Tirzepatide · 3 min read
SURMOUNT-5 settled the efficacy question directly: 20.2% vs 13.7% average weight loss at 72 weeks. What the head-to-head trial showed, where semaglutide still wins, and what each costs in 2026.
SURMOUNT-5 settled the efficacy question directly: 20.2% vs 13.7% average weight loss at 72 weeks. What the head-to-head trial showed, where semaglutide still wins, and what each costs in 2026.
For three years the tirzepatide-versus-semaglutide question was answered by comparing separate trials. Since 2025 it has a direct answer: the SURMOUNT-5 trial randomized 751 adults with obesity, without diabetes, to maximum-tolerated doses of each drug and followed them for 72 weeks. Tirzepatide produced an average 20.2% body-weight reduction against 13.7% for semaglutide 2.4 mg — roughly 50 pounds versus 33 for the average participant — and a substantially larger share of tirzepatide patients cleared the 15%, 20%, and 25% loss thresholds.
Semaglutide is a GLP-1 receptor agonist. Tirzepatide is a dual agonist: it activates the GLP-1 receptor and the GIP receptor. The GIP activity appears to add appetite and energy-balance effects beyond GLP-1 agonism alone and may improve GI tolerability at equivalent efficacy. In practice, the dual mechanism shows up as a steeper and longer weight-loss curve: in SURMOUNT-5, the curves separated within the first months and never converged.
Semaglutide holds three cards tirzepatide cannot yet match. First, cardiovascular outcome evidence in non-diabetics: the SELECT trial (17,604 patients with cardiovascular disease and overweight or obesity, no diabetes) showed a 20% reduction in major adverse cardiovascular events, and Wegovy carries that indication. Tirzepatide's SURPASS-CVOT results, reported in 2025, showed cardiovascular benefit against an active comparator in type 2 diabetes — strong, but a different population. Second, an oral option: the Wegovy tablet launched in early 2026, and no oral tirzepatide exists. Third, price at the low end: verified compounded semaglutide runs $133 to $299 a month in our feed versus $215 to $597 for compounded tirzepatide, and brand Wegovy's flat $349 undercuts Zepbound's $449 maintenance-dose rate.
At standing monthly rates in our database: the cheapest verified compounded semaglutide is $133 (Oak Longevity) and the cheapest verified compounded tirzepatide is $215 (NexLife) — an $82 monthly premium for the stronger molecule, or about $984 a year. On the brand side, Wegovy's $349-at-every-dose structure beats Zepbound's $299/$399/$449 dose-scaled structure at maintenance, though Zepbound's $299 starter vial is cheaper for month one. Several programs price both molecules, and the in-house premium for tirzepatide ranges from about $70 a month (NexLife: $145 vs $215) to over $100 (Mochi: $178 vs $278 all-in). Our tirzepatide and semaglutide rankings carry every figure with its conditions.
The evidence supports a simple frame. If maximum weight loss is the goal and budget allows, tirzepatide is the stronger drug on averages and thresholds. If cardiovascular risk reduction in established disease is the goal, semaglutide has the outcomes label. If needles are the obstacle, semaglutide has the pill. If price is the constraint, semaglutide is cheaper at every tier of the market. And if you respond poorly to one, switching to the other is a real, studied option — see switching from semaglutide to tirzepatide. All of it belongs in a conversation with a clinician who knows your history; head-to-head averages are not individual predictions.
On trial averages, yes: SURMOUNT-5 showed 20.2% average body-weight loss for tirzepatide versus 13.7% for semaglutide 2.4 mg at 72 weeks in a direct head-to-head. Individual responses vary widely, and semaglutide retains advantages in cardiovascular outcome evidence, an oral option, and price.
In our verified feed, the cheapest compounded tirzepatide ($215/mo) runs $82/mo more than the cheapest compounded semaglutide ($133/mo). On brand pricing, Zepbound's $449 maintenance rate runs $100/mo more than Wegovy's flat $349.
Yes, clinicians commonly transition patients, generally starting tirzepatide at a low-to-intermediate dose rather than the top of the ladder. It should be planned with your prescriber.