Yes. Zepbound and Mounjaro are the same molecule, tirzepatide. Both come from Eli Lilly. Both run the same weekly ladder, 2.5 mg up to 15 mg [4] [5]. What differs is the label and the price. Mounjaro is approved for type 2 diabetes. Zepbound is approved for weight and for sleep apnea with obesity. Lilly lists Mounjaro at “$1,112.16 per fill” and Zepbound at “$499 - $1,086.37 per fill” [6] [7].
The question matters because the two names are billed differently. A plan may cover one and refuse the other. The diagnosis on the prescription decides which label applies. The broader picture of who pays is in what decides your bill. The cash market is in what a GLP-1 costs per month.
What the two labels say
Mounjaro’s label has two uses. It improves blood sugar in type 2 diabetes. It also lowers the risk of heart attack, stroke and cardiovascular death in high-risk type 2 diabetes [5]. It is also approved for children 10 and older with type 2 diabetes. Their maximum is 10 mg [5].
Zepbound’s label also has two uses. It reduces excess body weight in adults with obesity. It also covers adults with overweight and at least one weight-related condition. And it treats moderate to severe obstructive sleep apnea in adults with obesity [4]. Neither use requires diabetes.
The dosing is the same in the steps that matter. Both start at 2.5 mg a week. Both climb in 2.5 mg steps after at least four weeks. Both stop at 15 mg [4] [5]. Zepbound names 5, 10 or 15 mg as maintenance doses for weight. For sleep apnea it names 10 or 15 mg [4].
Two trial programs, one molecule
Each label rests on its own trials. Zepbound’s weight label leans on SURMOUNT-1. That trial enrolled 2,539 adults without diabetes for 72 weeks [1]. Weight fell 15.0% on 5 mg. It fell 19.5% on 10 mg and 20.9% on 15 mg. Placebo lost 3.1% [1].
Mounjaro’s program measured blood sugar first. SURPASS-2 randomized 1,879 people with type 2 diabetes for 40 weeks [2]. HbA1c fell 2.01 to 2.30 percentage points on tirzepatide. It fell 1.86 points on semaglutide 1 mg [2]. Weight loss beat semaglutide by 1.9 kg to 5.5 kg, depending on dose [2].
One more trial links the two. SURMOUNT-2 gave tirzepatide for weight to 938 adults who had type 2 diabetes [3]. Weight fell 12.8% on 10 mg and 14.7% on 15 mg. Placebo lost 3.2% [3]. That is lower than in SURMOUNT-1. The people differed, so this is a contrast between trials, not a head-to-head result. It still says the same molecule does not produce the same number in everyone. The dose side of that is in which Zepbound dose works best.
What the list prices say, and what they leave out
Lilly publishes both list prices on its own pricing pages. Mounjaro: “The list price of Mounjaro is $1,112.16 per fill” [7]. Zepbound: “The list price of Zepbound is $499 - $1,086.37 per fill” [6]. Lilly defines list price as its sale price to wholesalers [6]. It is not a pharmacy counter price.
The bigger difference is the cash channel. Zepbound has a direct-to-patient price by dose. Lilly prints it as “$299, $399, $499, $699, $699 and $699 respectively” for 2.5 mg through 15 mg [6]. That covers a four-vial box or a KwikPen. Lilly’s own pharmacy lists the KwikPen lower from 7.5 mg up. It reads “Starting at $449/month” “when you refill within 45 days” [9]. Lilly’s Mounjaro price page names self-pay options. It prints no self-pay figure [7].
The savings cards differ too. Zepbound’s card can bring a covered fill to “as low as $25”. It says “Governmental beneficiaries excluded” [6]. Mounjaro’s card has a second tier for commercial plans that do not cover it. That tier reads “pay as low as $499 for a 1-month prescription fill” [8]. A card is not a price. Each tier carries caps and terms.
So the cash buyer’s question is narrower than the brand name suggests. It is tirzepatide at a stated dose, from a named channel, per 28 days. That is how this desk compares it against compounded tirzepatide and against semaglutide. The paired gap is in the tirzepatide premium at the same seller. Whether the premium buys anything is in whether tirzepatide is worth the extra cost.
Where the label changes the bill
A diagnosis of type 2 diabetes points a prescription at Mounjaro. Weight alone points it at Zepbound. A plan’s formulary can treat the two differently. The price of the same molecule then moves with the label. The same split runs through semaglutide, where Ozempic and Wegovy divide the same way. That pair is laid out in whether Wegovy is the same as Ozempic.
Brand results also get quoted without the label behind them. In one large cohort, Zepbound users reached a 15% loss more often than Mounjaro users. Dose and patient mix explain most of that, as the brand confound shows. Compounded tirzepatide is neither Zepbound nor Mounjaro. It is not FDA-approved and carries neither label.