Phentermine is a prescription weight loss medication that is approved by the US Food and Drug Administration (FDA). It is a sympathomimetic amine that works by suppressing appetite and increasing metabolism, thereby helping to reduce food intake and promote weight loss.

Phentermine is typically prescribed for short-term use, and it is important to take the medication exactly as prescribed by a healthcare provider. It is usually taken orally in tablet or capsule form, and it is often combined with other weight loss medications, such as topiramate, to enhance its effectiveness.