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 weeks. But weight management can take time. So some health care providers might order it for longer use.
Like other weight-loss medicines ordered by providers, phentermine is meant to be only part of a weight-loss plan. For example, it can be be used with healthy eating, physical activity and behavior change. Phentermine is for people with obesity or overweight who haven't been able to lose enough weight with diet and exercise alone to improve their health.