Ozempic vs Qsymia: Off-Label Injection Against an Approved Oral
Ozempic (semaglutide, Novo Nordisk) vs Qsymia (phentermine-topiramate, VIVUS LLC)
Last verified May 2026
The verdict
Ozempic's weight figure here is extrapolated from semaglutide's trial programs rather than measured under its own label, which is a weaker claim than the number looks. Qsymia's −10.9% comes from EQUIP at the top dose, in an obesity population, on label. Cost runs $599–$899 against $100–$200 brand or about $50 generic. On evidence-for-this-purpose, the cheap oral is on firmer ground than the expensive off-label injection.
Side-by-side comparison
| Field | Ozempic | Qsymia |
|---|---|---|
| FDA Indication | Type 2 diabetes only (weight loss is off-label) | Chronic weight management (BMI 30+, or 27+ with comorbidity) |
| Mechanism | GLP-1 receptor agonist (incretin mimetic) | Sympathomimetic amine + GABA modulator/carbonic anhydrase inhibitor |
| Route & Frequency | Subcutaneous injection, once weekly | Oral capsule, once daily (morning) |
| Average Weight Loss (56 wk) | ~10-15% off-label (extrapolated from SUSTAIN/STEP semaglutide data) | -10.9% (EQUIP, top dose 15/92 mg) |
| Pivotal Trial Result | Not studied for weight loss at this brand/dose; Wegovy STEP-1 -14.9% | -9.8% placebo-subtracted at 56 wk (CONQUER) |
| Cash Price (US, monthly) | $599-$899 (NovoCare direct) | $100-$200 brand; ~$50 generic phentermine-topiramate |
| Pregnancy Safety / REMS | Not recommended in pregnancy; no REMS program | REMS required: teratogenic (cleft lip/palate); contraception + monthly pregnancy testing mandated |
| Common Side Effects | Nausea, vomiting, diarrhea, constipation | Paresthesia, dry mouth, dysgeusia, insomnia, cognitive slowing |
What each one costs in the compounded market
Standing monthly cash prices from the 556 sellers on this register. These are compounded preparations, not the approved products compared above.
Ozempic — semaglutide
from $79 /mo
283 sellers publish a standing price; the median is $174 a month.
Qsymia — phentermine-topiramate
No seller on this register publishes a compounded price for it. For a drug still in trials that is expected — and anyone selling it anyway is doing so outside the system this register covers.
⚠ A compounded preparation is not the approved product. No agency has reviewed that specific preparation for safety, effectiveness or manufacturing quality, and the legal ground under compounding these molecules narrowed when the shortages closed. The price gap is real, and so is the difference in oversight. Every seller, with its price record.
Frequently asked questions
Which works better for weight loss, Ozempic or Qsymia?
Ozempic recorded ~10-15% off-label (extrapolated from SUSTAIN/STEP semaglutide data); Qsymia recorded -10.9% (EQUIP, top dose 15/92 mg). ⚠ These come from separate trials with different protocols and populations, so the gap between two numbers from two studies is weaker evidence than it looks. No head-to-head trial of this pair is on record here.
Are Ozempic and Qsymia the same drug?
No. Ozempic is semaglutide and Qsymia is phentermine-topiramate — different molecules, and they work differently: GLP-1 receptor agonist (incretin mimetic) against Sympathomimetic amine + GABA modulator/carbonic anhydrase inhibitor. Results with one do not predict results with the other.
Is Ozempic or Qsymia cheaper?
On the manufacturers' own cash pricing: Ozempic at $599-$899 (NovoCare direct), Qsymia at $100-$200 brand; ~$50 generic phentermine-topiramate. ⚠ That is the list-price comparison, and it is not what most people pay. What you actually pay depends on whether your plan covers it, which formulary tier it sits in, and whether you have met your deductible — and for many people the honest comparison is between an insured copay and a cash-pay compounded alternative rather than between these two figures.
Which has worse side effects, Ozempic or Qsymia?
The most common adverse event reported was Nausea, vomiting, diarrhea, constipation for Ozempic and Paresthesia, dry mouth, dysgeusia, insomnia, cognitive slowing for Qsymia. ⚠ Rates come from separate trial populations and are not a like-for-like comparison. In practice how fast the dose is escalated affects tolerability at least as much as which drug it is, which is one reason a slower titration is worth asking for.
What does a compounded version of each actually cost?
Across the 556 sellers in this register, the cheapest standing monthly cash prices we hold are semaglutide from $79 a month. ⛔ A compounded preparation is not the approved product: no agency has reviewed that specific preparation for safety, effectiveness or manufacturing quality, and the legal ground under compounding these molecules narrowed once the shortages closed. The price gap is real and so is the difference in oversight.
Can I switch from Ozempic to Qsymia?
Yes, with a prescriber. Expect to re-titrate from the bottom of the new drug's ladder rather than starting where you left off: these are different molecules and tolerance to one does not transfer to the other. Both the old drug's washout and the new drug's schedule apply.
Which one should I ask for?
That is a prescriber's call, and anyone answering it from a table is guessing. What a page like this can do is tell you what the trials measured, what the manufacturers charge, and where the evidence is still missing, so the conversation starts from the record rather than from an advertisement.
References
- 1.Allison DB, et al. Controlled-release phentermine/topiramate in severely obese adults: a randomized controlled trial (EQUIP) Obesity (Silver Spring). 2012. PMID: 22051941.
- 2.Gadde KM, et al. Effects of low-dose, controlled-release, phentermine plus topiramate combination on weight and associated comorbidities in overweight and obese adults (CONQUER): a randomised, placebo-controlled, phase 3 trial Lancet. 2011. PMID: 21481449.
- 3.FDA / Novo Nordisk; FDA / VIVUS Ozempic (semaglutide) and Qsymia (phentermine-topiramate ER) prescribing information via DailyMed DailyMed (NLM). 2024. PMID: N/A.
Related comparisons
- Wegovy vs Zepbound
- Ozempic vs Mounjaro
- Semaglutide vs Tirzepatide
- Rybelsus vs Ozempic
- Mounjaro vs Zepbound
- Foundayo vs Rybelsus
See the full drug-vs-drug verdict index or provider rankings.