Contrave vs Qsymia

Contrave combines naltrexone, used in opioid and alcohol dependence, with bupropion, an antidepressant. Qsymia combines phentermine, an appetite suppressant approved on its own for short-term use, with topiramate, a medication approved for epilepsy and migraine prevention.

Both labels state that the mechanism producing weight loss is not fully understood.

Contrave carries a boxed warning about suicidal thoughts and behaviours, which is the class warning attached to bupropion as an antidepressant. Its label also contraindicates seizure disorders and chronic opioid use.

Qsymia has no boxed warning, but its label contraindicates pregnancy and requires pregnancy testing before and monthly during treatment, because topiramate increases the risk of oral clefts when taken in the first trimester.

Both labels cover adults with obesity, or with overweight plus at least one weight-related condition. The Qsymia label additionally covers patients aged 12 and older. The exact wording of each indication is in the table above.

The Contrave label sets a checkpoint. Response to therapy should be evaluated after 12 weeks at the maintenance dosage, and if a patient has not lost at least 5 percent of baseline body weight, the label instructs that Contrave be discontinued, because it is unlikely that continued treatment will achieve and sustain clinically meaningful weight loss. A stopping rule written into the dosing instructions is unusual, and it is the label's own.

The Qsymia label instead warns about how to come off it: the highest dosage is to be discontinued gradually, to prevent a possible seizure. That instruction comes from the topiramate component and has no counterpart in the Contrave label.

Neither document describes moving from one of these products to the other. That question is not answered by either label, and this page does not invent an answer to it.

The two are not in the same position on generics, and that is a matter of record rather than opinion. The FDA application register lists approved generic applications for the phentermine and topiramate combination, and none for the naltrexone and bupropion combination.

On actual figures the picture is lopsided. Qsymia appears in the NADAC file published by the Centers for Medicare and Medicaid Services, so a pharmacy acquisition cost can be shown for it. Contrave does not appear in that file at all. An absent row is not a high price and not a low one; it is an absence, and treating it as evidence either way would be wrong.

Two further limits are worth stating plainly. NADAC records what pharmacies pay to buy a medication, not what a person pays at a counter. And neither FDA label discusses price at any point, because that is not what a label is for. Anyone comparing these two on out-of-pocket cost is asking a question these documents cannot answer.

Both labels report their most common adverse reactions, and the two lists overlap on four entries: dizziness, insomnia, constipation and dry mouth. Beyond those, they diverge. The Contrave list adds nausea, headache, vomiting and diarrhoea. The Qsymia list adds paraesthesia and dysgeusia, which is altered taste, and contains no gastrointestinal entry other than constipation.

The more important difference is in how the lists were built, and it is easy to miss. Contrave reports reactions occurring at 5 percent or more. Qsymia reports reactions occurring at 5 percent or more that were also at least 1.5 times as frequent as with placebo. A reaction reported by 6 percent of people on Qsymia and 5 percent of people on placebo would be excluded from the Qsymia list by that second condition, while the same numbers would put it on the Contrave list. The two lists are therefore not directly comparable, and a shorter list is not evidence of a better tolerated medication.

The Qsymia list above is the adult one. Because that label also covers patients aged 12 and older, it carries a second list for them, built at yet another threshold, 4 percent or more and greater than placebo, and its entries are different again: depression, dizziness, arthralgia, pyrexia, influenza and ligament sprain. Contrave, whose own boxed warning states that it is not approved for use in paediatric patients, has no equivalent list.

Neither document sets its figures next to the other product. There is no head-to-head trial of these two medications in either label, so any comparison of rates between them is a comparison of two separately conducted studies with different populations and different reporting rules.

The reactions above are the frequent ones. They are not the ones the labels treat as most serious, and the two sets barely intersect. The serious material sits in the warnings, and there the documents are furthest apart.

Contrave carries a boxed warning on suicidal thinking and behaviour, and its warnings section covers seizures, raised blood pressure and heart rate, hepatotoxicity from the naltrexone component, and angle-closure glaucoma. It is contraindicated in uncontrolled hypertension and in seizure disorder. Qsymia has no boxed warning, but its label carries embryo-fetal toxicity, requires a negative pregnancy test before treatment and monthly during it, and is distributed under a Risk Evaluation and Mitigation Strategy. It also carries a warning on suicidal behaviour and ideation, so that concern is present in both documents, boxed in one and not in the other.

Anyone weighing the two is weighing both lists at once, and the labels do not do that weighing for the reader.

A large share of the searches that reach this page ask what reviews say, or what people report on forums. That is a request for lived experience, and an FDA label does not contain any. This page does not contain any either, and the reason is worth stating rather than leaving as a gap.

What the labels do contain is the systematic version of the same question. Adverse reactions in a label come from participants in clinical trials, counted against a placebo group, at a stated threshold, whether or not the participant chose to speak about it. A review is written by someone who decided to write one. Both describe experience; only one of them was collected in a way that supports a rate.

There are real questions where reviews hold something the documents do not: what the medication costs at a counter, whether an insurer covered it, how the first weeks felt. This site does not answer those, because it cannot source them, and filling the gap with a plausible summary of other people's posts would be inventing the part that matters most.