The Pros and Cons of Prescription Weight Loss Drugs

Want to learn about the top 3 prescribed weight loss drugs in the U.S.? Read more about how they work, what their side effects are, and how they are prescribed.

Sanaz Majd, MD
4-minute read
Episode #186

According to the Centers for Disease Control and Prevention (CDC), more than one-third of the U.S. population is obese—that means more than 78 million people. Childhood obesity is an evolving epidemic as well.Prescription Weigh Loss Drugs

This is a huge health concern because cardiovascular disease (i.e., heart attack and stroke) is the leading cause of death in both men and women in the United States. And obesity is a contributing factor to largely preventable risk factors for heart disease, such as diabetes, hypertension, and high cholesterol. Not to mention obesity is linked to other conditions, such as sleep apnea, arthritis, and cancer.

Unfortunately, there is no magic pill for weight loss. Medications are not always the solution for patients, and really shouldn’t substitute for lifestyle changes, such as instituting a nutritionally balanced diet low in fat and carbohydrates, and maintaining a long-term cardiovascular exercise regimen. A pill may help you lose weight temporarily, but what happens when it’s discontinued? These medications aren’t designed for long-term use, and if lifestyle modifications aren't implemented and maintained, then patients gain the weight right back.

With that being said, patients are very interested in learning about various options on the market. My suggestion is to consider weight loss drugs for very motivated patients—ones who have already implemented a strict weight loss and exercise plan—in order to aid them in their battle. 

So, let’s learn about the 3 most commonly used weight loss drugs in the U.S. today, including how they work, what their side effects are, and how they are prescribed. .


How it works

Your body's pancreas releases enzymes (special digestion proteins) when you consume fatty foods. These enzymes help digest fat so that it can then be absorbed from the gut into the blood stream. Orlistat prevents these pancreatic enzymes from doing their job. Therefore, since fat doesn't get digested, it can't be absorbed and is then instead excreted into the stool.

Side effects

·         The greatest causes for intolerance among patients taking Orlistat are gastrointestinal in nature—flatulence, abdominal cramping, bloating, etc.—and can occur in up to one-third of patients. But these side effects tend to improve over time with the addition of maintaining a low fat diet (less than 30% fat intake).

·         Because it prevents fat absorption, Orlistat causes some of those important fat-soluble vitamins our bodies need also to not get absorbed, such as Vitamin A, D, E, and K. Therefore, patients are often advised to take a multivitamin supplement containing these vitamins every night.

·         Orlistat also carries a small risk of kidney injury when taken by those with a history of calcium oxalate kidney stones. It shouldn’t be taken by patients with a history of these particular stones.

·         Interestingly, Orlistat has been shown to both improve blood pressure and cholesterol as added benefits.

How it's prescribed

Orlistat is available in 2 forms in the U.S., as a lower dose 60 mg over-the-counter capsule called Alli, or as a prescription 120 mg version called Xenical. It’s often prescribed as 120 mg to be taken 3 times a day.


Please note that all content here is strictly for informational purposes only. This content does not substitute any medical advice, and does not replace any medical judgment or reasoning by your own personal health provider. Please always seek a licensed physician in your area regarding all health related questions and issues.

About the Author

Sanaz Majd, MD

Dr. Sanaz Majd is a board-certified Family Medicine physician who graduated from Drexel University College of Medicine in Philadelphia. Her special interests are women's health and patient education.