If you've been trying to lose weight for a while, you may be tempted to buy an over-the-counter diet pill or ask your doctor for a prescription. While some remedies are indeed effective, all diet pills carry some health risks, warns the Mayo Clinic. Generally, the most effective diet pills are only available with a doctor's prescription. While medical research does not point out any diet pill that is better for women than for men, pregnant women, nursing women and women with medical problems such as high blood pressure or autoimmune diseases should not take any type of diet pill.
Phentermine is a prescription appetite suppressant that is the most commonly prescribed diet pill in the United States, according to the National Institute of Diabetes and Digestive and Kidney Diseases. Doctors first started prescribing this amphetamine-like pill in 1959. But phentermine, commonly marketed as Adipex, carries the risk of side effects such as increased blood pressure, sleeping problems and anxiety. Also, representatives of the Food and Drug Administration have only approved phentermine for short-term use of 12 weeks or less.
Xenical is another popular prescription diet aid, but this pill blocks the digestion of fat and does not affect the appetite, according to the Mayo Clinic. Each Xenical pill contains 120 mg of orlistat; people who eat high fat meals may experience unpleasant side effects such as uncontrollable bowel movements, oily spotting and stomach pain. People taking Xenical as directed can expect to lose five to seven pounds more than they would have by just relying on diet and exercise.
Alli is one of the few over-the-counter diet aids that might actually work, according to the Mayo Clinic. The pill is a lower-dosage version of Xenical, consisting of 60 mg of the fat-blocking drug orlistat. But representatives of the Food and Drug Administration have investigated user claims that Alli causes serious liver injury in rare cases; if you experience jaundice or dark-colored urine while using any dosage of orlistat you should consult a doctor immediately. People who take Alli as instructed, exercise regularly and change their eating habits usually lose three to five pounds more than they would have without diet pills. (References 1 and 4)
Diethylpropion and Phendimetrazine
Diethylpropion and phendimetrazine are effective prescription appetite suppressants and considered generally safe, according to the National Institute of Diabetes and Digestive and Kidney Diseases. But these suppressants, as with phentermine, are not for long-term use. Also, potential side effects include dizziness, headaches, sleeping problems and nervousness. These medications decrease the appetite and help improve mood in adults who use them as directed.
- Mayo Clinic: Over-the-Counter Weight-Loss Pills
- Weight-control Information Network; Prescription Medications for the Treatment of Obesity; December 2010
- Mayo Clinic: Phentermine - Can Prescription Medication Help Weight Loss?; Donald Hensrud; October 2009
- Mayo Clinic: Alli Weight-Loss Pill - Does It Work?
- PubMed Health: Orlistat