What does a pound actually cost?

These drugs are priced flat but work in percentages, so the cheapest drug and the best value are not the same thing. Enter your weight to see what a pound actually costs on each.

Cost per pound calculator

Trial averages were measured at roughly 231 lb, so results near that weight track the published data most closely.

The one direct comparison that exists

SURMOUNT-5: tirzepatide -20.2% against semaglutide -13.7% mean body-weight change. The only direct comparison of these two drugs. Least-squares mean percent change in body weight at 72 weeks, p<0.001. Discontinuation for gastrointestinal side effects was higher on semaglutide (5.6%) than tirzepatide (2.7%).

Randomised open-label phase 3b, 751 adults with obesity or overweight plus a comorbidity, no diabetes, 72 weeks, maximum tolerated dose · read the trial

This matters more than the table below, because everything else on this page compares numbers from different trials with different populations and different analysis methods. When a head-to-head exists, it beats arithmetic.

What each trial actually found

DrugMean lossTrialCash priceYear cost
Zepbound (tirzepatide)
15 mg weekly
−20.9%
placebo −3.1%
SURMOUNT-1 · n=2,539 · 72 weeks · efficacy estimand $399/mo
LillyDirect — Zepbound Self Pay
$4,788
Wegovy (semaglutide)
2.4 mg weekly
−14.9%
placebo −2.4%
STEP 1 · n=1,961 · 68 weeks · treatment policy estimand $349/mo
NovoCare Pharmacy
$4,188
Foundayo (orforglipron)
36 mg daily, oral
−11.2%
placebo −2.1%
ATTAIN-1 · n=3,127 · 72 weeks · treatment regimen estimand $299/mo
LillyDirect — Foundayo
$3,588

Other doses, for completeness: Zepbound — −19.5% at 10 mg, −15.0% at 5 mg. Wegovy — −15.3 kg absolute versus −2.6 kg on placebo. Foundayo — −8.4% at 12 mg, −7.5% at 6 mg. Lilly also reports −12.4% at 36 mg under the efficacy estimand; we use the more conservative figure..

The compounded question

Compounded semaglutide and tirzepatide are much cheaper, and they have no trials of their own. Every efficacy number you see attached to a compounded product is borrowed from the branded trials above. That may be a reasonable inference for the same molecule at the same dose — and it is still an inference, not a result. Our index lists compounded channels from $139/month, and who actually makes them is a separate question worth asking.

The result that surprised us

The most expensive drug is the best value at every weight, and the ranking never changes.

We expected the ordering to flip somewhere — cheap drug wins for lighter people, effective drug wins for heavier ones. It does not, and the reason is arithmetic rather than pharmacology. Cost per pound is annual cost divided by (your weight × the percentage), so your weight sits in the denominator for every drug equally and cancels out of the comparison. Only the ratio of price to efficacy decides the order, and that ratio does not depend on you at all.

So your weight changes how much each drug costs per pound — heavier means better value across the board — but never which is cheapest per pound. Zepbound costs the most per month and still wins, because it is enough more effective to cover the difference.

The ordering would only flip if a price changed. Foundayo would have to fall below roughly $214/month, or Zepbound rise above about $558, before the current ranking broke — which is worth knowing, because these prices have moved sharply and recently.

What this number does not tell you

  • These are averages from trials, not predictions for you. In every trial some participants lost far more and some lost nothing.
  • Comparing across trials is not the same as comparing drugs. Different populations, durations and analysis methods change the number before the drug does — which is why the head-to-head result above is worth more than any cross-trial arithmetic.
  • Trial participants received structured lifestyle support alongside the drug. Results outside that setting are typically smaller.
  • Every trial here ran 68 to 72 weeks. Weight regain after stopping is well documented and is not captured by any figure on this page.
  • The cost side assumes you stay on the drug for a full year at the price shown. Dose escalation, insurance changes, and price moves all break that assumption.

Educational arithmetic, not medical advice, and not a recommendation of any drug. Weight-loss figures are published trial averages, each linked to its source; your result will differ. Which medication is appropriate for you depends on your health history, other conditions and tolerance, and that is a conversation for a clinician who can see all of it.

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