Qsymia is a prescription medicine that contains phentermine and topiramate extended-release. Qsymia may help adults and children 12 years and older with obesity, or some adults with overweight who also have weight-related medical problems, to help them lose excess body weight and keep the weight off. Qsymia should be used with a reduced calorie diet and increased physical activity. It is not known if Qsymia changes your risk of heart problems or stroke or of death due to heart problems or stroke. It is not known if Qsymia is safe and effective when taken with other prescription and over-the-counter medicines, or herbal weight loss products. It is not known if Qsymia is safe and effective in children under 12 years old.