Wegovy vs Zepbound: Weight Loss, Side Effects and Cost

Zepbound produces more weight loss than Wegovy on average. That's the one-line answer, and it comes from a real head-to-head trial, not a guess. Price is where it gets interesting: at the higher doses, Zepbound can cost twice as much as Wegovy if you pay cash.

I took semaglutide, not tirzepatide, so I have no horse in this race. Here is how the two compare on the four things people actually ask me about.

What's the difference between Wegovy and Zepbound?

They are two different molecules from two different companies. Wegovy is semaglutide (Novo Nordisk), and it acts on one gut-hormone receptor, GLP-1. Zepbound is tirzepatide (Eli Lilly), and it acts on two: GLP-1 and GIP.

Both are once-weekly shots for chronic weight management, and both start low and step up every four weeks. Their milligram numbers are not comparable, though. A 5 mg dose of one is not the same as 5 mg of the other, which matters if you ever switch.

Which one causes more weight loss?

Zepbound, by about six and a half percentage points. SURMOUNT-5 randomized 751 adults with obesity (no diabetes) to the highest dose each person could tolerate of either drug for 72 weeks¹. Average weight loss was 20.2% on tirzepatide and 13.7% on semaglutide, and waist size dropped 18.4 cm versus 13.0 cm¹.

Two caveats are worth knowing. The trial was open-label (everyone knew which drug they got), and Lilly, Zepbound's maker, funded it¹. Neither changes the direction of the result, which matches the separate trials: semaglutide 2.4 mg averaged about 14.9% in STEP 1².

Remember that these are averages. Some people lose more on Wegovy than the average Zepbound user, and the drug you can stay on for a year beats the one you quit in month three.

Does Wegovy HD close the gap?

Partly. Wegovy's label now allows a 7.2 mg maintenance dose (sold as Wegovy HD) for adults who have tolerated 2.4 mg for at least four weeks⁴. In the STEP UP trial, 7.2 mg averaged 18.7% weight loss at 72 weeks, versus 15.6% on 2.4 mg³.

That gets semaglutide closer to tirzepatide's number, but it's a different trial with different people. No study has put Wegovy 7.2 mg against Zepbound directly, so treat "about the same" as unproven.

Which one has worse side effects?

They share the same family of side effects: nausea, diarrhea, vomiting and constipation, mostly while the dose is climbing. In SURMOUNT-5, stomach symptoms were the most common problem with both drugs, and most were mild to moderate¹.

Each drug's FDA label reports its own placebo-controlled trials. Read the table below as "how often, versus placebo", not as a head-to-head scorecard, because the trials differ.

Sources: Wegovy and Zepbound FDA labels^4,5, read October 2026.

The practical lesson is the same for both. How slowly you climb matters more than which brand you're on. If a step-up is rough, ask your prescriber about staying at your current dose an extra month. My own nausea was worst in the first week after each increase and faded by the third. For what helps in the meantime, see semaglutide nausea remedies.

Both labels carry the same boxed warning about thyroid C-cell tumors, plus cautions on pancreatitis and gallbladder disease. Those are class warnings, not a difference between the two.

What does each cost without insurance?

Both makers now sell directly to cash-paying patients, and the price shapes are very different. Wegovy charges one price across its whole standard ladder. Zepbound's price climbs with the dose.

Year one follows the label's step-ups to 2.4 mg or 15 mg. NovoCare's $199 intro covers a new patient's first two monthly fills and runs through December 31, 2026; after that it's $349 at every dose from 0.25 to 2.4 mg. Lilly's prices are per four-week vial or KwikPen fill⁶. Both read on the makers' own pricing pages, October 4, 2026.*

If your prescriber settles you on Zepbound 5 mg, the gap shrinks: a year runs about $5,087. The government's TrumpRx site also lists both brands at headline "from" prices ($199 for the Wegovy pen, $299 for Zepbound), so compare the dose you'll actually be on, not the opening number.

Neither price includes a prescriber. You still need a prescription, either from your own doctor or a telehealth program. NovoCare's own pharmacy fills Wegovy at the self-pay price. For more on stretching the Wegovy side, see Wegovy cost and savings, and plug your own numbers into the Wegovy cost calculator.

Why do people switch from Wegovy to Zepbound?

Usually for one of three reasons: weight loss stalled on Wegovy, side effects were hard to live with, or insurance covered one but not the other. A smaller group switches the other way, because Wegovy's flat price is easier to budget or because their doctor wants semaglutide's proven heart-outcome data.

Whatever the reason, the doses don't convert one to one. A switch is re-titrated by your prescriber, often from a low step. Switching from Zepbound to Wegovy (and back) walks through how that usually goes.

Is compounded semaglutide or tirzepatide cheaper?

Usually, yes, but it's not the same product. Compounded versions are not FDA-approved, and the legal room for mass compounding narrowed sharply after both shortages ended. Before you weigh a lower monthly price, read compounded semaglutide vs Wegovy for what you give up.

If you've already decided on the molecule, the deeper breakdown of efficacy and heart data lives in semaglutide vs tirzepatide. For programs that prescribe each, see the semaglutide provider guide and the tirzepatide provider guide, where the order is commercial and every partner is tagged.