Phentermine (phentermine hydrochloride) is a generic drug used to treat obesity. Learn about side effects, drug interactions, dosages, warnings, and more. Phentermine can be effective for weight loss when prescribed by a healthcare provider. Read about access options, precautions, and insurance coverage. Alongside a healthy diet and exercise, the drug phentermine may help you lose weight. This article explains its benefits, dosage, and possible side effects. Phentermine is used for a limited period of time to speed weight loss in overweight people who are exercising and eating a low-calorie diet. Phentermine is in a class of medications called anorectics. It works by decreasing appetite. Description Phentermine is used for weight reduction in patients with obesity. It is used in patients with obesity who have not been able to lose weight with diet and exercise alone. This medicine works by suppressing your appetite. This medicine is available only with your doctor's prescription. Phentermine is an appetite suppressant used together with diet and exercise to treat obesity. Learn about side effects, interactions and indications. Find patient medical information for Phentermine (Adipex-P, Lomaira) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings Phentermine Hydrochloride is a sympathomimetic amine anorectic indicated as a short-term adjunct (a few weeks) in a regimen of weight reduction based on exercise, behavioral modification and caloric restriction in the management of exogenous obesity for patients with an initial body mass index ≥ 30 kg/m 2, or ≥ 27 kg/m 2 in the presence of other risk factors (e.g., controlled hypertension. Phentermine is sold under many brand names and formulations worldwide, including Acxion, Adipex, Adipex-P, Duromine, Elvenir, Fastin, Ionamin, Lomaira (phentermine hydrochloride), Panbesy, Qsymia (phentermine and topiramate), Razin, Redusa, Sentis, Suprenza, and Terfamex. Phentermine is a medication used for weight management. Learn more about its mechanism of action and how well it works with GoodRx.