What happens if you stop Mounjaro or Zepbound?

Zepbound's label includes a trial that stopped the drug on purpose; Mounjaro's does not, which is a difference in what is known rather than in what happens. On Zepbound's label, the people randomly assigned to stop gained 14% of body weight over the following 12 months while those who carried on lost 5.5% more. That figure belongs to Zepbound's trial, so this page does not apply it to Mounjaro.

Is Mounjaro or Zepbound better for weight loss?

Mounjaro reports 11.9% average weight loss and Zepbound 20.9%, each from its own trial. The two were not compared against each other, so the higher figure is not a result of a head-to-head and this page does not present it as one. What is comparable is what each costs, below.

Which is cheaper, Mounjaro or Zepbound?

Zepbound, at $449 a month against $499 — a difference of $50 a month, or $650 over a year counting the thirteen fills a 28-day month bills. Both figures are the maintenance price rather than an introductory rate.

Can you switch between Mounjaro and Zepbound?

They are the same molecule — tirzepatide — so switching is a prescribing decision rather than a change of drug.

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Mounjaro (tirzepatide, diabetes label) vs Zepbound (tirzepatide)

Verdict

Zepbound is the better choice of the two, winning on entry price (halfrx score 7.3 against 5.1).

Computed from the stored fields, so it moves when a price does. Nothing here is written by hand or by a model.

Which is cheaper, Mounjaro (tirzepatide, diabetes label) or Zepbound (tirzepatide)?

Mounjaro (tirzepatide, diabetes label) is $499 a month all-in, read from its own page on 2026-09-21; Zepbound (tirzepatide) is $299–$699, read from its own page on 2026-08-19. At the maintenance dose the gap is $50 a month, which is $650 across a year, counting 13 fills. Trial weight loss was 11.9% against 20.9%, from separate trials with different populations, so the gap is not a measured difference between the two. Every axis below is computed from stored fields rather than written by hand, so the comparison moves when a price does. They were last checked on 2026-09-21 and 2026-08-19. Neither carries an FTC action, a state action, a BBB F grade or an FDA warning letter. The published formula scores them 5.1 and 7.3 out of 10, arithmetic over the same stored fields rather than an editor's preference.

Head to head

Mounjaro (tirzepatide, diabetes label) against Zepbound (tirzepatide), one row per axis, with the side that wins each axis marked.
What decides it	Mounjaro $499/mo	Zepbound $299–$699/mo
Entry priceZepbound (tirzepatide) is $200/mo cheaper to start — $299 against $499.	—	✓ better here
Regulatory and complaint riskNeither carries a lawsuit, an FDA warning letter or a supply-risk flag.	tied	tied
Average weight loss in trialsMounjaro (tirzepatide, diabetes label) reports 11.9% and Zepbound (tirzepatide) 20.9%, each from its own trial. They were not compared against each other, and the populations, durations and endpoints differ, so the higher number is not a better result — it is a different study.	not comparable	not comparable

What the trials, the titration and a year actually say

Axis	Mounjaro	Zepbound
Mean weight loss in the cited trial	11.9%	20.9%
The trial that figure comes from	No percentage of body weight appears anywhere on the Mounjaro label, which has no weight-management section: every trial on it is a diabetes trial and reports weight in kilograms. This figure is worked out from the label's own kilograms — 11.2 kg lost from a 93.8 kg mean baseline at week 40 on 15 mg, in SURPASS-2 against semaglutide — and is an arithmetic step the label does not take.	SURMOUNT-1, Study 1 on the label, 72 weeks: 20.9% mean weight loss at 15 mg against 3.1% on placebo, intention-to-treat.
Maintenance dose	2.5 mg to 15 mg once weekly, set by blood sugar control	5 mg, 10 mg or 15 mg once weekly
Earliest week you reach it	—	week 5
Year one at the published price of every step	$6,487	$5,637

Trial percentages are quoted from the label or the named trial beside them. They are not a head-to-head result: different populations, different durations, different endpoints. That is why the comparison above scores this axis as not comparable rather than awarding it to the higher number. The year-one figures walk each titration step at its published price — Mounjaro has one price at every dose, so there is no step to walk — and count the thirteen fills a 28-day month bills. The full arithmetic is published.

Go to Mounjaro ↗Go to Zepbound ↗

These two are comparable — here is what the price gap is a gap in

Both are branded tirzepatide injections, so the gap between the two prices is in what is charged rather than in what you receive.
Against every medication on this site with a verified maintenance price, Mounjaro (tirzepatide, diabetes label) is the 9th cheapest of 9 and Zepbound (tirzepatide) the 8th — the cheapest of them all is $75.

Eli Lilly

Mounjaro (tirzepatide, diabetes label)

5.1

$499/mo all-in

verified 2026-09-21

Off-label for weightBoxed warning

Eli Lilly

Zepbound (tirzepatide)

7.3

$299–$699/mo all-in

checked 2026-08-19, 46 days ago, past the 45-day window

Price conditional on refill timingBoxed warning

Mounjaro (tirzepatide, diabetes label)

Pros

+Same tirzepatide molecule as Zepbound, the most effective approved weight-loss agent.[4]
+On-label and readily covered if you have type 2 diabetes.[4]

Cons

−Off-label for weight loss without diabetes — expect insurance denial and prescriber reluctance.[4]
−Self-pay is $499 a month at every strength through LillyDirect, with no cheaper starting tier: Zepbound, the same molecule on the weight-loss label, is $299 at 2.5 mg and $449 at 7.5 mg and above through the same pharmacy. For weight loss, Zepbound is the cheaper route to the same molecule.[1]
−Weekly injection with the same GI side-effect profile.[4]

Sources

Zepbound (tirzepatide)

Pros

+Highest average weight loss of any approved medication — around 20.9% at the 15 mg dose in SURMOUNT-1.[2]
+Dual GIP/GLP-1 agonist, a different mechanism from semaglutide, so it often works for people semaglutide failed.[2]
+$299/mo at the starting dose direct from Lilly against a $1,086 list price, with home delivery of vials or pens at the same price.[1]
+Also approved for obstructive sleep apnea, which can unlock insurance coverage that a weight indication alone would not.[2]
+If you are commercially insured with coverage, Lilly's card can bring it to as little as $25 a month.[1]

Cons

−Weekly injection with the usual GI side effects — nausea, vomiting, diarrhea and constipation are the common discontinuation reasons.[2]
−The advertised $449 ceiling is conditional. It holds only while you refill within 45 days; lapse once and 10 mg and above cost $699 — 56% more than the number in the advert.[1]
−Lilly defines a month as 28 days, so a year is 13 fills, not 12. At $449 that is $5,837 a year against the $5,388 that 'per month' implies — $449 of hidden annual cost.[1]
−$1,086 list price if you have no coverage and do not use LillyDirect self-pay.[1]
−Weight regain after stopping is the documented norm, so the cost is ongoing rather than a course.[2]
−2.5 mg is a starting dose and is not approved for maintenance, so the $299 headline is a price nobody stays on.[1]

Sources

Mounjaro side effects →Zepbound side effects →Mounjaro dosage →Zepbound dosage →

Comparisons are computed from the fields on each card, not written by hand or by a model, so they change when the data does. Information only, not medical advice. halfrx may earn a commission from some links, which never changes what a comparison says.

Everything on Mounjaro

Everything on Zepbound

Mounjaro against Zepbound, answered

What happens if you stop Mounjaro or Zepbound?: Zepbound's label includes a trial that stopped the drug on purpose; Mounjaro's does not, which is a difference in what is known rather than in what happens. On Zepbound's label, the people randomly assigned to stop gained 14% of body weight over the following 12 months while those who carried on lost 5.5% more. That figure belongs to Zepbound's trial, so this page does not apply it to Mounjaro.
Is Mounjaro or Zepbound better for weight loss?: Mounjaro reports 11.9% average weight loss and Zepbound 20.9%, each from its own trial. The two were not compared against each other, so the higher figure is not a result of a head-to-head and this page does not present it as one. What is comparable is what each costs, below.
Which is cheaper, Mounjaro or Zepbound?: Zepbound, at $449 a month against $499 — a difference of $50 a month, or $650 over a year counting the thirteen fills a 28-day month bills. Both figures are the maintenance price rather than an introductory rate.
Can you switch between Mounjaro and Zepbound?: They are the same molecule — tirzepatide — so switching is a prescribing decision rather than a change of drug.