Semaglutide vs Tirzepatide: Cost, Weight Loss, and Which to Compound (2026)

Two molecules dominate the GLP-1 conversation, and patients shopping for a compounded option have to pick one before they ever see a price. This is the honest comparison: what the trials actually show, what each costs in compounded form, and how to decide which one belongs in your vial.

The short answer

Tirzepatide produces more weight loss. Semaglutide is usually cheaper and has the deeper cardiovascular-outcomes evidence. If your single priority is maximum weight reduction, tirzepatide leads the trials. If your priority is cost, proven heart-health benefit, or you simply tolerate it better, semaglutide is compelling. Both are legitimate; neither compounded version is FDA-approved.

What they are, mechanically

Semaglutide is a single-pathway drug: a GLP-1 receptor agonist. It mimics the GLP-1 hormone, which slows gastric emptying, increases satiety, and improves insulin response. It is the molecule in Ozempic (type 2 diabetes) and Wegovy (weight management).

Tirzepatide is a dual agonist: it activates both the GLP-1 and the GIP receptors. Adding the GIP pathway appears to amplify the metabolic effect, which is the leading explanation for why tirzepatide outperforms semaglutide on weight in head-to-head data. It is the molecule in Mounjaro (type 2 diabetes) and Zepbound (weight management).

The trial data, side by side

The numbers below are from the pivotal Phase 3 trials, all published in the New England Journal of Medicine. These studied brand-name product; the compounded molecule is identical, but compounded formulations have not been trialed separately — the honest caveat.

Trial	Drug & dose	Population	Mean weight change
SURMOUNT-1 (2022)	Tirzepatide 15 mg	Obesity, no diabetes	up to −22.5% at 72 wks
SURMOUNT-1 (2022)	Tirzepatide 10 mg	Obesity, no diabetes	−19.5% at 72 wks
STEP-1 (2021)	Semaglutide 2.4 mg	Obesity, no diabetes	−14.9% at 68 wks
SURPASS-2 (2021)	Tirzepatide vs sema 1 mg	Type 2 diabetes	+47% more loss for tirz

The pattern is consistent: tirzepatide’s top doses moved more weight than semaglutide’s top dose, and in the one direct head-to-head (SURPASS-2, in diabetes), tirzepatide produced roughly 47% more weight loss than semaglutide 1 mg.

But semaglutide owns one category outright. In the SELECT trial (2023), semaglutide reduced major adverse cardiovascular events — heart attack, stroke, cardiovascular death — by about 20% in people with established cardiovascular disease and overweight or obesity but without diabetes. Tirzepatide does not yet have an equivalent completed cardiovascular-outcomes trial. If heart-health benefit is a goal, that distinction matters.

Cost: the compounded reality

Compounded semaglutide is generally a little cheaper than compounded tirzepatide, because tirzepatide carries a modest premium for targeting two receptors. Here is the spread across our tracked providers.

Molecule	Compounded range	Cheapest verified	Lowest fully-credentialed
Semaglutide	$99–$299/mo	Embody $99	NexLife $145 (flat)
Tirzepatide	$99–$329/mo	Embody $99	NexLife $186 (flat)

Two things to watch regardless of molecule. First, the advertised “from” price is almost always the starter dose; many providers raise the price as you titrate up, so a $99 teaser can become $280 at a maintenance dose. Second, flat pricing — where the monthly cost holds across the full titration — is worth more than a low first month over a 12-month course. For a deeper breakdown, see our cheapest compounded tirzepatide and cheapest compounded semaglutide rankings.

Brand context, for perspective

The same molecules cost an order of magnitude more in brand form:

• Wegovy (semaglutide) lists near $1,349/month at retail; Ozempic near $969.
• Zepbound (tirzepatide) lists near $1,086/month; Mounjaro near $1,135.
• Compounded versions of either run roughly $99–$329/month — the structural reason the compounded market grew several-fold during the shortage years.

Side effects: largely shared

Both molecules share the same GLP-1 side-effect profile, driven mostly by the GLP-1 pathway they have in common:

• Most common: nausea, diarrhea, constipation, vomiting — usually worst during dose escalation and easing with time.
• Less common but serious: gallbladder issues, pancreatitis, and a boxed warning (in the brand labels) regarding a theoretical thyroid C-cell tumor risk seen in rodents.

Anecdotally, some patients tolerate one molecule better than the other, which is a legitimate reason to switch even if the trial data favor tirzepatide on weight. Tolerability is individual, and titration speed matters more than the molecule for most early side effects.

How to choose

A simple decision framework:

• Maximum weight loss is the goal → tirzepatide. The trial data are the strongest of any approved obesity drug.
• Cost is the binding constraint → semaglutide, which runs slightly cheaper in compounded form.
• Established cardiovascular disease → semaglutide has the completed outcomes trial (SELECT).
• You’ve tried one and tolerated it poorly → switching molecules is reasonable; talk to your prescriber.
• You want predictable budgeting → prioritize a flat-pricing provider over the lowest teaser, in either molecule.

Bottom line

There is no universally “better” molecule — there is a better fit for your goal. Tirzepatide wins on weight loss in the trials; semaglutide wins on price and on proven cardiovascular benefit. In compounded form, both are legal, both deliver the same active ingredient as their brand-name counterparts, and neither is FDA-approved. Decide on the molecule first, then choose the provider by true price and credentials — not by whichever teaser number is lowest this week.

This article is educational and not medical advice. Compounded medications are not FDA-approved. Trial figures cited reflect brand-name product. Always consult a licensed clinician before starting, stopping, or changing any medication.