Adipex works on the central nervous system to suppress the appetite. As a stimulant, it works in a similar way as amphetamine drugs and can have similar side effects. It is the similarity between Phentermine and amphetamines that lead many people to experience the increased energy and difficulty sleeping that are common side effects of taking this diet pill. The increased energy that is common for Phentermine users can help with weight loss, as many people find it easier to start or maintain an exercise program while taking them.
Adipex is available as a 37.5-mg capsule and a 30-mg capsule. The 30-mg capsule is sold under the name Fastin. Generic Phentermine is available in both dosages as well. Most doctors will prescribe the less expensive generic form of this pill. If you have concerns about the effectiveness of Phentermine compared to Adipex, talk to your physician when he writes your prescription. Some doctors prescribe Prozac, an antidepressant, along with Phentermine. If you have never taken Prozac before, you may want to talk to your doctor about starting with only one or the other, so that if one of the medications does not agree with you, it is easy to determine the problem.