Key takeaways What are semaglutide and tirzepatide? Quick answer: Semaglutide and tirzepatide are prescription medications that mimic gut hormones to reduce appetite and slow digestion. Both are FDA-approved for type 2 diabetes and weight management, sold under brand names Ozempic, Wegovy, Rybelsus (semaglutide) and Mounjaro, Zepbound (tirzepatide). What’s the difference between semaglutide and tirzepatide? Quick […]
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Quick answer: Semaglutide and tirzepatide are prescription medications that mimic gut hormones to reduce appetite and slow digestion.
Both are FDA-approved for type 2 diabetes and weight management, sold under brand names Ozempic, Wegovy, Rybelsus (semaglutide) and Mounjaro, Zepbound (tirzepatide).
Quick answer: Semaglutide activates one hormone receptor (GLP-1). Tirzepatide activates two (GLP-1 and GIP). That second receptor is part of why tirzepatide tends to produce more weight loss in studies.
Both semaglutide and tirzepatide copy hormones your body already makes in response to food. They slow how fast your stomach empties, tell your brain you’re full sooner, and quiet the background hunger most people feel between meals.
Semaglutide came first. The FDA approved it for type 2 diabetes in 2017 (as Ozempic) and for weight loss in 2021 (as Wegovy). Novo Nordisk makes both. Tirzepatide came later, with FDA approval for type 2 diabetes in 2022 (Mounjaro) and weight loss in 2023 (Zepbound). Eli Lilly makes both.
Tirzepatide hits a second receptor called GIP, which seems to amplify the effect on appetite and fat storage. Researchers think this is why tirzepatide tends to outperform semaglutide on weight loss in clinical trials.
Semaglutide vs tirzepatide at a glance: Tirzepatide produces more weight loss (about 20% versus 14% over 72 weeks). Semaglutide has more proven uses, including heart disease, kidney disease, and liver disease. Both cause similar side effects. Cost is comparable at list price, but insurance coverage and manufacturer programs can shift the math significantly.
| Semaglutide | Tirzepatide | |
|---|---|---|
| Brand names | Ozempic, Wegovy, Rybelsus | Mounjaro, Zepbound |
| Manufacturer | Novo Nordisk | Eli Lilly |
| How it works | GLP-1 receptor agonist | Dual GLP-1 and GIP receptor agonist |
| FDA approved for | Type 2 diabetes, weight loss, cardiovascular risk reduction, kidney disease, MASH (liver disease) | Type 2 diabetes, weight loss, obstructive sleep apnea |
| Forms available | Weekly injection, daily pill | Weekly injection only |
| Average weight loss (head-to-head, 72 weeks) | 13.7% | 20.2% |
| Cardiovascular benefit proven? | Yes (SELECT, SUSTAIN-6 trials) | Studies ongoing |
| List price (monthly) | $1,028 (Ozempic), $1,349 (Wegovy) | $1,112 (Mounjaro), $1,086 (Zepbound) |
Quick answer: Tirzepatide produces more weight loss on average, but semaglutide still works well for most.
The most direct comparison we have is from SURMOUNT-5, a 72-week trial published in the New England Journal of Medicine in 2025. It compared semaglutide and tirzepatide in 751 adults with obesity but without type 2 diabetes. People on tirzepatide lost an average of 20.2% of their body weight. People on semaglutide lost 13.7%.
A 2025 meta-analysis in the Journal of Clinical Medicine Research, which combined seven studies, found similar results. Tirzepatide produced about four more percentage points of weight loss than semaglutide, and the gap got bigger at higher doses and longer treatment durations.
That said, the 7.2 mg high-dose version of semaglutide (Wegovy HD), approved by the FDA in March 2026, produces about 21% weight loss in trials, which approaches tirzepatide’s 22.5% at the 15 mg dose. So at the highest doses, the gap narrows.
If your only goal is the maximum possible weight loss, tirzepatide has the edge. If you’ve already lost a meaningful amount on semaglutide and you’re happy with it, there’s no reason to switch.
Tirzepatide leads to greater average weight loss than semaglutide in clinical trials. If it’s the right fit for you, Astra offers compounded tirzepatide from a licensed 503A pharmacy at $118/month for the annual plan.
See if tirzepatide is right for you → Clinician-reviewed. No hidden fees.Quick answer: Both work, but tirzepatide lowers A1C more in head-to-head studies. Semaglutide has stronger cardiovascular and kidney evidence.
In the SURPASS-2 trial, tirzepatide lowered A1C by 2.0% to 2.5%. Semaglutide lowered it by about 1% to 2%. People on tirzepatide also lost more weight (17 to 25 pounds versus 13 pounds).
But there’s a caveat: SURPASS-2 used semaglutide at 1 mg. The FDA approved a 2 mg dose in 2022, which Novo Nordisk says closes some of that gap. A 2026 real-world study from Novo Nordisk of 64,000 adults with type 2 diabetes found that escalating from semaglutide 1 mg to 2 mg produced similar A1C results to switching to tirzepatide, and actually edged out tirzepatide on weight loss in that specific scenario.
While this update comes from manufacturer-funded studies, the finding does suggest dose matters.
Semaglutide has FDA approval for cardiovascular risk reduction in people with heart disease (based on the SUSTAIN-6 and SELECT trials) and for slowing kidney disease progression.
Tirzepatide doesn’t have FDA approval for cardiovascular risk reduction yet. The SURPASS-CVOT trial, which compares tirzepatide head-to-head against dulaglutide (a GLP-1 with established cardiovascular benefit) in 13,299 people with type 2 diabetes and existing cardiovascular disease, is running now.
Results are expected to determine whether tirzepatide gets the same cardiovascular protection labeling that semaglutide already has.
Quick answer: Semaglutide and tirzepatide cause similar side effects, mostly stomach-related. Tirzepatide has slightly higher rates of nausea and diarrhea at the highest doses, but most people tolerate either drug.
The most common side effects for both are nausea, diarrhea, vomiting, constipation, and stomach pain. These usually show up in the first few weeks or when your dose goes up, and they tend to fade as your body adjusts.
In SURPASS-2, gastrointestinal side effects were similar between the two. Serious side effects occurred slightly more often in the tirzepatide group (5.3% to 7%) than the semaglutide group (2.8%).
Both drugs carry the same FDA boxed warning for a possible risk of thyroid C-cell tumors. This came from animal studies, and it’s not known whether the risk applies to humans. Don’t take either drug if you or your family have a history of medullary thyroid carcinoma or MEN 2 syndrome.
A few side effects you should know about:
Quick answer: A doctor might choose semaglutide over tirzepatide if you have heart disease, kidney disease, or liver disease (specifically MASH), or if you prefer a daily pill over a weekly injection.
Semaglutide has more FDA-approved uses than tirzepatide:
If any of those apply to you, your prescriber may lean toward semaglutide for the additional benefits beyond weight loss or blood sugar control.
Semaglutide is also available as a daily pill. Rybelsus is the oral version for type 2 diabetes (7 mg or 14 mg doses), and the Wegovy pill (25 mg once daily) was approved by the FDA in December 2025 for weight management.
The Wegovy pill produced about 13.6% mean weight loss in the OASIS 4 trial, which is similar to what injectable Wegovy delivers. It’s also approved to reduce the risk of heart attack and stroke in adults with heart disease.
Tirzepatide is only available as a weekly injection. If the idea of injecting yourself is the main thing keeping you from starting GLP-1 treatment, the Wegovy pill is a real option that didn’t exist a year ago.
That said, tirzepatide has its own unique approval: it’s the only FDA-approved drug for moderate to severe obstructive sleep apnea in adults with obesity. If you have sleep apnea along with obesity, your prescriber might lean toward Zepbound.
Quick answer: List prices are similar ($1,028 to $1,349 per month for semaglutide, $1,086 to $1,112 for tirzepatide). What you actually pay depends on insurance, manufacturer programs, and whether you use compounded versions.
Brand-name pricing:
Compounded versions (made by 503A pharmacies) typically run $68 to $300 per month for semaglutide and $118 to $400 for tirzepatide depending on your subscription plan. They’re not FDA-approved as finished products, and the rules around them tightened in 2026.
A licensed clinician reviews your medical history and helps you decide.
Quick answer: Yes, but the switch requires a prescriber’s involvement to match doses, time the transition, and watch for side effects in the first few weeks.
People switch for a few reasons: their weight loss plateaued on semaglutide, they’re hoping tirzepatide will produce faster results, or they want to try the dual-receptor mechanism.
Tirzepatide doses don’t translate 1:1 from semaglutide doses, and starting at the wrong dose can mean either a wave of side effects or a wasted month at a dose that’s too low. A typical approach is to stop semaglutide, wait one full week (one dosing cycle), then start tirzepatide at 2.5 mg weekly.
Some prescribers move faster if you’ve been on a higher semaglutide dose for a while. Expect some side effects in the first few weeks even if you didn’t have them on semaglutide. The two drugs feel different, and tirzepatide’s dual mechanism can produce nausea or fullness patterns your body isn’t used to.
Quick answer: Compounded semaglutide and tirzepatide cost less than the brand-name versions and use the same active ingredients, but they are not FDA-approved. Quality depends on the pharmacy.
Compounded GLP-1 medications became widely available during the 2022-2024 Ozempic and Mounjaro shortages. The FDA declared the shortages resolved in early 2025 and tightened the rules in 2026. As of 2026, 503A pharmacies can still legally compound semaglutide and tirzepatide for individual patients when a prescriber documents clinical need.
A few things to know if you’re considering compounded:
For more on the regulatory side and how to evaluate a compounded provider, see our guides on compounded GLP-1 medications and 503A compounding.
Both semaglutide and tirzepatide work. Tirzepatide tends to produce more weight loss in studies, but semaglutide has more proven uses across heart, kidney, and liver health.
For more on what GLP-1 treatment actually looks like in practice, see our guide on what to expect in your first month on compounded GLP-1.
If you’re considering GLP-1 treatment, Astra (try-astra.com) prescribes through licensed clinicians at Wasef Health, PC. Compounded prescriptions are filled by VialsRx, a US-licensed 503A pharmacy. Compounded semaglutide starts at $68 per month, compounded tirzepatide starts at $166 per month, and microdose protocols start at $89 per month on a 6-month plan for microdose semaglutide and $109 on a 6-month plan for microdose tirzepatide.
Brand-name Ozempic, Wegovy, and Zepbound are also available through Astra’s program.
Astra offers both semaglutide and tirzepatide. A licensed clinician at Wasef Health, PC reviews your case and recommends the option that fits your goals, tolerance, and budget.
Start your health profile Takes about 5 minutes.Tirzepatide produces more weight loss and lowers A1C more than Ozempic in head-to-head studies. In SURPASS-2, tirzepatide led to 17-25 pounds of weight loss compared to 13 pounds with Ozempic over 40 weeks. But the study used Ozempic 1 mg, not the newer 2 mg dose. At equivalent maintenance doses, the gap is smaller than the original trial suggested.
Tirzepatide produces more weight loss on average, but if semaglutide is working for you or your insurance covers it and not tirzepatide, switching may not be worth the cost or the side-effect reset. If you’ve plateaued on semaglutide or you’re paying cash either way, tirzepatide is reasonable to consider.
Compounded tirzepatide is cheaper because compounding pharmacies skip the FDA approval process, the brand-name marketing costs, and the patent protections that drive up brand pricing. They’re not generics (no FDA-approved generic GLP-1 exists), and the savings come with quality and oversight tradeoffs.
Yes. Your prescriber will help you transition by waiting one full week after your last semaglutide dose, then starting tirzepatide at 2.5 mg weekly. Some people titrate up faster depending on what dose they were on. Expect some side effects in the first few weeks even if semaglutide was easy.
Both cause similar stomach side effects (nausea, diarrhea, vomiting, constipation) and they’re worse in the first few weeks or when your dose goes up. Tirzepatide may produce slightly more nausea at the highest 15 mg dose, but for most people, the side effect profiles are comparable.
No, but the FDA is restricting it. A proposed FDA rule from April 2026 would remove semaglutide, tirzepatide, and liraglutide from the 503B bulks list, which would mostly end large-scale bulk compounding by outsourcing facilities. 503A pharmacies can still compound for individual patients with documented clinical need.
Most people regain some weight after stopping either drug. In the STEP 1 trial extension, people who stopped semaglutide regained about two-thirds of their lost weight within a year. The SURMOUNT-4 trial showed similar results with tirzepatide. Obesity is treated as a chronic condition, which is why both drugs are often used long-term rather than as short-term interventions.
No. Don’t take semaglutide and tirzepatide at the same time, or any combination of GLP-1 medications. They work on the same receptors, and combining them raises the risk of severe side effects without any added benefit.
Tirzepatide (Zepbound) is the only FDA-approved drug for moderate to severe obstructive sleep apnea in adults with obesity. It got the approval in December 2024. Semaglutide is not approved for sleep apnea, although weight loss from either drug can improve sleep apnea symptoms.
This article is for educational purposes only and does not constitute medical advice. Consult a licensed physician regarding any medical condition or treatment.