Is phentermine a good option for weight loss?

Answers from Donald Hensrud, M.D.

Phentermine (Adipex-P, Suprenza) is an amphetamine-like prescription medication used to suppress appetite. It can help weight loss by decreasing your hunger or making you feel full longer. Phentermine may be recommended as part of an overall weight-loss plan if you're significantly overweight — not if you want to lose just a few pounds.

Phentermine may be a way to kick-start your weight loss. But once you stop taking it, you're likely to regain the weight you lost. That's why phentermine should be part of a plan that includes healthy eating and regular exercise — you're more likely to maintain your weight loss over time if you don't rely solely on medications.

Phentermine is a Schedule IV drug, a classification given to drugs that have a potential for abuse, although the actual potential is low. Phentermine is approved only for short-term use — 12 weeks or less. Although phentermine is one of the most commonly prescribed weight-loss medications, it has some potentially serious drawbacks. Side effects may include:

  • Increased blood pressure
  • Dizziness
  • Dry mouth
  • Sleeplessness
  • Nervousness
  • Constipation

Phentermine isn't a good option if you have certain medical conditions, including heart disease, high blood pressure, an overactive thyroid gland or glaucoma, or if you are pregnant, may become pregnant or are breast-feeding. Also phentermine shouldn't be combined with other weight-loss medications.

Oct. 22, 2011