Semaglutide vs Tirzepatide: Molecule Against Molecule
Semaglutide (semaglutide, Novo Nordisk) vs Tirzepatide (tirzepatide, Eli Lilly)
Last verified May 2026
The verdict
This is the comparison underneath every brand pairing on this site. Tirzepatide adds GIP agonism to GLP-1 and consistently produces more weight loss; semaglutide has the longer outcomes record. Both are compounded and sold across this register, and that is where the comparison stops being academic: the price gap between the two molecules in the compounded market is far narrower than the gap between either of them and a brand pen. Check the price block below.
Side-by-side comparison
| Field | Semaglutide | Tirzepatide |
|---|---|---|
| Head-to-head obesity trial (SURMOUNT-5, 72 wk) | -13.7% body weight | -20.2% body weight |
| Obesity pivotal trial (TBWL) | -14.9% / 68 wk (STEP-1) | -20.9% / 72 wk (SURMOUNT-1) |
| Type 2 diabetes head-to-head | SUSTAIN-7: -6.5 kg (sema 1.0 mg, vs dulaglutide) | SURPASS-2: -11.2 kg (tirz 15 mg) vs sema 1 mg -5.7 kg |
| Mechanism | GLP-1 receptor agonist | Dual GIP / GLP-1 receptor agonist |
| FDA-approved brands | Ozempic (T2D), Wegovy (obesity/CV), Rybelsus (oral T2D) | Mounjaro (T2D), Zepbound (obesity/OSA) |
| Cardiovascular outcome trial | SELECT: MACE -20% in obesity without diabetes | SURPASS-CVOT readout pending 2027 |
| Compounded availability (2026) | Widely available via 503A/503B pharmacies | Available but narrower supply; FDA shortage resolved Dec 2024 |
| Cash price (manufacturer direct, monthly) | $349-$499 (Wegovy NovoCare); $499 (Ozempic via NovoCare) | $349-$499 (Zepbound LillyDirect) |
What each one costs in the compounded market
Standing monthly cash prices from the 556 sellers on this register. These are compounded preparations, not the approved products compared above.
Semaglutide — semaglutide
from $79 /mo
283 sellers publish a standing price; the median is $174 a month.
Tirzepatide — tirzepatide
from $99 /mo
253 sellers publish a standing price; the median is $240 a month.
⚠ A compounded preparation is not the approved product. No agency has reviewed that specific preparation for safety, effectiveness or manufacturing quality, and the legal ground under compounding these molecules narrowed when the shortages closed. The price gap is real, and so is the difference in oversight. Every seller, with its price record.
Frequently asked questions
Which works better for weight loss, Semaglutide or Tirzepatide?
On the trial evidence, Tirzepatide. Semaglutide recorded -14.9% / 68 wk (STEP-1) and Tirzepatide -20.9% / 72 wk (SURMOUNT-1), and the head-to-head comparison put Semaglutide at -13.7% body weight against Tirzepatide at -20.2% body weight. A head-to-head is the strongest form of this evidence because both arms run under one protocol — separate trials are not directly comparable however alike they look.
Are Semaglutide and Tirzepatide the same drug?
No. Semaglutide is semaglutide and Tirzepatide is tirzepatide — different molecules, and they work differently: GLP-1 receptor agonist against Dual GIP / GLP-1 receptor agonist. Results with one do not predict results with the other.
Is Semaglutide or Tirzepatide cheaper?
On the manufacturers' own cash pricing: Semaglutide at $349-$499 (Wegovy NovoCare); $499 (Ozempic via NovoCare), Tirzepatide at $349-$499 (Zepbound LillyDirect). ⚠ That is the list-price comparison, and it is not what most people pay. What you actually pay depends on whether your plan covers it, which formulary tier it sits in, and whether you have met your deductible — and for many people the honest comparison is between an insured copay and a cash-pay compounded alternative rather than between these two figures.
Does either one have better cardiovascular evidence?
Semaglutide does. Semaglutide: SELECT: MACE -20% in obesity without diabetes. Tirzepatide: SURPASS-CVOT readout pending 2027. This matters more than it first appears — a drug with a completed outcomes trial has evidence about events that matter, not only about weight, and that is often what decides coverage.
What does a compounded version of each actually cost?
Across the 556 sellers in this register, the cheapest standing monthly cash prices we hold are semaglutide from $79 a month and tirzepatide from $99 a month. ⛔ A compounded preparation is not the approved product: no agency has reviewed that specific preparation for safety, effectiveness or manufacturing quality, and the legal ground under compounding these molecules narrowed once the shortages closed. The price gap is real and so is the difference in oversight.
Can I switch from Semaglutide to Tirzepatide?
Yes, with a prescriber. Expect to re-titrate from the bottom of the new drug's ladder rather than starting where you left off: these are different molecules and tolerance to one does not transfer to the other. Both the old drug's washout and the new drug's schedule apply.
Which one should I ask for?
That is a prescriber's call, and anyone answering it from a table is guessing. What a page like this can do is tell you what the trials measured, what the manufacturers charge, and where the evidence is still missing, so the conversation starts from the record rather than from an advertisement.
References
- 1.Aronne LJ, Horn DB, le Roux CW, et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity (SURMOUNT-5). N Engl J Med. 2025. PMID: 40353578.
- 2.Wilding JPH, Batterham RL, Calanna S, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). N Engl J Med. 2021. PMID: 33567185.
- 3.Frias JP, Davies MJ, Rosenstock J, et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2). N Engl J Med. 2021. PMID: 34170647.
- 4.Lincoff AM, Brown-Frandsen K, Colhoun HM, et al. Semaglutide and Cardiovascular Outcomes in Obesity Without Diabetes (SELECT). N Engl J Med. 2023. PMID: 37952131.
- 5.Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). N Engl J Med. 2022. PMID: 35658024.
- 6.Pratley RE, Aroda VR, Lingvay I, et al. Semaglutide versus dulaglutide once weekly in patients with type 2 diabetes (SUSTAIN 7). Lancet Diabetes Endocrinol. 2018. PMID: 29397376.
Want the underlying evidence? Read our cited, in-depth evidence review →
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See the full drug-vs-drug verdict index or provider rankings.