Phentermine is a sympathomimetic amine drug that is used as an appetite suppressant. It is prescribed for short-term treatment of obesity. Phentermine works by increasing the release of norepinephrine and dopamine in the hypothalamus, which results in decreased appetite.
Phentermine is used to treat obesity in adults. It is not effective for weight loss in children.

Phentermine is typically used for a short period of time, usually 12 weeks or less. It should not be used for more than 3 months at a time.