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. Phentermine, sold under the brand name Adipex-P among others, is a medication used together with diet and exercise to treat obesity. [3] It is available by itself or as the combination phentermine/topiramate. [8] Phentermine is a medication for chronic weight management. It is for people with overweight and weight-related complications or obesity. It is meant to be used together with a lifestyle therapy regimen involving a reduced calorie diet and increased physical activity. How Does Phentermine Work? Phentermine (Adipex-P, Lomaira) is an oral weight-loss medication that works by reducing appetite. In studies, more than 80% or more of people lost at least 5% of their body weight while taking phentermine. Phentermine (Adipex-P and Lomaira) is a schedule IV controlled prescription drug used as a short-term weight loss in conjunction with diet and other lifestyle modifications to treat obesity. Phentermine is an appetite suppressant used together with diet and exercise to treat obesity. Learn about side effects, interactions and indications. Phentermine - cas 122-09-8, synthesis, structure, density, melting point, boiling point Alongside a healthy diet and exercise, the drug phentermine may help you lose weight. This article explains its benefits, dosage, and possible side effects. 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. Overview: Phentermine is used short-term to help with weight loss in people who have obesity or are overweight. Common side effects include fast heartbeat, high blood pressure, and restlessness..