Semaglutide vs. Tirzepatide: The 2026 Verdict

Prices verified May 2026 · Compare GLP-1 Editorial Team

The Two Heavyweights

Semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound) are the two dominant GLP-1 receptor agonists on the market. Both are FDA-approved, injectable, and prescribed for weight management — but they work differently at the molecular level, produce different results in clinical trials, and come with different price tags.

This comparison draws on published Phase 3 trial data and current market pricing. No provider paid for placement in this analysis.

How They Work

Semaglutide is a single-receptor agonist: it mimics GLP-1, a gut hormone that signals fullness to the brain and slows gastric emptying. Tirzepatide is a dual-receptor agonist — it activates both GLP-1 and GIP receptors, creating a two-pronged effect on appetite, insulin sensitivity, and glucose metabolism.

The dual-agonist mechanism is why tirzepatide generally produces greater weight loss and more pronounced effects on blood sugar. Whether that translates to a meaningfully better outcome for you depends on several factors we'll break down below.

Weight Loss: The Numbers

In head-to-head terms, tirzepatide consistently produces more weight loss than semaglutide across comparable trial designs. The SURMOUNT-1 trial showed participants on the highest dose of tirzepatide (15mg) losing an average of 22.5% of body weight over 72 weeks. Semaglutide's STEP 1 trial showed 16.9% on the 2.4mg dose over 68 weeks.

Direct comparison data from the SURMOUNT-5 trial (tirzepatide vs. semaglutide head-to-head) showed tirzepatide producing roughly 47% more weight loss than semaglutide at maximum doses. That's a meaningful clinical difference.

Side Effects

Both medications share the same primary side effects: nausea, vomiting, diarrhea, and constipation. These are most common during dose titration (the first 4–8 weeks) and generally improve with time.

Semaglutide has a longer post-market safety record. The SELECT cardiovascular outcomes trial demonstrated a 20% reduction in major adverse cardiovascular events — a significant finding that tirzepatide hasn't yet matched in published data (its SURPASS-CVOT trial is still underway).

Neither medication should be used by people with a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2.

Cost Comparison

Brand-name pricing is comparable: both run $1,000+ per month at retail without insurance. Manufacturer savings programs (NovoCare for Wegovy, LillyDirect for Zepbound) can reduce this for eligible patients.

Where pricing diverges sharply is in the compounded market. Compounded semaglutide is widely available from telehealth providers starting around $146–299/month. Compounded tirzepatide is harder to find due to ongoing FDA enforcement actions and generally costs $199–400/month where available.

Our Verdict

If maximum weight loss is your primary goal and cost isn't the deciding factor, tirzepatide has the edge — the clinical data is clear. If you're cost-conscious, want a longer safety track record, or prefer the broader availability of compounded options, semaglutide is the pragmatic choice.

Both are effective medications. Neither is a wrong choice. The "best" one is the one your provider recommends based on your health profile and the one you can afford to stay on long-term.

Providers Offering Both Medications