This is Part 1 of our 8-part GLP-1 Weight Loss Series. Over the next few weeks we’ll cover how to get a prescription online, what it really costs in 2026, side effects, eligibility, and more. Up next: how to get a GLP-1 prescribed online — legally and safely. Today: the question almost everyone starts with — semaglutide or tirzepatide?
Semaglutide vs. Tirzepatide: The Short Answer
If you’re choosing between the two big weight-loss medications, here’s the honest version: in the first head-to-head clinical trial, tirzepatide (Zepbound) produced more weight loss than semaglutide (Wegovy) — about 20% of body weight versus about 14% over 72 weeks. But “more” isn’t automatically “better for you.” The right GLP-1 depends on your health history, how your body tolerates side effects, your insurance, and your budget. Let’s break down exactly how they compare so you can have a smart conversation with your doctor.
The 30-second version
- Tirzepatide (Zepbound/Mounjaro) works on two gut hormones; semaglutide (Wegovy/Ozempic) works on one.
- Tirzepatide wins on average weight loss (~20% vs ~14% head-to-head), but both are highly effective.
- Side effects are similar — semaglutide leans toward nausea, tirzepatide toward diarrhea — and usually fade after the dose-increase phase.
- Only FDA-approved versions are reliably tested for dose and safety. Compounded “knockoff” GLP-1s are being phased out by the FDA in 2025–2026.
- The best choice is individual — and it’s a decision to make with a board-certified doctor.
How the Two Medications Compare
Both belong to a class of drugs called GLP-1 receptor agonists — they mimic hormones your gut releases after eating, which slows digestion, steadies blood sugar, and quiets appetite. The headline difference: tirzepatide adds a second hormone pathway (GIP), which is why it tends to deliver more weight loss. Here’s the side-by-side.
| Semaglutide | Tirzepatide | |
|---|---|---|
| Brand names | Wegovy (weight loss), Ozempic (diabetes) | Zepbound (weight loss), Mounjaro (diabetes) |
| How it works | Single hormone (GLP-1) | Dual hormone (GLP-1 + GIP) |
| Avg. weight loss* | ~14–15% of body weight | ~20–21% of body weight |
| How it’s taken | Weekly injection (oral version now available for some uses) | Weekly injection |
| Most common side effects | Nausea, constipation | Diarrhea, nausea (often milder) |
*Average results from FDA registration trials (STEP-1, SURMOUNT-1) and the SURMOUNT-5 head-to-head trial, 2021–2025. Individual results vary.
Which One Causes More Weight Loss?
Tirzepatide produces more weight loss on average. The clearest evidence came in 2025 from SURMOUNT-5, the first trial to put the two drugs against each other directly.
Head-to-head weight loss — by the numbers
- ~20.2% average body-weight loss on tirzepatide over 72 weeks.
- ~13.7% average body-weight loss on semaglutide over the same period.
- That tracks with their individual trials: semaglutide averaged ~15% in STEP-1; tirzepatide reached up to ~21% at its highest dose in SURMOUNT-1.
Source: SURMOUNT-5 head-to-head trial, 72 weeks, published 2025.
Here’s the important nuance: those are averages. Plenty of people lose substantial weight on semaglutide, and a smaller number respond better to it than to tirzepatide. More weight loss on paper also isn’t the only goal — a medication you can actually tolerate and stay on consistently will almost always beat a “stronger” one you quit after a month. That’s why this decision belongs with a doctor who knows your full picture, not a chart.
How Do the Side Effects Compare?
The side effects are similar because the drugs work in similar ways — mostly digestive, and mostly during the first few weeks as your dose increases. The pattern differs slightly. Semaglutide tends to cause more nausea and constipation. Tirzepatide more often causes diarrhea, but tends to cause less nausea than you might expect for how strong it is.
- Most common (both): nausea, diarrhea or constipation, vomiting, reduced appetite, fatigue, burping
- Usually temporary: most noticeable while stepping up to your target dose, and typically ease at a stable maintenance dose
- How doctors reduce them: a slow, gradual dose increase, smaller and lower-fat meals, and staying hydrated
When to call your doctor: Seek care for severe or persistent abdominal pain (especially pain radiating to your back — a possible sign of pancreatitis), persistent vomiting, signs of a gallbladder problem, or any allergic reaction. GLP-1 medications are not appropriate for people with a personal or family history of medullary thyroid cancer or MEN2.
What About Cost?
Both carry high list prices — often $1,000–$1,600 per month without coverage — but very few people pay that today. Manufacturer direct-pay programs, pharmacy discounts, and new federal pricing options have pushed real-world cash prices well below list. As of 2026, common out-of-pocket ranges look like this:
| Path | Typical monthly cost (2026) |
|---|---|
| Covered by insurance | $0–$50 copay (when your plan covers weight-loss meds) |
| Manufacturer cash-pay / direct programs | ~$349–$499 / month depending on drug and dose |
| List price (no coverage, no program) | ~$1,000–$1,600 / month |
Prices change frequently — confirm current pricing and your coverage with your provider and pharmacy. A Medicare GLP-1 access program offering eligible members roughly $50/month is slated to begin July 1, 2026. We cover this in depth in Part 3 of this series.
A Word on “Compounded” GLP-1s
During the 2022–2024 shortages, many websites sold cheaper compounded semaglutide and tirzepatide — versions mixed by pharmacies rather than the FDA-approved branded products. That window is closing. After the FDA declared the shortages resolved, the legal allowance for mass-compounding these drugs ended in 2025, and in 2026 the FDA proposed removing them from the compounding list permanently. Several large telehealth companies have already stopped selling compounded GLP-1s.
Why this matters for you: FDA-approved Wegovy, Ozempic, Zepbound, and Mounjaro are tested for consistent dosing, purity, and safety. WeHealth’s board-certified Obesity Medicine doctors prescribe FDA-approved GLP-1 medications — not compounded substitutes — so you know exactly what you’re putting in your body.
So Which GLP-1 Is Right for You?
If maximum weight loss is the single priority and you tolerate it well, the data points toward tirzepatide. If you have a specific reason to start with semaglutide — your insurance covers it, you respond well to it, your doctor prefers it for your health history, or you want an option with an oral form — it remains a highly effective choice that has helped millions of people. The honest answer is that “better” is the one that fits your body, budget, and life, and that you can stay on consistently. A doctor will weigh:
- Your weight-loss goal and how much you have to lose
- Other health conditions — type 2 diabetes, heart disease, digestive issues
- Your side-effect tolerance and history with similar medications
- Insurance and budget — what’s actually covered for you
- Whether you’ll have ongoing support — coaching, labs, and dose adjustments keep results going
Tip: GLP-1 medications work best alongside nutrition and lifestyle support — not instead of it. The patients who keep weight off pair the medication with sustainable habits. WeHealth includes nutrition coaching and doctor-reviewed vitals tracking with its medical weight-loss program.
How to Start With WeHealth
WeHealth connects you with board-certified Obesity Medicine doctors who can evaluate whether an FDA-approved GLP-1 is right for you — entirely online, with most insurance accepted. No waiting room, no months-long wait for an appointment.
- Free evaluation — complete a medical intake; your doctor reviews your history and labs.
- Get prescribed — if appropriate, an FDA-approved GLP-1 is sent to your pharmacy or shipped to your door.
- Ongoing care — nutrition coaching, lab work, and dose adjustments are built in, with your vitals tracked in the app.
Learn more about GLP-1 medications for weight loss and diabetes, or download the WeHealth app to start your evaluation today.
Frequently Asked Questions
Is tirzepatide just a stronger version of semaglutide?
Not exactly — they’re different molecules. Semaglutide activates one gut-hormone receptor (GLP-1), while tirzepatide activates two (GLP-1 and GIP). That dual action is the main reason tirzepatide tends to produce more weight loss on average. But the right choice still depends on your individual health, tolerance, and coverage.
Can I switch from semaglutide to tirzepatide?
Many people do, usually because of side effects, cost or coverage changes, or a weight-loss plateau. Switching should always be guided by your doctor, who will set the right starting dose on the new medication and adjust gradually to limit side effects. Never switch on your own.
Will I regain the weight if I stop?
Some regain is common after stopping any GLP-1, because the medication’s appetite effects end when you stop taking it. That’s why doctors treat obesity as a long-term condition and pair medication with lasting nutrition and lifestyle changes. A maintenance plan — sometimes at a lower dose — helps protect your results. (More on this in Part 7 of this series.)
Do I need diabetes to take these for weight loss?
No. Wegovy (semaglutide) and Zepbound (tirzepatide) are FDA-approved specifically for chronic weight management in adults who meet certain BMI criteria, with or without diabetes. Ozempic and Mounjaro are approved for type 2 diabetes. A doctor confirms which product and indication fit your situation.
Can I get a GLP-1 prescribed online?
Yes. WeHealth’s board-certified Obesity Medicine doctors can evaluate you online and, if appropriate, prescribe an FDA-approved GLP-1 — sent to your pharmacy or shipped to your door. Most insurance is accepted, and labs, coaching, and dose adjustments are included in the program.
Are compounded GLP-1s safe and legal?
The FDA’s allowance for mass-compounding semaglutide and tirzepatide ended in 2025 after the drug shortages were resolved, and the FDA proposed a permanent ban in 2026. FDA-approved branded products are tested for consistent dosing and purity. WeHealth prescribes FDA-approved GLP-1 medications only.
Coming Up in Part 2
Next: How to Get a GLP-1 Prescription Online — Legally and Safely. We’ll walk through exactly how an online evaluation works, what makes a telehealth GLP-1 prescription legitimate, and the red flags to avoid now that compounded versions are being phased out.
Ready to See If a GLP-1 Is Right for You?
Choosing a weight-loss medication is a real medical decision — and you don’t have to make it alone. A board-certified doctor can look at your whole health picture and help you pick the option that’s safest and most effective for you. Download the WeHealth app to start your free evaluation, or explore our online medical weight-loss program. Most insurance accepted — no waiting room.
Medical Disclaimer: This article is for informational purposes only and is not a substitute for medical advice, diagnosis, or treatment from a qualified healthcare provider. GLP-1 medications are prescription drugs with risks and contraindications. Pricing and FDA policy are subject to change; confirm current details with your provider. Always talk to a doctor about whether a GLP-1 is right for you, and never start, stop, or switch a prescription on your own. Written by the WeHealth Medical Team. Medically reviewed by [Reviewer Name], MD, Board-Certified in Obesity Medicine. Last updated: June 30, 2026.