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. Phentermine is an appetite suppressant used together with diet and exercise to treat obesity. Learn about side effects, interactions and indications. 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. 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] About phentermine Phentermine (Adipex-P) is an inexpensive drug used to decrease appetite. It is used with a reduced calorie diet and exercise to help you lose weight. It is more popular than comparable drugs. It is available in generic and brand versions. 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 (phentermine hydrochloride) is a generic drug used to treat obesity. Learn about side effects, drug interactions, dosages, warnings, and more. Easy-to-read patient tips for phentermine covering how it works, benefits, risks, and best practices. Phentermine (Adipex-P, Lomaira) is a prescription medicine used to lessen appetite. It can help weight loss by making you less hungry. Or it can help you feel full longer. Phentermine also is offered combined with topiramate for weight loss (Qsymia). The combined drug is approved for long-term use. Phentermine is approved for use for up to 12.