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Why you should skip weight loss drugs

Medications promise to help drop pounds, but at the risk of potentially serious side effects.

Published: December 31, 2014 09:00 AM

Like weight-loss supplements and weight-loss surgery, prescription and over the counter weight- loss drugs offer the promise of an easy fix for people struggling to shed pounds. Just last week, yet another weight-loss drug, Saxenda, was approved by the U.S. Food and Drug Administration, bringing the number of FDA-approved weight loss drugs to five.

Given the imminent arrival on the market of Saxenda, we thought it was a good moment to give our verdict on the various weight-loss drugs on the market.

All of the weight loss medications are only indicated for people who are obese (with a BMI of 30 or greater), or those who have a BMI of 27 to plus plus a weight-related health condition such as diabetes.  

Alli/Xenical (orlistat)

Year approved: Xenical, 1999; Alli, 2007

How it works: In both of its forms—over the counter (Alli) and prescription (Xenical)—orlistat works by blocking the enzyme that allows you to digest and absorb dietary fat. After a voluntary recall last March (the manufacturer suspected tampering after consumers reported bottles containing tablets in various shapes and colors), Alli is expected to return to stores in the first half of 2015.

Typical results: In clinical trials, after a year of treatment with orlistat, severely overweight patients on a reduced-calorie diet lost 7 pounds more than those who took a placebo.

Side effects: Orlistat has been linked, on rare occasions, to severe liver damage, liver failure (resulting in a transplant), and even death. Last summer the manufacturer added a new warning to the label, noting that the drug might interfere with the absorption of antiseizure and other medications. Orlistat may decrease the absorption of vitamins A, D, E, and K. Other side effects include gas and involuntary discharge of stool.

Belviq (lorcaserin)

Year approved: 2012

How it works: This medication promotes weight loss by activating brain receptors for serotonin, a neurotransmit­ter that triggers feelings of fullness.

Typical results: After a year, those taking lorcaserin lost only 6 pounds more than those who took a placebo. After another year, participants gained back about a quarter of the weight they had lost. Some had trouble trouble staying on the drug due to side effects.

Side effects: The drug can cause headaches, dizziness, fatigue, nausea, constipation, memory and attention problems, and (rarely) a leaky heart valve. As a result, the FDA has required the manufacturer to conduct studies to rule out heart problems. Like many prescriptions, Belviq can also interact dangerously with other drugs. If you take it with antidepressants or a migraine medication, for example, you can develop serotonin syndrome, which is characterized by agitation, diarrhea, a fast heart rate, and hallucinations.

Qsymia (phentermine/topiramate)

Year approved: 2012

How it works: This drug is a combination of two prescription medications—the stimulant phen­termine, which suppresses appetite, and the antiseizure drug topiramate, which sometimes causes weight loss as a side effect.

Typical results: Qsymia may lead to more weight loss than the other medications, though the benefits are still fairly modest. After a year of taking the drugs, 7 percent more people taking the drug lost at least 10 percent of their body weight compared to those who took a placebo. 

Side effects: Increased heart rate and memory, attention, or speech problems may occur. Also, anxiety, insomnia, and depression (including suicidal thoughts). About 40 percent of people in clinical trials stopped taking Qsymia. To ensure that it doesn’t cause cardiovascular problems, the FDA has the manufacturer to conduct a postmarket study.

Contrave (naltrexone/bupropion)

Year approved: 2014

How it works: This combination of naltrexone (an medicine usually used to treat alcohol and opioid addiciton) and bupropion (an antidepressant) may reduce appetite and curb cravings.

Typical results: After a year on the drug, nondiabetic patients in a clinical trial lost 4.1 percent more weight than those who took a placebo.

Side effects: Nausea, consti­pa­tion, headache, vomiting, dizziness, insomnia, dry mouth, and diarrhea are the most common side effects. More troubling, the drug may cause seizures. And because it contains the antidepressant bupropion, it must carry a boxed warning saying that it might increase sui­ci­dal thoughts and behavior. The FDA is concerned about the medication’s effect on the heart and is requiring more studies.

Saxenda (liraglutide)

Year approved: 2014

How it works: It decreases hunger and increases feelings of fullness. The injectable drug is now sold in a lower dose as Victoza, a medicine used to treat type 2 diabetes.

Typical results: In clinical trials, about 60 percent of patients taking Saxenda lost at least 5 percent of their weight, compared with 24 percent of people on a placebo.

Side effects: Nausea, vomiting, and diarrhea. It was found to cause thyroid tumors in animals, so Victoza’s label has a warning. It can also cause inflammation of the pancreas and an increased risk of pancreatic cancer and gallstones, and a risk of suicidal thoughts.

CR’s take:

None of the drugs listed above reliably lead to impressive weight loss. And they can all cause serious side effects. So we recommend skipping these weight loss drugs and sticking with calorie reduction and exercise to drop pounds.

The best way to lose weight

Despite the dizzying array of diets out there, losing weight is actually pretty simple. In a 2014 analysis of 48 diets published in The Journal of the American Medical Associ­ation, participants achieved significant weight loss by following any low fat or low carbohydrate diet. Here are a few tips:


• Pick a reasonable goal. Studies and surveys have found that an initial weight loss goal of 5 percent is realistic and offers important health benefits, including reduced blood cholesterol and glucose levels, and a lowering of blood pressure, to name just a few.


• Portion control is key. Aim to consume fewer than 2,000 calories per day—ideally around 1,200 to 1,500 per day for women and 1,500 to 1,800 for men.


• Cook and eat at home, where you have more control over calories you take in.


• Eat more fruit and vegetables, choose whole over refined grains, and select lean meats and seafood.


• Eat a protein rich breakfast.


• Reduce your sugar intake to 10 percent (or less) of your total daily calories.


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