What’s the Best Weight Loss Medication?

By Terez Malka, MD
Medically reviewed checkmarkMedically reviewed
December 7, 2022

Currently, ten medications are approved by the Food and Drug Administration (FDA) for weight loss. Six of these medications are approved for long-term use. Some of these medications are available as weight loss pills that can be taken orally, while others are available as injections. 

All the weight loss medications approved by the FDA have their unique risks and possible benefits. Identifying the best one for your needs requires a consultation with your healthcare provider.

Keep in mind that one of these medications on the market may be right for you, depending on your medical history and current health. 

Prescription Weight Loss Medications

When used alongside behavioral modifications, including a diet and physical exercise program, prescription weight loss medications can help certain individuals to lose weight.

If you’re interested in taking weight loss medication, it’s important to speak with your healthcare provider about the option that is the right fit for you.

Who is a candidate for weight loss drugs?

FDA-approved weight loss drugs are indicated for use in individuals with obesity. In most cases, the BMI threshold for these drugs is 30 or higher.

Certain drugs can also be used in individuals with a BMI of 27 or higher if they also have a certain health condition, like type 2 diabetes or high blood pressure. Most medications are only approved for use in adults, but some may be approved for use in certain children and adolescents.

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How effective are weight loss drugs?

Drugs that have gained approval from the FDA as weight loss medications have undergone trials demonstrating their efficacy in helping people to lose weight. But it’s important to note that these medications can pose serious risks to your health and may not be right for you.

That is why speaking to your healthcare provider is important if you’re considering taking weight loss medication. 

What Drugs are Approved For Weight Loss?

There are several drugs approved by the Food and Drug Administration (FDA) for weight loss. 

Naltrexone-bupropion

Naltrexone-bupropion, sold under the brand name Contrave, is a mix of two medications. The first, naltrexone, is an opioid receptor antagonist used to treat alcohol and drug dependence.

The second, bupropion, is a dopamine and norepinephrine reuptake inhibitor used to treat depression and help people quit smoking. Together, the two medications are indicated for chronic weight management when used alongside a reduced-calorie diet and a physical exercise program in people over a certain BMI.

Unfortunately, a significant proportion of people who take this medication will experience side effects, which can include gastrointestinal symptoms, depression, high blood pressure, seizures, and suicidal behavior.

Liraglutide

Liraglutide is a glucagon-like peptide-1s receptor agonist (GLP-1) medication. It first gained approval from the FDA in 2010 as an adjunct therapy to diet and exercise for the management of type 2 diabetes, sold under the brand name Victoza. 

In 2017, a higher dose of liraglutide sold under the name, Saxenda gained approval as a weight loss medication. Liraglutide supports weight loss by improving insulin production in the pancreas, slowing down the rate of stomach emptying, and stabilizing glucose and insulin levels after eating.

Orlistat

Orlistat (sold under the brand names Xenical and Alli) is a weight loss pill intended to be used alongside a low-calorie, low-fat diet and exercise program. It’s a type of medication called lipase inhibitor, which works by reducing the amount of fat your body absorbs from the food you consume.

Because of this, it’s important to evenly divide the amount of fat, carbohydrates, and protein you consume in one day. 

If you take the medication when eating a high-fat diet, you’re more likely to experience side effects, including changes in bowel movement habits, oily spotting, loose stools, oily or fatty stools, pain, or discomfort in the rectum, stomach pain, and irregular menstrual periods

Phentermine-topiramate

Phentermine-topiramate, sold under the brand name Qsymia, is a combination of two medications: phentermine and topiramate. Phentermine is a stimulant similar to amphetamine which reduces appetite, and topiramate is a medication used to treat seizures or migraine headaches

Mild side effects, including dry mouth, constipation, and tingling sensations, are possible when taking this medication. But more serious effects are also possible, including an increased resting heart rate, central nervous system depression, acute myopia, hypoglycemia, and psychiatric and cognitive disturbances.

For these reasons, anyone taking the medication should be closely monitored by their health care provider.

Semaglutide

Semaglutide is a glucagon-like peptide-1s receptor agonist (GLP-1) medication. It was first approved in 2017 under the brand name, Ozempic as a treatment for type 2 diabetes.

But in 2021, a higher dose of semaglutide marketed under the name Wegovy was approved by the FDA for weight loss. It was the first new weight loss medication to gain approval by the FDA in several years. Semaglutide is available only as an injection.

Like most weight loss medications, Wegovy is intended for use in combination with behavioral modifications, including diet and exercise changes recommended by a healthcare provider. Side effects are possible, but most are mild and affect the gastrointestinal system, including nausea, constipation, and stomach pain.

Wegovy isn’t right for everyone and can only be prescribed for people who meet certain criteria, including having a BMI of 30 or higher or a BMI of 27 and higher in addition to a metabolic health condition, like type 2 diabetes. 

Others

The FDA approved four other medications for short-term use (up to 12 weeks) for weight loss. These prescription drugs include phentermine, benzphetamine, diethylpropion, and phendimetrazine. 

These drugs are stimulants similar to amphetamines and work by increasing chemicals in the brain to suppress your appetite. However, these drugs can cause harmful and sometimes life-threatening side effects. 

They can also be habit forming, which is why it’s important to take these medications exactly as prescribed and never to share them with another person.

Do Weight Loss Medications Work?

Weight loss medications approved by the FDA have undergone trials to demonstrate their efficacy in helping people to lose weight. Each medication may work best for certain individuals depending on their health history, weight, and other medical conditions.

Your healthcare provider can help you decide if a weight loss medication is a good option for you.

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How Long Do Weight Loss Medications Take to Work?

When combined with diet, exercise, and other lifestyle modifications (like stress management and sleep hygiene), most weight loss will take place within the first six months of starting medication. Your healthcare provider should monitor your health and progress while on weight loss medication.

In some cases, if you haven’t achieved 5% weight loss within three months of starting medication, your provider may recommend a change in dose, changing or discontinuing the medication. 

It’s important to note that maintaining weight loss can be more challenging than losing weight.

In order to sustain weight loss achieved through the use of prescription medication and behavioral changes, your provider may recommend staying on medication in addition to sustaining your behavioral modifications over the course of your life.

Which Weight Loss Medication Is Best?

There is no single best weight loss medication. The right option depends on your specific needs, health history, lifestyle, and other medical conditions.

Asking Your Provider About Weight Loss Drugs

When used alongside lifestyle modifications, weight loss drugs can help certain individuals lose weight and keep it off. 

If you’re interested in taking weight loss medication, you can see if you’re a good fit for K Health’s online medical weight loss program.

Frequently Asked Questions

What is the most effective medication for weight loss?
There are several weight loss medications approved by the FDA. Which medication will be most effective for you depends on several factors, including your medical history and health goals. Each medication has its own potential risks and benefits, so it’s important to speak with your provider about whether any of these medications is right for you.
Are there medications that make you lose weight fast?
There are several weight loss medications approved by the FDA for short-term use. These include phentermine, benzphetamine, diethylpropion, and phendimetrazine. Because these drugs are stimulants, they can cause harmful and sometimes life-threatening side effects. They can also be habit-forming, which is why they’re only intended for short-term use. If your provider prescribes one of these medications for you, it’s important to take them exactly as directed and never to share them with another person.

K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Terez Malka, MD

Dr. Terez Malka is a board-certified pediatrician and emergency medicine physician.

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