Adipex-P is a brand name in the United States for the generically named drug phentermine. It is a prescription-level medication used to help suppress your appetite to help you get started reducing your bodily weight. The Mayo Clinic reports that medical appetite suppressants generally only work for most people for a few weeks, so it typically is prescribed along with a regimen of dieting.
Sexual Side Effects
Taking Adipex-P can induce temporary alterations of your sexual activities. In men, for example, it can make it difficult to get an erection—even with stimulation—or make it difficult to keep erect. It also may have the effect of changing your normal sexual drive. This could mean more interest in having sex than usual or having less interest. These common side effects are categorized as non-serious and typically vanish in a few days after first taking Adipex-P. Tell a physician if you do not see them disappear.
Because Adipex-P is a stimulant, it can make it hard for you to get to sleep, Drugs.com reports. This should change as your body gets used to the medicine. You generally can avoid the problem by taking the medication early in the day. The Mayo Clinic recommends taking it either directly before breakfast or up to two hours later.
Phentermine can temporarily make you feel euphoric. This means everything seems great—even if it is not—all the time. You may feel better than you have previously, but the effect is an exaggeration of mood, not a long-term condition. In any event, this euphoria typically passes in a few days. Tell your physician if it does not.
Diarrhea and Constipation
Most stimulants can cause some temporary changes in the way your digestive system functions. When you begin taking it, Adipex-P may cause your digestive system to leave extra liquid in your stools, making you have diarrhea. Cramps may be associated with diarrhea. The opposite effect also may take place--you may become constipated and find it difficult to move your bowels, despite a sensation that you need to do so.