Wegovy vs Mounjaro: lijek za mršavljenje i lijek za dijabetes, jedan uz drugi.

Brzi odgovor

Oba lijeka djeluju na uglavnom slične načine — aktiviraju receptore crijevnih hormona koji smanjuju apetit i usporavaju pražnjenje želuca. Oba proizvode značajan gubitak težine u kliničkim ispitivanjima. Oba su tjedne injekcije koje se primjenjuju napunjenim penkalom. No regulatorno odobrenje, postupanje osiguranja i djelatna tvar sve su različiti, a te razlike određuju koji lijek zapravo možete dobiti i koliko ćete platiti.

Tablica usporedbe jedan uz drugi

Brojke u nastavku dolaze iz FDA informacija o propisivanju za svaki lijek te iz programa kliničkih ispitivanja STEP i SURMOUNT. Cijene odražavaju maloprodajne kanale u SAD-u i kanale samoplaćanja proizvođača od travnja 2026.

Najvažniji redak u toj tablici je indikacija FDA. Wegovy kaže „kronično upravljanje tjelesnom težinom". Mounjaro kaže „dijabetes tipa 2". Taj jedan redak određuje kome se svaki lijek može propisati, koji će ga osiguravajući planovi pokriti, kako izgleda papirologija za prethodno odobrenje i za što ga proizvođač smije zakonski oglašavati. Sve ostalo u usporedbi proizlazi iz te jedne regulatorne činjenice.

Ključna razlika: indikacija FDA (mršavljenje vs dijabetes)

Kada FDA odobri lijek, odobrava određenu upotrebu — zvanu indikacija — na temelju kliničkih ispitivanja koja je proizvođač predao. Ta se indikacija pojavljuje u službenim informacijama o propisivanju i jedina je upotreba koju proizvođač smije promovirati.

Wegovy je odobren u lipnju 2021. s indikacijom za kronično upravljanje tjelesnom težinom kod odraslih s indeksom tjelesne mase od 30 ili više, ili 27 ili više uz najmanje jedno stanje povezano s težinom (dijabetes tipa 2, hipertenzija, dislipidemija, apneja u snu ili kardiovaskularna bolest). Novo Nordisk predao je program kliničkih ispitivanja STEP — pet velikih ispitivanja posebno osmišljenih za mjerenje gubitka težine kao primarnog ishoda — kao potporu toj indikaciji. Godine 2024. Wegovy je dobio dodatnu indikaciju za smanjenje velikih neželjenih kardiovaskularnih događaja kod odraslih s pretilošću i utvrđenom kardiovaskularnom bolešću.

Mounjaro je odobren u svibnju 2022. s indikacijom za poboljšanje kontrole glikemije kod odraslih s dijabetesom tipa 2, kao dopuna prehrani i tjelovježbi. Eli Lilly predao je program kliničkih ispitivanja SURPASS, koji je mjerio A1C (marker šećera u krvi) kao primarni ishod. Gubitak težine bio je sekundarno opažanje u tim ispitivanjima, a ne ono za što je lijek odobren. Odobrenje Mounjara ne uključuje upravljanje tjelesnom težinom kao indikaciju.

Wegovy se suočava s drugačijom preprekom: mnogi osiguravajući planovi, Medicare Part D i većina državnih Medicaid programa povijesno su u potpunosti isključivali lijekove za mršavljenje iz pokrića. To se mijenja od 2024. — Medicare sada pokriva Wegovy za kardiovaskularnu indikaciju kod podobnih pacijenata — ali pokriće za čisto upravljanje tjelesnom težinom još je neujednačeno. Dobra vijest je da je Novo Nordisk uveo izravni kanal samoplaćanja od $499/mjesečno putem NovoCare ljekarne, koji za pacijente koji samoplaćaju u potpunosti uklanja pitanje osiguranja.

Različite djelatne tvari: semaglutid vs tirzepatid

Wegovy sadrži semaglutid. Mounjaro sadrži tirzepatid. Pripadaju preklapajućim, ali različitim skupinama lijekova.

Semaglutid (Wegovy)

Semaglutid je dugodjelujući agonist receptora glukagonu sličnog peptida-1 (GLP-1). To je sintetska verzija jednog crijevnog hormona — GLP-1 — koji tanko crijevo otpušta nakon obroka. Aktiviranjem GLP-1 receptora u mozgu, crijevima i gušterači, semaglutid smanjuje apetit, usporava pražnjenje želuca i poboljšava lučenje inzulina kao odgovor na glukozu. Molekula je konstruirana s lancem masnih kiselina koji joj omogućuje vezanje za albumin u krvi, produljujući njezino poluvrijeme na oko tjedan dana i omogućujući doziranje jednom tjedno.

Tirzepatid (Mounjaro)

Tirzepatid je dvostruki agonist — jedan peptid koji aktivira i GLP-1 receptor i GIP (glukozno-ovisni inzulinotropni polipeptid) receptor. GIP je još jedan crijevni hormon koji utječe na lučenje inzulina i skladištenje energije. Ciljanjem dvaju receptora istovremeno, tirzepatid proizvodi donekle drugačije učinke na kontrolu glukoze i tjelesnu težinu nego čisti GLP-1 agonist. U podacima iz ispitivanja, dvostruki mehanizam čini se da se prevodi u veći prosječni gubitak težine pri najvišim dozama, iako su profili nuspojava slični.

Brojke doza nisu izravno usporedive jer se odnose na različite molekule — 2.4 mg semaglutida nije isto što i 2.4 mg tirzepatida. Svaki lijek ima svoj vlastiti raspored titracije koji počinje od vrlo niske doze kako bi se smanjile gastrointestinalne nuspojave, a zatim se povećava tijekom nekoliko mjeseci do doze održavanja.

Mounjaro for weight loss: the off-label situation

A doctor in the United States can legally prescribe an approved drug for any indication they consider medically appropriate, even if that use is not on the FDA label. This is called off-label prescribing and it is common practice. Some clinicians do prescribe Mounjaro off-label for weight loss in patients without type 2 diabetes, particularly when Zepbound is in shortage or when a patient already has a Mounjaro prescription that is being covered.

The situation is essentially identical to Ozempic prescribed off-label for weight loss. The drug works whether or not the patient has diabetes — tirzepatide reduces appetite and produces weight loss regardless of glucose status — but the regulatory and reimbursement framework is built around the on-label use.

The practical problems with off-label Mounjaro for weight loss in 2026:

• Insurance denial. Almost every commercial plan requires a documented type 2 diabetes diagnosis before paying for Mounjaro. Without it, the claim is denied and the patient pays roughly $1,069/month retail.
• Manufacturer position. Eli Lilly explicitly markets Zepbound as its weight-loss product and Mounjaro as its diabetes product. The Lilly Direct self-pay program offers tirzepatide at a lower cash price under the Zepbound label, not Mounjaro.
• Supply allocation. When tirzepatide demand exceeds supply, Lilly has historically prioritized diabetes patients on Mounjaro over off-label weight loss users.
• Documentation friction. Pharmacies may flag off-label fills for additional review, and prior authorization paperwork often requires diabetes-specific lab values.

Mounjaro vs Zepbound (briefly)

This is the part that confuses almost everyone. Mounjaro and Zepbound are the same drug. They contain the identical active ingredient — tirzepatide — in identical doses, manufactured by the same company in the same facilities. Eli Lilly sells the same molecule under two brand names because each name has its own FDA approval for a different indication.

• Mounjaro — tirzepatide approved for type 2 diabetes (May 2022).
• Zepbound — tirzepatide approved for chronic weight management (November 2023).

A pharmacy cannot dispense Mounjaro when the prescription says Zepbound, or vice versa. They are listed as separate products with separate NDC codes. Insurance plans treat them as completely different medications, with different formulary tiers and prior authorization rules. The list price of Mounjaro is around $1,069/month, and Zepbound is around $1,086/month. Lilly Direct offers Zepbound at a self-pay price as low as $349-$499/month for certain doses, which is generally cheaper than retail Mounjaro for off-label use.

For a deeper comparison of semaglutide versus tirzepatide on the weight-loss-approved side, see the dedicated Wegovy vs Zepbound guide.

Effectiveness comparison

Direct head-to-head trials of semaglutide versus tirzepatide are limited, but the SURMOUNT-5 trial published in 2025 compared maximum tolerated doses of tirzepatide (Zepbound) and semaglutide (Wegovy) over 72 weeks in adults with obesity. The result: tirzepatide produced significantly more weight loss on average. For Mounjaro specifically — which has not been tested for weight loss as a primary endpoint — the available data comes from the SURPASS diabetes trials, where weight loss was a secondary outcome.

Two important caveats. First, these are averages. Individual response varies a lot — some patients on Wegovy lose 20% or more of their body weight, and some on tirzepatide lose less than 5%. Second, the Mounjaro-specific data comes from diabetes trials, where patients tend to lose less weight than non-diabetic patients on the same drug, partly because diabetes itself affects weight regulation.

The headline: tirzepatide produces more weight loss than semaglutide on average, but this matters most for the FDA-approved tirzepatide product (Zepbound), not for off-label Mounjaro use.

Side effects: Wegovy vs Mounjaro

Both drugs share the gastrointestinal side effect profile common to all GLP-1 and GIP/GLP-1 agonists. The most common complaints by far are nausea, diarrhea, vomiting, and constipation, especially during the dose escalation period in the first 16-20 weeks. Most are mild to moderate and most resolve as the body adjusts.

The percentages are not directly comparable across trials because they come from different patient populations and dosing schedules — Wegovy STEP 1 enrolled non-diabetic adults with obesity, while Mounjaro SURPASS trials enrolled patients with type 2 diabetes. In the SURMOUNT-5 head-to-head trial, both drugs caused similar overall rates of GI side effects, with tirzepatide showing slightly more nausea at the highest dose.

Both drugs carry the same boxed warning for the risk of thyroid C-cell tumors observed in rodent studies. Both are contraindicated in patients with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2 (MEN 2). For a full breakdown of semaglutide-specific side effects, see the Wegovy side effects guide.

Cost and insurance differences

This is where the FDA label difference shows up most concretely. The retail prices are similar, but the insurance pathways and self-pay options are completely different.

The bottom-line implication: if you have type 2 diabetes, Mounjaro is usually cheaper because insurance covers it. If you do not have type 2 diabetes and your goal is weight loss, Wegovy is usually cheaper because the $499 NovoCare cash-pay program is available without insurance, while Mounjaro will be billed at retail. We cover the full breakdown in the Wegovy cost guide.

Which is right for you

Use the simple decision tree below. It is not a substitute for a medical evaluation, but it covers the most common situations.

The clearest cases are the bookends: pure type 2 diabetes management points to Mounjaro, pure weight management without diabetes points to Wegovy or Zepbound. The middle case — adults with both diabetes and obesity — is the one most worth discussing with a clinician, because all three drugs may be on the table and the right answer depends on insurance, prior medications, A1C, and personal preference.

Want to compare Wegovy against more options? See the all-GLP-1s comparison page for a side-by-side of Wegovy, Zepbound, Mounjaro, Ozempic, and Saxenda.