Prescription Weight Loss Drugs: Do They Work? Best Options In 2024


Reviewed by Sevginur Akdas, PhD
prescription weight loss drugs
Weight loss medications can be beneficial. Photo: Caroline Ruda/Shutterstock

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Losing weight can be challenging, and it can be even more difficult to maintain weight loss. Successful weight management requires you to make changes to your diet and exercise habits, which isn’t always easy.

Fortunately, there are FDA-approved weight loss medications that can make the process less challenging. These medications aren’t magic weight loss pills, but they can support healthy weight loss.

Used alongside a healthy diet and exercise routine, prescription weight loss drugs can help you reduce your BMI. Below, we’ll discuss some of the top options, including Ozempic pills. While Ozempic, a brand-name version of semaglutide, is the most effective, there are other options.

What Is Prescription Weight Loss Medication?

  • Prescription weight loss drugs can make it easier to lose weight, but they are not magic pills.
  • Weight loss drugs can reduce appetite and block fat absorption to promote weight loss.
  • There are a variety of different weight loss drugs on the market, some more effective than others.
  • Weight loss drugs are prescribed to people with a BMI of 30 or above. People with a BMI of at least 27 may be prescribed these medications if they have a weight-related health condition. 
  • Diet and exercise are still important, even when taking weight loss drugs.

Prescription Weight Loss Drugs

Prescription weight loss drugs are medications[1] designed to manage excess weight and obesity. Excess body weight can cause serious health problems, so medications that help with weight loss are essential.

The various weight loss drugs on the market have different mechanisms of action. Some weight loss medications work by helping people to feel full sooner. Others make it difficult for the body to absorb fat from food.

When used under the direction of a doctor, these medications can be part of a chronic weight management plan. These medications work best[1] when combined with lifestyle changes and are not a substitute for diet and exercise.

The FDA approves drugs for use in patients with obesity when research determines they are safe and effective. Many of the drugs discussed below are FDA-approved specifically for weight management. However, some are approved for other purposes but used off-label for weight loss.

Best Prescription Weight Loss Pills

Best Prescription Weight Loss Pills
Weight loss prescription medications can reduce appetite. Photo: New Africa/Shutterstock

There are numerous prescription medications designed to help with weight management. They can help you lose weight and reduce body fat in combination with diet and physical activity. These medications are described in more detail below. 


Ozempic is a brand-name version of the drug semaglutide. This prescription weight loss medication is also sold under the brand name Wegovy. In June 2021, semaglutide[2] was FDA-approved for chronic weight management among patients with obesity-related health conditions. 

For example, patients who have weight-related conditions like high blood pressure or type 2 diabetes can take semaglutide. A recent randomized clinical trial[3] found that subcutaneous semaglutide was effective for weight loss. 

Patients in the above study also participated in counseling and followed a low-calorie diet. This demonstrates that lifestyle changes are critical when taking this weight-loss medicine. 

Semaglutide is one of the best weight loss drugs because it affects areas of the brain responsible for appetite regulation.[1] Studies have shown that it is superior to other weight loss drugs.[4] Average weight loss over 68 weeks is 15%[4] of initial body weight. 

If you ask what the strongest weight loss prescription pill is, Ozempic is probably the best answer. Its active drug, semaglutide,[4] has shown superiority over other anti-obesity medications. However, people who stop taking this drug regain two-thirds[5] of their lost weight a year after discontinuing it.


Also among the weight loss pills that work is Contrave. This brand-name weight loss drug contains naltrexone and bupropion.[6] This combination is believed to increase satiety, reduce food intake, and increase energy expenditure.

Bupropion is a medication used to treat depression, but in combination with naltrexone, it reduces food intake.[6] As is true with other weight loss drugs, it should be used in combination with exercise and a low-calorie diet.

Naltrexone[7] is most commonly used to treat alcohol and opioid addiction. However, it can also decrease cravings, and it works synergistically with bupropion.

Contrave[6] is beneficial for patients who have a body mass index or BMI of 30 or above, which indicates obesity. It is also used in those with a BMI of 27 or above if they have weight-related health problems. This could include high blood pressure or elevated cholesterol. 


If you’re looking for a fat burner, try Orlistat instead. This medication works by reducing fat absorption by up to 30%.[8] Studies have also shown that Orlistat reduces body mass index and body weight more effectively than diet alone.

Orlistat can also address weight-related health problems. Patients taking[8] Orlistat experience reductions in LDL cholesterol, fasting blood sugar, and systolic blood pressure.

Many patients lose 5%[8] or more of their body weight using orlistat. This medication is also beneficial for cardiovascular health, so it can prevent heart disease.

You may not need a prescription to obtain orlistat. Low doses of the drug are available over-the-counter.[7]


Sold under the brand name Qsymia, this combination medication[8] helps people lose weight. Phentermine works as an appetite suppressant, while topiramate causes decreased appetite and increased feelings of fullness.

Topiramate is typically used to treat migraine headaches and epilepsy. However, it is FDA-approved to treat obesity in combination with phentermine.

Studies have shown that phentermine/topiramate[8] is significantly more effective than placebo for inducing weight loss. One study found that people lost an average of 7.97%[9] of their body weight with phentermine/topiramate.


Liraglutide belongs to the same medication class as semaglutide. Like semaglutide, liraglutide is administered subcutaneously. 

This medication has been found to cause meaningful weight loss. In fact, 63%[10] of patients who take liraglutide achieve 5% weight loss. Patients taking liraglutide lose 5.3 kg[10] more after one year than those taking a placebo. 

Liraglutide is especially beneficial for obesity treatment in patients with type 2 diabetes. It helps with blood sugar control[8] and can be used as an add-on to insulin. 

While approved by the FDA for weight loss, liraglutide is not as effective as semaglutide. One study found patients taking liraglutide lost 5.4%[11] of body weight, compared to 12.4%[11] in patients on semaglutide. 

Another drawback of liraglutide is that it is a daily injection. This means you’ll need to decide the best time to take it and make it part of your daily routine. 


Metformin is FDA-approved[12] to treat type 2 diabetes. Along with lifestyle changes like diet and exercise, this medication reduces blood sugar levels. Studies show that patients taking metformin[13] lose modest amounts of weight over time. 

Patients who take metformin can expect to lose 3.5%[13] of body weight. This medication can also reduce the risk of diabetes in those with risk factors. While it is not specifically approved for weight loss, doctors may use metformin off-label[14] for obesity. 


Setmelanotide[1] is a unique medication, used to reduce body weight in patients with any of three specific rare genetic disorders. This medication does not treat genetic problems, but it can lead to weight loss in patients with obesity. 

Setmelanotide[1] can reduce appetite and increase resting metabolism. This can be helpful for people who have birth defects that affect appetite and metabolism. 

Variations in genes that affect a pathway associated with body weight regulation can cause obesity. However, setmelanotide[15] can reduce hunger so that people with these genetic defects can lose weight. 


Marketed under the brand name Byetta, exenatide is FDA-approved[16] for treating type 2 diabetes. Some doctors may also use it off-label to treat overweight and obesity.  

In one study, people reduced their food intake when taking exenatide.[17] The study authors concluded that this medication is effective in reducing the risk of weight gain after a period of weight loss. 

In patients with newly diagnosed type 2 diabetes, exenatide is superior to metfơormin[18] for weight loss. So, while exenatide may not be a weight loss drug, it is an option doctors may consider for treating obesity. 

How Effective Are Prescription Weight Loss Drugs?

The effectiveness of prescription medications for weight loss varies. 

A review of all the research on weight loss prescription drugs[8] found that these drugs do induce weight loss. Among various drugs, including orlistat, phentermine/topiramate, naltrexone/bupropion, and liraglutide, semaglutide[8] appears to be the most effective. However, all of these drugs have been shown to help patients lose weight.  

Research with semaglutide has found that patients can lose as much as 16%[3] of their body weight over 68 weeks. After 12 weeks, patients taking naltrexone/bupropion have lost 2.66%[19] of body weight. Patients taking phentermine/topiramate have lost 3.63%[19] of body weight over 12 weeks. 

A seven-month study found that patients taking liraglutide lost an average of 7.7 kg.[8] Those taking orlistat lost 3.3 kg,[8] on average. 

While semaglutide seems to be the most effective of the weight loss medications, it does come with side effects. For example, gastrointestinal side effects[3] are common with semaglutide. Some patients may prefer other medications because they cause fewer or less severe side effects. 

Weight loss drugs can be effective, but lifestyle changes remain the most important factor for maintaining weight loss. You can regain weight[5] after stopping medications, so you must change your habits related to food and exercise. If you’re struggling, a therapist, dietician, or support group can be helpful. 

Who Can Take Weight-Loss Drugs?

Who Can Take Weight-Loss Drugs
Weight loss drugs are prescribed to those who are obese/overweight. Photo: Pixel-Shot/Shutterstock

Some people are good candidates for weight loss medications, and others are not. People who want to improve their health can take weight loss medications if the benefits outweigh the risks.

These medications shouldn’t be taken just to improve appearance. Instead, they should be used as part of a healthy lifestyle to reduce health risks like elevated blood pressure. Obesity and  excess weight can cause health problems, and weight loss medications are ultimately used to improve health.

Doctors generally prescribe weight loss pills to those with a BMI of 30[1] or above. Weight loss medications are also used in those with a BMI of 27[1] or higher and co-occurring health problems. A doctor can help you determine if weight loss drugs are suitable for you.

Lifestyle changes, including exercise and a healthy eating plan, are the first line of treatment for obesity. If these changes are not successful, a doctor may add medications[7] to a patient’s treatment plan. Patients typically must try diet and exercise for 12 months without success before medications are added.

Can Children Take Weight-Loss Drugs?

Children who are obese are also at risk of negative health outcomes,[20] including type 2 diabetes, breathing problems, and heart disease. Therefore, it is important to treat obesity in children. About 6.1%[21] of children have severe obesity and need intensive weight loss interventions.

Children and teens[22] who do not respond to lifestyle modifications alone may benefit from medications. Some of these medications are safe and approved for children and adolescents. The following medications[1] can be used in those aged 12 and up.

  • Orlistat.
  • Phentermine/topiramate.
  • Liraglutide.
  • Semaglutide.

Pediatric patients aged six and older can take setmelanotide[1] to treat obesity arising from genetic disorders. In some cases, metformin[22] may be used off-label in pediatric patients. In clinical trials,[23] metformin has been safely administered to children as young as six years old. 

Do Weight Loss Pills Work?

There is a large body of research[8] that shows weight loss medications are effective. Patients who use these medications tend to lose weight. However, total weight loơss can vary based on the specific drug used. 

It is also important to remember that these medications are not a substitute[1] for diet and exercise. If you do not change your diet or prioritize exercise, you will not lose weight, even with medications. Also, remember that you can regain the weight you’ve lost after you stop medications. 

It’s still important to maintain a calorie deficit while taking diet pills. This means you’ll need to figure out how many calories you need to lose weight. Try an online calculator[24] if you’re not sure. 

Also, remember that weight loss medications don’t work for everyone. A specific medication may work for some people but not others. You might have to try several medications before finding one that works for you. 

Are Weight Loss Pills Safe?

If a doctor prescribes a prescription weight loss medication, it is because they believe its benefits outweigh its risks. Obesity can come with serious health problems, and some people may need weight management medications to lose weight.

While these medications can be effective, they are not without side effects. Common side effects[25] include vitamin deficiencies, nausea, vomiting, constipation, insomnia, dizziness, and headache. These side effects can vary based on the medication, and some weight loss pills can even cause oily stools. 

Many weight loss medications are FDA-approved, and they are safe to use with a doctor’s recommendation. However, it is important to ensure that the risk of side effects is outweighed by the benefits a medication provides. 

Some medications, such as metformin, are not approved by the FDA to treat overweight and obesity. These medications may come with serious risks,[14] including abdominal pain, pancreatitis, hepatitis, and reactive hypoglycemia. It’s essential to ask your doctor about any risks that come with medication. 


There are a variety of weight loss medications on the market. They are used when people have a high BMI and/or weight-related health conditions like high cholesterol.

Anti-obesity medications are not a cure-all for weight problems. However, when combined with diet and exercise, they can make it easier to lose weight. For people with a high BMI, medications can lead to significant weight loss and improved health. 

You may benefit from taking medication to help you lose weight, in combination with a reduced-calorie diet. Your doctor can help you decide which medication, if any, is most appropriate for you. 

If your doctor prescribes one of these medications, they can reduce appetite and cravings to make it easier to stick to a diet. Over time, this can lead to successful weight loss, even when past diets have failed. 

Despite the effectiveness of weight loss drugs, it’s important to make lasting lifestyle changes for long-term results.  It is helpful to seek support groups or engage in therapy to learn tools for making changes related to food. 

Frequently Asked Questions

What is the most effective weight loss prescription?

There are various weight reduction medications on the market. Studies have shown that semaglutide,[4] sold under brand names Ozempic and Wegovy, results in the most weight loss. 

Will I gain weight after stopping Ozempic?

You could regain weight after stopping Ozempic. One study found that in the year following Ozempic discontinuation, people regained two-thirds[5] of lost weight.

How much weight can you lose on Ozempic in a month?

Ozempic is not meant to cause fast weight loss, so you shouldn’t worry about one-month weight loss. Research with Ozempic has found that average weight loss after three months is 6.7 kg.[26]

What BMI is needed for Ozempic?

Most anti-obesity medications,[1] including Ozempic, are prescribed to those with a BMI of 30 or above. People who have a BMI of 27 or above may be prescribed Ozempic if they have weight-related health problems. 

What happens if you eat sugar while taking Ozempic?

Too much added sugar can cause you to exceed your daily calorie intake. Patients in clinical studies with Ozempic are instructed to maintain a deficit of 500 calories daily.[27] If you eat too much sugar, you might not lose weight.

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EHproject has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We work mostly with peer-reviewed studies to ensure accurate information. We avoid using tertiary references. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.

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Jennifer Jacobsen is a university professor and mental health professional with over 10 years of experience writing in the health and wellness space. See More