Both Qsymia and Belviq, two FDA-approved weight loss drugs, have pros and cons, and the decision to choose one over the other is made on an individual basis, according to PsychCentral. People reportedly lose more weight taking Qsymia, but it has side effects and specific contraindications.
In one study, people taking Qsymia for up to one year lost an average of 9 percent over those taking the placebo, according to PsychCentral. More than 70 percent of people taking Qsymia lost more than 5 percent of their body weight. In comparison, those taking Belviq lost between 3 to 3.7 percent of their body weight over those taking the placebo, and after taking Belviq for one or two years, 47 percent of people lost more than 5 percent of their body weight. While it seems that Qsymia is a better choice for weight loss, people who have hyperthyroidism, are taking an MAOI antidepressant, or are allergic to phentermine or topiramate cannot take it.
Other factors to consider are the side effects the medications may cause, notes Mayo Clinic. Belviq can cause headache, nausea and fatigue in people using it. Qsymia, on the other hand, can cause insomnia, a pins-and-needles feeling and changes in sense of taste or smell. Therefore, the choice of medication should be discussed with a doctor and evaluated for risks and benefits on an individual basis.