Phentermine is a medication that is prescribed to obese people in hopes to help them lose weight. This medicine works especially well when a patient is following a diet and exercise plan. The way this medication works is by decreasing the persons appetite so they will not feel the need to eat all of the time. Side effects of Phentermine: Nausea Vomiting Diarrhea Dry mouth Constipation High blood pressure Increased heart rate Hyperactivity Insomnia Depression Drowsiness Many of the side effects listed above do not take place with patients who follow the instructions given by their doctors correctly. However, if the side effects do occur and they do not go away in a few days you should express your concerns with your physician. Also if you use the medication for an extended amount of time your body may come physically and psychologically dependant on it so when it is time for you to stop using the medication you may experience some of the following withdrawal symptoms: Excessive drowsiness Fatigue Depression or suicidal thoughts Tremors What is the usual amount of time Phentermine is used? Phentermine is usually used for a short amount of time. More specifically it can be used from anywhere from three weeks up to six weeks. The length of time that one will need to use it is going to vary for each person because each persons body is going to respond differently to the medication. However, before you begin taking this medication make sure that your doctor knows if you are taking any other medications and also whether or not you are nursing, pregnant or planning to become pregnant. If something is prohibiting you from taking this medication he/she will be able to give you something else that will work. Phentermine no prescription