Liraglutide vs Tirzepatide: Saxenda vs Zepbound Compared (2026)

Written by Nataliia Bondarchuk. Updated November 4, 2026.

No trial has compared liraglutide and tirzepatide head to head, but in their main weight-loss trials tirzepatide produced roughly two to three times more weight loss: 15% to 20.9% of body weight over 72 weeks in SURMOUNT-1, against about 8.4 kg (roughly 8%) over 56 weeks for liraglutide 3 mg in SCALE, and it is injected once a week rather than once a day. Liraglutide (Saxenda for weight, Victoza for type 2 diabetes) is now available as a cheaper generic; tirzepatide (Zepbound for weight, Mounjaro for diabetes) is not. And Novo Nordisk says it is discontinuing brand Saxenda in the US, with last shipments to wholesalers planned for late January 2027. This guide compares weight loss, blood sugar, heart data, dosing, side effects, teen use and cost.

Both drugs copy gut hormones released after eating, which boost insulin when blood sugar is high, slow stomach emptying and reduce appetite. Liraglutide activates the receptor for one hormone, GLP-1 (glucagon-like peptide-1). Tirzepatide activates the receptors for both GLP-1 and GIP (glucose-dependent insulinotropic polypeptide). How this plays out in the body is explained in how Zepbound works.

Liraglutide has a half-life of about 13 hours, so it is injected daily; tirzepatide's is about five days, so it is weekly. The differences between the two tirzepatide brands are covered in Mounjaro vs Zepbound.

On the available evidence, tirzepatide causes considerably more weight loss, but that conclusion rests on separate trials. In SCALE Obesity and Prediabetes, 3,731 adults took liraglutide 3 mg or a placebo for 56 weeks. The liraglutide group lost an average of 8.4 kg, against 2.8 kg on placebo; 63.2% lost at least 5% of their weight and 33.1% lost at least 10%. In SURMOUNT-1, 2,539 adults without diabetes took tirzepatide 5, 10 or 15 mg or a placebo for 72 weeks. Average weight loss was 15.0%, 19.5% and 20.9%, against 3.1% on placebo, and more than half of people on the two higher doses lost at least 20%.

We found no randomized trial that compares the two drugs directly. A network meta-analysis in the journal Obesity, which compares drugs indirectly through their trials against placebo, ranked high-dose tirzepatide first and liraglutide 3 mg last among the drugs studied. Because SURMOUNT-1 lasted longer and enrolled different people, treat the gap as a rough guide. How results build over time on tirzepatide is covered in how long it takes for Zepbound to work.

A1C is a blood test that reflects average blood sugar over about three months. For people with type 2 diabetes, the two drugs were again tested in different trials against different comparisons. In LEAD-3 Mono, liraglutide lowered A1C by 0.84 percentage points at 1.2 mg and 1.14 points at 1.8 mg over 52 weeks, against 0.51 points on the older pill glimepiride. In SURPASS-2, tirzepatide lowered A1C by 2.01 to 2.30 points over 40 weeks, against 1.86 points on semaglutide 1 mg (the drug in Ozempic). The people studied differed, so these numbers cannot be subtracted from one another, though SURPASS-2 did show tirzepatide beating semaglutide directly, as discussed in tirzepatide vs semaglutide.

Both have large cardiovascular outcome trials in people with type 2 diabetes. In LEADER, 9,340 adults with type 2 diabetes and high heart risk took liraglutide or a placebo for about 3.8 years. Major heart events (heart attack, stroke or heart death) occurred in 13.0% on liraglutide against 14.9% on placebo, and deaths from any cause were also lower.

SURPASS-CVOT compared tirzepatide with dulaglutide (Trulicity), another GLP-1 drug already known to lower heart risk, in 13,299 adults over a median of about four years. Tirzepatide was at least as good (hazard ratio 0.92) but not proven better, and deaths from any cause were 16% lower. Because LEADER used a placebo and SURPASS-CVOT an active heart-protective drug, the results are not directly comparable. On August 28, 2026, the FDA approved Mounjaro to lower the risk of major heart events in adults with type 2 diabetes at high cardiovascular risk.

These are the label schedules; your prescriber sets your actual dose. Saxenda starts at 0.6 mg a day and goes up by 0.6 mg each week to 3 mg from week 5. A step can be delayed about a week if side effects are a problem. Adults who cannot tolerate 3 mg, or who have not lost at least 4% by week 16, should stop. Victoza starts at 0.6 mg a day for one week, then 1.2 mg, and can go up to 1.8 mg if needed.

Zepbound and Mounjaro start at 2.5 mg once a week for four weeks. That is a start dose, not a treatment dose; it then rises by 2.5 mg no sooner than every four weeks. Zepbound maintenance doses are 5, 10 or 15 mg, with 15 mg the maximum. What each step does is explained in tirzepatide dosage for weight loss. Zepbound comes in vials and a multi-dose pen, described in the Zepbound KwikPen guide.

Both mainly cause gut side effects, most often while the dose is rising. Label rates:

These come from separate trials, so they are not a direct comparison. All four brands carry the same boxed warning: thyroid C-cell tumors were seen in rodents, and the drugs should not be used by people with a personal or family history of medullary thyroid cancer (MTC) or multiple endocrine neoplasia type 2 (MEN 2). How long gut symptoms usually last on tirzepatide is covered in how long Mounjaro side effects last.

This is one area where liraglutide has an advantage. As of November 2026:

For teenagers with obesity but without type 2 diabetes, Saxenda or generic liraglutide 3 mg is the approved option of the two. The label says teens should stop if their BMI has not fallen by at least 1% after 12 weeks on the maintenance dose.

According to Novo Nordisk, brand Saxenda is being discontinued in the US, with the last shipments to wholesalers planned for late January 2027. Novo says this is a portfolio decision and not related to safety or quality. If you use Saxenda, plan ahead with your prescriber.

Generic liraglutide is already on the market. Teva launched an authorized generic of Victoza in June 2024, and Hikma's generic followed. In August 2025 the FDA approved Teva's generic of Saxenda, which launched the same day at an expected price about 30% below the brand. In February 2026 Biocon announced FDA approval of its own liraglutide for chronic weight management. Tirzepatide has no generic; why, and what to watch out for with copies sold online, is explained in is there a generic Zepbound.

Prices change often and depend on insurance, so check before you fill a prescription. These are the official figures we could verify as of November 2026:

For Medicare, a temporary GLP-1 Bridge program from July 1, 2026 to December 31, 2027 offers Zepbound KwikPen, Wegovy and Foundayo for $50 a month to people with a BMI of 35 or more, or 27 or more with a weight-related condition, with prior authorization. Saxenda and liraglutide are not covered by this program.

There is no label schedule for switching from liraglutide to tirzepatide, so your prescriber decides timing and starting dose; the usual tirzepatide start is 2.5 mg a week. The general approach to changing from one GLP-1 drug to tirzepatide is covered in switching from semaglutide to tirzepatide. Useful questions to bring to your appointment:

On that last point, weight regain after stopping is common with both drugs; the evidence for tirzepatide is in what happens when you stop tirzepatide.

Liraglutide and tirzepatide have never been compared head to head, but tirzepatide produced roughly two to three times more weight loss in its main trial, needs only one injection a week and had fewer people stopping for side effects in its own trials. Liraglutide still has a place as a cheaper generic, an option for teens with obesity from age 12, and a drug with proven heart benefits in type 2 diabetes. With brand Saxenda leaving the US market after January 2027, ask your prescriber which fits your goals and budget.

This article summarizes published research and official labeling for general information and is not medical advice. The main trials cited were funded by the drugs' manufacturers, Novo Nordisk (liraglutide) and Eli Lilly (tirzepatide).