What happens if you stop Qsymia or Wegovy?

Wegovy's label includes a trial that stopped the drug on purpose; Qsymia's does not, which is a difference in what is known rather than in what happens. On Wegovy's label, the people randomly assigned to stop gained 6.9% of body weight over the following 11 months while those who carried on lost 7.9% more. That figure belongs to Wegovy's trial, so this page does not apply it to Qsymia.

Is Qsymia or Wegovy better for weight loss?

Qsymia reports 9.8% average weight loss and Wegovy 14.9%, 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, Qsymia or Wegovy?

Qsymia, at $75 a month against $349 — a difference of $274 a month, or $3,637 over a year counting 12 fills a year for Qsymia and 13 for Wegovy. Both figures are the maintenance price rather than an introductory rate. Above the maintenance dose, the optional higher dose costs more: Wegovy at 7.2 mg, Wegovy HD is $399 a month.

Can you switch between Qsymia and Wegovy?

They are different molecules, so this is a change of medication rather than of brand, and the one you move to is started on its own dosing schedule.

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Qsymia (phentermine/topiramate) vs Wegovy (semaglutide injection)

Verdict

Qsymia is the better choice of the two, winning on entry price (halfrx score 7.1 against 6.9).

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, Qsymia (phentermine/topiramate) or Wegovy (semaglutide injection)?

Qsymia (phentermine/topiramate) is $66–$75 a month all-in, read from its own page on 2026-09-22; Wegovy (semaglutide injection) is $199–$399, read from its own page on 2026-09-22. At the maintenance dose the gap is $274 a month, which is $3,637 across a year, counting 12 fills for Qsymia (phentermine/topiramate) and 13 for Wegovy (semaglutide injection). Trial weight loss was 9.8% against 14.9%, 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. Both were last checked on 2026-09-22. Neither carries an FTC action, a state action, a BBB F grade or an FDA warning letter. The published formula scores them 7.1 and 6.9 out of 10, arithmetic over the same stored fields rather than an editor's preference.

Head to head

Qsymia (phentermine/topiramate) against Wegovy (semaglutide injection), one row per axis, with the side that wins each axis marked.
What decides it	Qsymia $66–$75/mo	Wegovy $199–$399/mo
Entry priceQsymia (phentermine/topiramate) is $133/mo cheaper to start — $66 against $199.	✓ better here	—
Regulatory and complaint riskNeither carries a lawsuit, an FDA warning letter or a supply-risk flag.	tied	tied
Average weight loss in trialsQsymia (phentermine/topiramate) reports 9.8% and Wegovy (semaglutide injection) 14.9%, 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	Qsymia	Wegovy
Mean weight loss in the cited trial	9.8%	14.9%
The trial that figure comes from	CONQUER, Study 2 on the label, 56 weeks: 9.8% mean weight loss at the 15 mg/92 mg dose against 1.2% on placebo, intention-to-treat.	STEP 1, Study 2 on the label (NCT03548935), 68 weeks: 14.9% mean weight loss at 2.4 mg against 2.4% on placebo, intention-to-treat.
Maintenance dose	7.5 mg / 46 mg daily	2.4 mg once weekly, or 1.7 mg
Earliest week you reach it	week 3	week 17
Year one at the published price of every step	No titration prices recorded	$4,237

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 and count the thirteen fills a 28-day month bills. The full arithmetic is published.

Go to Qsymia ↗Go to Wegovy ↗

Read the price gap carefully: these two are not the same purchase

These are different molecules — phentermine and topiramate against semaglutide — so this is a comparison of two treatments, not of two prices for one.
Against every medication on this site with a verified maintenance price, Qsymia (phentermine/topiramate) is the 1st cheapest of 9 and Wegovy (semaglutide injection) the 5th — the cheapest of them all is $75.

Vivus

Qsymia (phentermine/topiramate)

7.1

$66–$75/mo all-in

verified 2026-09-22

Weaker moleculeREMS restrictedControlled substance

Novo Nordisk

Wegovy (semaglutide injection)

6.9

$199–$399/mo all-in

verified 2026-09-22

Boxed warning

Qsymia (phentermine/topiramate)

Pros

+9.8% mean weight loss at the top dose in CONQUER, intention-to-treat — the strongest result available from an oral non-GLP-1 drug.[2]
+$74.99/mo through Qsymia Engage home delivery for anyone, $65.99 for Costco members, and generic phentermine/topiramate ER runs roughly $50–$100 — an order of magnitude under branded GLP-1 list prices.[1]
+Approved down to age 12, as Wegovy and Saxenda are; Zepbound is for adults only.[2]

Cons

−Topiramate raises the risk of oral clefts when taken in the first trimester. The label recommends a negative pregnancy test before starting and every month during treatment, with effective contraception, and Qsymia is dispensed only through pharmacies certified under an FDA REMS.[6]
−Phentermine is a controlled substance with cardiovascular contraindications.[2]
−Cognitive side effects — word-finding difficulty and trouble concentrating — are common enough to be a frequent reason people stop.[2]
−Its 9.8% in CONQUER is under half the 20.9% tirzepatide reached in SURMOUNT-1 on Zepbound's label, a separate trial in a different population, so this is not a head-to-head result.[7]

Sources

Wegovy (semaglutide injection)

Pros

+One flat $349 across every standard dose from 0.25 to 2.4 mg — no dose-escalation penalty and no refill deadline attached, unlike Lilly's conditional pricing on Zepbound.[1]
+New patients pay $199 for the first two fills through 31 December 2026 — the first two of the four titration months.[2]
+Approved for cardiovascular risk reduction, not only weight — the strongest insurance-coverage argument in the category.[1]
+The longest real-world safety record of any modern weight-loss GLP-1.[1]
+Commercially insured, the savings card can bring it to $25 a month, capped at $100 of savings per month.[2]

Cons

−$1,349 monthly list price without insurance or the self-pay program.[1]
−Weaker than tirzepatide where the two were tested head to head: in SURMOUNT-5, weight fell 13.7% on semaglutide against 20.2% on tirzepatide over 72 weeks.[6]
−A month is one box of four weekly pens, so a year takes 13 boxes, not 12: $4,537 at $349 rather than the $4,188 that 'per month' implies.[1]
−The new high dose, Wegovy HD 7.2 mg, sits outside the flat price at $399.[1]
−Weekly injection, refrigerated storage, GI side effects during titration, and weight regain after stopping is the documented norm.[3]

Sources

Qsymia side effects →Wegovy side effects →Qsymia dosage →Wegovy 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 Qsymia

Everything on Wegovy

Qsymia against Wegovy, answered

What happens if you stop Qsymia or Wegovy?: Wegovy's label includes a trial that stopped the drug on purpose; Qsymia's does not, which is a difference in what is known rather than in what happens. On Wegovy's label, the people randomly assigned to stop gained 6.9% of body weight over the following 11 months while those who carried on lost 7.9% more. That figure belongs to Wegovy's trial, so this page does not apply it to Qsymia.
Is Qsymia or Wegovy better for weight loss?: Qsymia reports 9.8% average weight loss and Wegovy 14.9%, 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, Qsymia or Wegovy?: Qsymia, at $75 a month against $349 — a difference of $274 a month, or $3,637 over a year counting 12 fills a year for Qsymia and 13 for Wegovy. Both figures are the maintenance price rather than an introductory rate. Above the maintenance dose, the optional higher dose costs more: Wegovy at 7.2 mg, Wegovy HD is $399 a month.
Can you switch between Qsymia and Wegovy?: They are different molecules, so this is a change of medication rather than of brand, and the one you move to is started on its own dosing schedule.