Mounjaro vs Ozempic vs Wegovy vs Zepbound: Complete 2026 Comparison

If you’re trying to figure out the difference between Mounjaro, Ozempic, Wegovy, and Zepbound, you’re not alone. These four medications dominate the GLP-1 conversation, and the overlap in names, active ingredients, and uses makes it genuinely confusing.

I’ve been on Mounjaro personally since 2024 and track my progress with DEXA scans, so I have both a research perspective and a firsthand one. This guide breaks down everything — how they work, what they cost, what the clinical trials actually showed, and how to decide which one is right for you.

TL;DR — Quick Summary

• Mounjaro (tirzepatide) and Zepbound (also tirzepatide) are the same molecule. Mounjaro is approved for type 2 diabetes; Zepbound is approved for weight management.
• Ozempic (semaglutide) and Wegovy (also semaglutide) are the same molecule. Ozempic is approved for type 2 diabetes; Wegovy is approved for weight management.
• Tirzepatide (Mounjaro/Zepbound) produces more weight loss than semaglutide (Ozempic/Wegovy) in head-to-head and cross-trial comparisons — roughly 22.5% vs 15% of body weight.
• Cost is the real barrier. Brand-name prices range from $892 to $1,349 per month without insurance. Compounded versions run $149–$399/month through telehealth providers.
• Side effects are similar across all four — mostly GI (nausea, constipation, diarrhea), typically worst in the first few weeks of each dose increase.

What Each Medication Actually Is

The first thing to understand is that there are really only two molecules here, sold under four brand names.

Tirzepatide (Mounjaro & Zepbound)

Tirzepatide is a dual GIP/GLP-1 receptor agonist made by Eli Lilly. In plain terms: it activates two hormones involved in blood sugar regulation and appetite — GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide).

Think of it like having two keys turning two locks at once. GLP-1 slows gastric emptying, reduces appetite, and improves insulin sensitivity. GIP adds additional appetite suppression and may play a role in how your body stores and burns fat.

• Mounjaro — FDA-approved for type 2 diabetes (2022). Prescribed off-label for weight loss.
• Zepbound — FDA-approved specifically for chronic weight management (2023). Same drug, same doses, different label.

Available doses: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, 15 mg (weekly injection).

Semaglutide (Ozempic & Wegovy)

Semaglutide is a GLP-1 receptor agonist made by Novo Nordisk. It targets one hormone — GLP-1 — which slows digestion, reduces hunger signals to the brain, and improves how your body handles insulin.

• Ozempic — FDA-approved for type 2 diabetes (2017). Widely prescribed off-label for weight loss.
• Wegovy — FDA-approved for chronic weight management (2021). Same active ingredient, higher maximum dose.

Ozempic doses: 0.25 mg, 0.5 mg, 1 mg, 2 mg (weekly injection). Wegovy doses: 0.25 mg, 0.5 mg, 1 mg, 1.7 mg, 2.4 mg (weekly injection).

The Key Difference: Dual Action vs Single Action

The core distinction is that tirzepatide works on two receptors (GIP + GLP-1) while semaglutide works on one (GLP-1 only). This dual mechanism is widely believed to explain why tirzepatide produces greater weight loss in clinical trials. The GIP receptor activation appears to enhance fat metabolism and appetite suppression beyond what GLP-1 alone achieves.

Weight Loss Efficacy: What the Clinical Trials Show

This is where the data gets compelling. Both drugs produce significant weight loss, but tirzepatide has a clear edge.

SURMOUNT Trials (Tirzepatide / Mounjaro / Zepbound)

The SURMOUNT-1 trial (published in the New England Journal of Medicine, 2022) studied tirzepatide in adults with obesity or overweight (BMI ≥ 30, or ≥ 27 with a weight-related condition) who did not have diabetes.

Results at 72 weeks:

• 5 mg dose: 15.0% body weight loss
• 10 mg dose: 19.5% body weight loss
• 15 mg dose: 22.5% body weight loss
• Placebo: 3.1% body weight loss

Over one-third of participants on the 15 mg dose lost more than 25% of their body weight. These results were unprecedented for a pharmaceutical intervention at the time of publication.

STEP Trials (Semaglutide / Wegovy)

The STEP 1 trial (also published in the New England Journal of Medicine, 2021) studied semaglutide 2.4 mg in a similar population — adults with obesity or overweight without diabetes.

Results at 68 weeks:

• 2.4 mg dose: 14.9% body weight loss
• Placebo: 2.4% body weight loss

About one-third of participants lost more than 20% of their body weight.

Head-to-Head: SURMOUNT-5

The SURMOUNT-5 trial directly compared tirzepatide (up to 15 mg) against semaglutide (up to 2.4 mg) over 72 weeks in adults with obesity.

Results:

• Tirzepatide group: 20.2% body weight loss
• Semaglutide group: 13.7% body weight loss

This was a statistically significant difference. Tirzepatide produced roughly 47% more weight loss than semaglutide when compared directly.

Weight Loss Comparison Table

Important context: These are averages. Individual results vary significantly based on dose, diet, exercise, starting weight, and how long you stay on treatment. Some people respond better to semaglutide than tirzepatide, and vice versa.

Cost Comparison: Brand vs Compounded (2025–2026 Prices)

Cost is the single biggest factor for most people. Here’s what you’re looking at.

A Note on Compounded GLP-1s

Compounded tirzepatide and semaglutide are produced by compounding pharmacies when the brand-name versions are in shortage. The FDA has allowed this under its shortage policy. These are the same active molecules, but they’re mixed by compounding pharmacies rather than manufactured by Eli Lilly or Novo Nordisk.

The regulatory situation here is evolving. The FDA has periodically updated the shortage status of these medications, which affects whether compounding is permitted. Before starting a compounded version, verify the current shortage status and make sure your provider uses a 503B-registered outsourcing facility, which is subject to FDA inspection.

Compounded versions are significantly cheaper and are the route most people without insurance coverage take.

Manufacturer Savings Programs

Both manufacturers offer savings cards:

• Eli Lilly (Mounjaro/Zepbound): Lilly has offered savings programs that bring the cost down to as low as $25/month for eligible commercially insured patients. They also introduced a direct-pay option for Zepbound in 2024 at roughly $399–$549/month depending on dose — no insurance required.
• Novo Nordisk (Ozempic/Wegovy): Novo Nordisk’s savings card can reduce copays for commercially insured patients. Eligibility and terms change periodically, so check their website for current offers.

Side Effects Comparison

The side effect profiles of tirzepatide and semaglutide are similar because they share the GLP-1 mechanism. Most side effects are gastrointestinal and tend to be worst during dose escalation.

Common Side Effects (Both Medications)

• Nausea — the most frequently reported side effect. Usually peaks in the first 1–2 weeks after each dose increase and subsides.
• Diarrhea — more common in the early weeks.
• Constipation — some people get the opposite GI issue. Fiber and hydration help.
• Decreased appetite — this is the point, but it can feel extreme early on.
• Injection site reactions — mild redness or itching at the injection site. Usually minor.
• Fatigue — some people report tiredness, especially in the first few weeks.

Differences Between the Two

In the clinical trials, tirzepatide showed slightly higher rates of GI side effects — particularly nausea, diarrhea, and vomiting — compared to semaglutide, especially at the higher doses (10 mg and 15 mg). However, the difference was modest, and discontinuation rates due to side effects were similar (roughly 4–7% across both drugs).

From personal experience on tirzepatide: the nausea was real but manageable in the first week or two of each dose increase. Eating smaller meals, staying hydrated, and not eating too quickly made a significant difference. By week 3–4 at each dose, side effects were minimal.

Serious Side Effects (Rare but Important)

Both medications carry warnings for:

• Pancreatitis — rare but reported. Seek medical attention for severe, persistent abdominal pain.
• Gallbladder issues — rapid weight loss itself can increase gallstone risk.
• Thyroid C-cell tumors — seen in rodent studies. Both drugs carry a boxed warning. They are contraindicated in people with a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2.
• Hypoglycemia — risk is higher if combined with insulin or sulfonylureas.

Talk to your doctor about your full medical history before starting any GLP-1 medication. This article is for informational purposes — it is not medical advice.

Insurance Coverage Differences

Insurance coverage varies enormously depending on your plan, employer, and state. Here’s the general picture:

Mounjaro (Diabetes Indication)

Most insurance plans cover Mounjaro for type 2 diabetes since it has a diabetes-specific FDA approval. Coverage for weight loss (off-label) is inconsistent. Some plans cover it; many don’t.

Zepbound (Weight Management Indication)

Coverage is growing but still limited. Many employer plans and some state Medicaid programs now cover anti-obesity medications, but it’s far from universal. Medicare Part D does not cover weight loss drugs (though legislation to change this has been introduced in Congress).

Ozempic (Diabetes Indication)

Broad insurance coverage for type 2 diabetes. It’s been on the market since 2018, so most formularies include it. Off-label weight loss coverage varies by plan.

Wegovy (Weight Management Indication)

Better coverage than Zepbound for weight management because it’s been approved longer and has additional data (including cardiovascular benefit from the SELECT trial). More insurers have added it to their formularies since the SELECT results were published.

Tips for Getting Coverage

1. Get a prior authorization. Your prescriber may need to submit clinical documentation.
2. Check your formulary. Call your insurance company or look online to see which GLP-1s are covered and at what tier.
3. Ask about step therapy. Some plans require you to try a cheaper medication first (like metformin or naltrexone/bupropion).
4. Appeal denials. If you’re denied, ask your provider to submit a peer-to-peer review or a formal appeal with supporting clinical evidence.
5. Consider the manufacturer savings programs discussed above if your copay is still high.

How to Get GLP-1 Medications Online

Telehealth has made access to these medications much easier. Several platforms now offer GLP-1 prescriptions with online consultations. Here are the major players:

Ro (ro.co)

Ro offers both brand-name and compounded GLP-1 medications. Their platform includes an online medical evaluation, prescriber consultation, and home delivery. They’ve been one of the larger telehealth providers in this space.

Hims & Hers (hims.com / hers.com)

Hims & Hers offers compounded semaglutide and compounded tirzepatide through their weight loss program. The process includes an online consultation, and medications ship directly to your home. They also bundle in provider check-ins.

MEDVi (medvi.com)

MEDVi specializes in weight management and offers both brand-name and compounded GLP-1s. They pair medications with ongoing clinical support and body composition tracking.

What to Look for in a Telehealth Provider

• Licensed prescribers — make sure you’re seeing a licensed physician, NP, or PA.
• Compounding pharmacy quality — ask if their pharmacy is a 503B outsourcing facility (FDA-inspected) or a 503A pharmacy (state-regulated).
• Ongoing support — dose adjustments, check-ins, and lab work matter. Avoid providers that just ship medication with no follow-up.
• Transparent pricing — watch out for hidden consultation fees, mandatory subscriptions, or inflated medication costs.

Which One Should You Choose? A Decision Framework

There’s no single right answer, but here’s how to think through it:

Choose Mounjaro or Zepbound (Tirzepatide) If:

• Maximum weight loss is your priority. Tirzepatide consistently outperforms semaglutide in trials.
• You have type 2 diabetes. Tirzepatide showed excellent A1C reduction (up to 2.4% in SURPASS trials). Mounjaro has the diabetes indication.
• You can access it affordably. Whether through insurance, Lilly’s savings programs, or compounded tirzepatide.
• You’ve plateaued on semaglutide. Some people switch to tirzepatide after stalling on Ozempic/Wegovy and see renewed progress.

Choose Ozempic or Wegovy (Semaglutide) If:

• Cardiovascular protection matters. The SELECT trial demonstrated that semaglutide 2.4 mg reduced major adverse cardiovascular events (heart attack, stroke, cardiovascular death) by 20% in adults with obesity and established cardiovascular disease. Tirzepatide has not yet published equivalent cardiovascular outcome data (the SURPASS-CVOT trial is ongoing).
• Your insurance covers it. Semaglutide products, particularly Ozempic, tend to have broader formulary coverage.
• You prefer a longer track record. Semaglutide has been on the market since 2017. More long-term real-world data is available.
• Cost is a major concern and compounded semaglutide is cheaper in your area. Compounded semaglutide is sometimes available at a lower price point than compounded tirzepatide.

Mounjaro vs Zepbound — Does It Matter Which One?

Same drug. The only difference is the FDA-approved indication and how your insurance classifies it. If you have type 2 diabetes, Mounjaro may be easier to get covered. If your primary goal is weight loss and you don’t have diabetes, Zepbound is the on-label option. Your prescriber can advise on which to pursue based on your insurance situation.

Ozempic vs Wegovy — Does It Matter Which One?

Again, same drug. Wegovy goes up to 2.4 mg (vs Ozempic’s max of 2 mg) and has the weight management indication. For weight loss, Wegovy is the on-label choice. For diabetes, it’s Ozempic. In practice, many people use Ozempic off-label for weight loss because of better insurance coverage for the diabetes indication.

The Bottom Line

If you’re choosing between these medications, here’s my honest take:

Tirzepatide (Mounjaro/Zepbound) is the more effective drug for weight loss. The clinical data is clear, and the head-to-head SURMOUNT-5 trial confirmed it. If you can access it at a price you can afford, it’s the stronger option.

Semaglutide (Ozempic/Wegovy) is excellent and has the cardiovascular data edge. It’s a proven medication with years of real-world evidence. If you have heart disease risk factors, the SELECT trial data is meaningful. And if your insurance covers Ozempic or Wegovy but not Mounjaro or Zepbound, semaglutide is still a very effective choice.

Cost usually makes the decision. Most people end up on whichever medication they can actually afford and access consistently. An effective GLP-1 you can stay on is better than a theoretically superior one you can’t afford or can’t get.

Whatever you choose, pair it with strength training, adequate protein intake (aim for 0.7–1g per pound of body weight), and regular monitoring. These medications work best as part of a broader metabolic health strategy — not as a standalone solution.

I track my own progress with DEXA scans to make sure I’m losing fat and preserving lean mass. If you’re on a GLP-1, I’d strongly encourage some form of body composition tracking beyond just the scale. The scale doesn’t tell you what kind of weight you’re losing.

Frequently Asked Questions

Is Mounjaro the same as Zepbound?

Yes. Mounjaro and Zepbound both contain tirzepatide, made by Eli Lilly. The only difference is the FDA-approved indication. Mounjaro is approved for type 2 diabetes. Zepbound is approved for chronic weight management. Same molecule, same doses, same injection pens.

Can I switch from Ozempic to Mounjaro?

Yes, many people switch. Your prescriber will typically start you at a lower dose of tirzepatide (2.5 mg) even if you were on a higher dose of semaglutide, then titrate up. The two drugs have different receptor profiles, so your body needs time to adjust. Discuss timing and dosing with your provider.

How long does it take to see results?

Most people notice appetite suppression within the first 1–2 weeks. Visible weight loss typically begins within the first month. The clinical trials measured outcomes at 68–72 weeks, and weight loss was progressive throughout — meaning you keep losing weight over time as long as you continue treatment and titrate up in dose.

What happens if I stop taking GLP-1 medication?

Clinical data shows that most people regain a significant portion of lost weight after stopping GLP-1 medications. The STEP 1 extension study showed that participants regained about two-thirds of their lost weight within one year of stopping semaglutide. This is why many clinicians view these as long-term medications, similar to blood pressure or cholesterol drugs. That said, some people use GLP-1s as a bridge — losing weight, building sustainable habits, and then tapering off with close monitoring.

Are compounded GLP-1 medications safe?

Compounded medications from reputable pharmacies can be safe, but quality varies. Look for pharmacies registered as 503B outsourcing facilities, which are subject to FDA oversight and must follow current Good Manufacturing Practices (cGMP). Avoid unregulated sources, overseas pharmacies, or any provider that doesn’t require a prescription. The FDA has issued warnings about counterfeit and substandard GLP-1 products, so sourcing matters.

Do GLP-1 medications cause muscle loss?

GLP-1 medications cause weight loss, and any significant weight loss — whether from medication, surgery, or diet — involves some loss of lean mass alongside fat. Studies suggest that roughly 25–40% of weight lost on GLP-1s can be lean mass. This is why resistance training and adequate protein intake are critical. Strength training signals your body to preserve muscle. Protein provides the building blocks. If you’re on a GLP-1, these aren’t optional — they’re essential.

Last updated: February 2026. Pricing and availability may change. This article is for informational purposes only and does not constitute medical advice. Always consult a licensed healthcare provider before starting any medication.