Phentermine Side Effects
Hyperactivity, insomnia, dry mouth, and dizziness are some of the side effects that have been reported with phentermine. In most cases, problems usually occur when too much of the medication is taken. Other, less-frequent side effects of phentermine are potentially serious and should be reported to a healthcare provider right away. These include hallucinations, high blood pressure, and a rapid heart rate, among others.
As with any medicine, side effects are possible with phentermine; however, not everyone who takes the medication will have problems. In fact, most people tolerate it quite well. In most cases, side effects occur when too much phentermine is taken.
(This article covers many, but not all, of the possible side effects with phentermine. Your healthcare provider can discuss a more complete list of side effects with you.)
Phentermine has been studied thoroughly in clinical trials. In these studies, the side effects that occur in a group of people taking the drug are documented and are then compared to side effects that occur in another group of people not taking the medicine. This way, it is possible to see what side effects occur, how often they appear, and how they compare to the group not taking the medicine.
With newer medications, information about the exact percentages for these side effects are available. However, with older medications (such as phentermine), these statistics are not available.
In studies, phentermine side effects included:
- Insomnia (see Phentermine and Insomnia)
- Unusual happy feelings (euphoria)
- Unusual unpleasant feelings (dysphoria)
- Shakiness (tremor)
- Dry mouth (see Phentermine and Dry Mouth)
- Unpleasant taste
- Sexual problems (see Phentermine Sexual Side Effects).