Phentermine is a prescription appetite suppressant used for the short-term treatment of obesity. It works by decreasing appetite and increasing energy expenditure, helping individuals lose weight when combined with a reduced-calorie diet and exercise program. Buying Phentermine online may offer convenience for individuals seeking to manage their weight, but it's essential to use it under the supervision of a healthcare professional. Phentermine can cause side effects such as increased heart rate, insomnia, and dry mouth, and it's not suitable for long-term use due to the risk of dependence and tolerance.