral pill. For weight loss, semaglutide is available as a once-weekly injection and as a daily pill. Retatrutide is only being studied as a once-weekly injection.
• Only semaglutide is currently approved and prescribed. Semaglutide is already FDA-approved and widely prescribed in multiple forms. Retatrutide is still in phase 3 trials, which means it isn’t available outside of research settings yet.

Seeing these differences together can make it easier to understand how each option might fit into your own goals, your routine, and what you’re looking for from treatment.

Retatrutide vs. semaglutide: Which is better for weight loss?

Now, you’re probably wondering how these two actually compare for weight loss. Semaglutide has a strong track record from both clinical trials and real-world use, while retatrutide is still in testing but showing promising results in early studies. This is one of the most exciting things to come out of preliminary research, retatrutide is consistently showing that it beats the current options.

Retatrutide vs. semaglutide: Weight loss potential

Looking at the numbers can give you a clearer sense of what to expect. These results come from different studies, so it helps to treat them as a general guide rather than a direct side-by-side comparison.

Here’s what current research shows:

• Retatrutide: In one recent phase 3 trial, people taking the highest dose (12 mg) lost an average of 28.7% of their body weight at 68 weeks.
• Semaglutide: People taking the 2.4 mg dose of injectable Wegovy^® lose an average of about 15% of their body weight over 104 weeks.
  • A higher-dose version—Wegovy^® HD (7.2 mg)—was recently approved in April 2026 with weight loss results closer to 18.7%. 

Remember, these numbers can help set expectations, but they won’t look exactly the same for everyone. Retatrutide’s results are early phase 3, and real-world results can vary based on factors like starting weight, individual response, and lifestyle changes.

Read more: What is retatrutide? Early tests suggest it may be the strongest GLP-1 yet

Retatrutide vs. semaglutide: Dosage and administration

Both medications are started at the lowest dose and increased over time, a process called titration. This is to minimize side effects and find the most effective, tolerable dose for each person. 

For injections, both medications are designed to be self-administered under the skin (in the abdomen, thigh, or upper arm). Semaglutide comes as a daily pill, as well. 

Here’s how dosing compares:

Semaglutide

• Wegovy^® (injection): Taken once weekly, starting at 0.25 mg once and gradually increased as needed but not earlier than every 4 weeks, up to 7.2 mg, as needed.
• Wegovy^® (pill): Taken once daily, starting with 1.5 mg and gradually increased every 30 days, or as needed but not earlier than every 30 days, up to 25 mg.

Retatrutide: Still being studied, but follows a similar step-up approach in clinical trials.

• Taken as a once-weekly injection
• Doses studied so far include: 1 mg, 4 mg, 8 mg, and up to 12 mg
• Gradual dose increases are used to help the body adjust and reduce side effects

Because retatrutide is still in development, the exact dosing schedule could change before it becomes available, but the general approach is expected to feel similar to current GLP-1 medications.

Read more: Semaglutide: Finding the right dose for weight loss

Who can take retatrutide vs. semaglutide for weight loss?

Thinking about whether one of these could be an option for you? Semaglutide has established guidelines that doctors already use in practice. Retatrutide is still in clinical trials, so while there aren’t official rules yet, the study criteria can give a general idea of who it may be intended for.

For semaglutide, it depends on how it’s prescribed:

• Wegovy^®:
  • A BMI of 30 or higher
  • or a BMI of 27 or higher with at least one weight-related condition, like high blood pressure or high cholesterol
  • Used alongside lifestyle changes for long-term weight management

For retatrutide, again, there are no official prescribing rules yet. But in clinical trials, participants typically have:

• A BMI of 30 or higher
• or a BMI of 27 or higher with at least one weight-related condition, like high blood pressure or high cholesterol

Retatrutide vs. semaglutide: Cost and insurance considerations

What you’ll actually pay for these medications depends on a few key factors—like your insurance coverage, the dose you need, pharmacy pricing, and whether you can use manufacturer savings programs. The big difference right now is that semaglutide is already available, while retatrutide is still in clinical trials and isn’t for sale.

Here’s how current costs compare:

Wegovy^® costs: With and without insurance

The list price is around $1,349 per month, though what you actually pay can vary widely depending on whether you have insurance coverage and how you fill your prescription.

Is Wegovy covered by insurance?

• Private/employer plans: May cover Wegovy^® for weight loss, but prior authorization is usually required.
• Medicare: Does not cover medications prescribed for weight loss.
• Medicaid: Will depend on your state and plan.

Learn more: Wegovy® costs in 2026: With and without insurance coverage

Cost of Wegovy if paying cash: 

If you get your prescription filled through NovoCare Pharmacy, pricing is:

• Wegovy injection:
  • $199/month for 0.25 mg and 0.5 mg 
  • $349/month for 1 mg, 1.7 mg, and 2.4 mg 
  • $399/month for 7.2 mg
• Wegovy pill:
  • $149/month for 1.5 mg
  • $149/month for 4 mg (until 8/31/26 then $199)
  • $299/month for 9 mg and 25 mg

Learn more: What does Wegovy® cost without insurance? How to navigate pricing in 2026

Retatrutide costs: What to expect

Because retatrutide hasn’t been approved yet, there’s no official pricing or insurance coverage information available.

If it does come to market, it will likely be priced similarly to other brand-name weight-loss medications. As with other medications in this category, actual out-of-pocket costs would depend on insurance coverage, manufacturer programs, and pharmacy pricing.

There are some early clues. Zepbound has a list price of around $1,000+ per month, but is also offered for about $299 to $449 per month through LillyDirect. Because retatrutide is being developed by the same company, it may follow a similar direct-to-consumer pricing model—but it’s still too early to know how it will ultimately be priced or covered.

Retatrutide vs. semaglutide: Side effects and safety

Side effects are often one of the biggest things most people want to understand before starting a medication. Semaglutide has been studied for years and is widely used, so its safety profile is well understood. Retatrutide is still in clinical trials, so what we know comes from early data, but the patterns so far look familiar.

Retatrutide vs. semaglutide: Common side effects

Most side effects people experience with these medications are related to digestion. Since both change how your body processes food and signals fullness, it’s normal for things to feel a little different in the beginning as your body adjusts. These tend to show up when starting the medication or increasing the dose, and often become easier to manage over time. 

With semaglutide, common side effects include:

• Nausea
• Vomiting
• Diarrhea
• Constipation
• Abdominal pain

Read more: Semaglutide side effects: Symptom guide & management tips

With retatrutide, early clinical trials show a very similar pattern so far, including:

• Nausea (often the most reported)
• Diarrhea
• Constipation
• Vomiting

Let’s take a look at how some of those most common side effects compare between semaglutide (Wegovy^® 2.4 mg and 7.2 mg) and retatrutide. Keep in mind these are from separate and distinct trials, so they aren’t a direct comparison. 

One newer finding from phase 3 trials is a side effect called dysesthesia, which is a change in how your skin feels, like tingling or sensitivity. It was generally mild and didn’t lead to many people stopping the medication. Wegovy 7.2 mg also saw an increase in this side effect from the previous highest dose of 2.4 mg. You can read more about dysesthesia here.

Side effect	Retatrutide 9 mg	Retatrutide 12 mg	Wegovy® 2.4 mg	Wegovy® 7.2 mg
Nausea	38%	43%	35%	39%
Diarrhea	35%	33%	30%	—
Constipation	22%	25%	19%	20%
Vomiting	20%	21%	16%	22%
Dysesthesia	9%	21%	6%	22%

Read more: Retatrutide side effects and safety: What early research shows so far

Serious side effects and warnings

Serious side effects are rare with these medications, and what has been reported with semaglutide and seen in early retatrutide studies shows a similar pattern. 

Semaglutide

For semaglutide, here are the main risks to keep in mind:

• Thyroid tumor warning: All GLP-1 medications carry the warning of potential thyroid tumors, though this link has only been established in animal studies.
• Pancreatitis: This can feel like strong stomach pain that doesn’t go away and may move to your back, sometimes with vomiting. This needs immediate medical care.
• Gallbladder problems: Pain in the upper abdomen, fever, or yellowing of your skin or eyes should be checked right away.
• Kidney issues: Dehydration from vomiting or diarrhea can strain your kidneys. If you notice swelling, fatigue, or changes in urination, it’s important to contact your provider.
• Low blood sugar: You might feel shaky, dizzy, confused, or notice a fast heartbeat. This is more likely if you’re taking other diabetes medications.
• Vision changes: If your eyesight suddenly becomes blurry or changes, it’s something to get evaluated immediately.
• Heart rate changes: If your heart feels like it’s racing or pounding while you’re at rest, it’s worth getting checked.
• Allergic reactions: Any signs of an allergic reaction, like swelling of your face, trouble breathing, or a severe rash, need emergency care right away.

For complete information on semaglutide side effects, visit the Wegovy^® safety page.

Retatrutide

With retatrutide, there aren’t official safety warnings yet since it’s still in clinical trials. So far, serious side effects haven’t been common, but here’s what an early phase 2 study has shown:

• Pancreatitis: Happened in about 0.4% of people in the study
• Gallbladder problems: Reported in about 1.1% of participants
• Heart rhythm changes: Seen more often with retatrutide, about 6% compared to 3% with placebo
• Liver enzyme changes: Around 1% of participants had increases, but overall liver health stayed stable

These results suggest a low but real chance of serious issues such as pancreatitis, gallbladder problems, severe GI events, and allergic reactions. No cases of medullary thyroid cancer or related conditions were reported in trials, but medications in the GLP-1 class carry a warning based on animal studies, which is something to go over with your doctor if you have a related history. Ultimately, since retatrutide is still being studied, there’s more to learn about its long-term safety.

Read more: Retatrutide side effects and safety: What early research shows so far

The bottom line: Retatrutide looks promising for weight loss, but semaglutide is the option you can use today

At a glance, retatrutide and semaglutide might seem similar, and in many ways, they are. They both work by mimicking hormones that help regulate appetite and how your body processes food. Where they start to differ is in depth. Semaglutide works through one pathway, while retatrutide targets three, adding more layers to how it may influence hunger and energy use.

That difference in how they work is a big part of why retatrutide is getting so much attention, with early studies showing higher average weight loss compared to semaglutide. But at the same time, retatrutide is still in clinical trials, so it’s not something your provider can prescribe right now. Semaglutide, on the other hand, is already approved, widely used, and comes with a clearer understanding of what to expect.

If you want to explore weight loss medications and whether they are right for you, check if you qualify for Noom Med. If you do, you’ll be paired with a licensed clinician who can guide you through your options, prescribe medication if appropriate, and support you with a plan that fits your routine and health goals.

Note: Retatrutide is still in clinical trials and not FDA-approved to treat obesity or for weight loss.