As obesity rates continue to rise globally, patients and providers are turning to new treatment options to help manage weight. Weight loss can be a lifelong challenge. A healthy diet and physical activity can help. But despite adopting these lifestyle changes, many still struggle to maintain a healthy weight.

The growing market of weight loss drugs can help. Finding the best treatment for you can be challenging with so many different options. Take this article as an introduction to prescription weight loss drugs. We’ll examine common brand name medicines, how these drugs work, and what side effects they cause.

Do prescription weight loss drugs work?

Yes. Clinical trials testing prescription weight loss drugs show they are effective in helping patients lose weight.

In trial after trial, people who took weight loss drugs experienced more significant weight loss than people in the placebo group.

In the clinical trials for Zepbound (tirzepatide), people who took the drug along with lifestyle changes lost an average of 48 pounds. Those who took the lowest dose lost, on average, 34 pounds. In comparison, the people who didn't take Zepbound only lost 7 pounds.

Here’s another example: Wegovy was tested on around 4,500 people in four studies. In three of these studies, some took Wegovy, while others took a placebo. Many people who took Wegovy lost at least 5% of their body weight in 68 weeks.

In another study, those on Wegovy lost 7.9% of their body weight from week 20 to week 68, while the placebo group lost 6.9%.

These examples are just a sample of how effective weight loss drugs can be. It’s important to note that participants also went through lifestyle changes to help them lose weight. These lifestyle changes include eating a healthy diet and exercising regularly.

While prescription weight loss drugs are effective, providers don’t prescribe them on their own. The long-term use of these drugs is coupled with a reduced-calorie diet and regular physical activity. Combining medication and healthy habits is most effective in helping patients lose and keep weight off.

Who should take weight loss drugs?

Ignore the jokes about celebrities and influencers using these drugs to keep their famous frames. Prescription weight loss drugs aren’t meant to help you lose a few pounds before swimsuit season. These drugs are FDA-approved to treat overweight and obesity. They are for patients who may be at risk for severe weight-related health problems.

Overweight and obesity are determined by a person’s body mass index (BMI). It measures weight in comparison to a person’s height.

Overweight: Being overweight means having a higher body weight than what is considered healthy for a person's height. It is often defined as having a BMI between 25 and 29.9. While being overweight may not always lead to immediate health problems, it can increase the risk of various health issues, such as heart disease, diabetes, and joint problems.

Obesity: Obesity is a more severe condition characterized by excessive body fat that can have serious health consequences. It is typically defined as having a BMI of 30 or higher. Obesity significantly raises the risk of chronic diseases like heart disease, high blood pressure, type 2 diabetes, certain cancers, and sleep apnea.

It's important to note that BMI is a useful but somewhat simplified measure of health. It may not account for individual variations in muscle mass, bone density, and other factors. Your healthcare provider will consider these factors and your medical history. They will do this before prescribing weight loss medication.

Are there risks to taking weight loss medication?

FDA-approved drugs for weight loss are prescribed because of their safety and efficacy. They work, and the risks of side effects from their use are outweighed by their benefits.

These drugs do cause side effects in some patients, though. Different drugs cause different reactions.

Some of the most common side effects of weight loss medication include:

• Nausea
  
• Upset stomach
  
• Abdominal pain
  
• Constipation or diarrhea
  
• Dry mouth
  
• Increased heart rate
  
• Headaches
  
• Dizziness
  
  

You should always discuss a drug’s side effects with your provider before taking it. Let them know if you have a history of drug reactions or if you have any drug allergies.

In addition, tell your provider about any medications or supplements you are taking before taking a prescription drug. You should also tell them about your health history. Some conditions may affect the safety of weight loss medication.

Common medical conditions to discuss with your provider include:

• High cholesterol
  
• High blood pressure
  
• Heart disease
  
• Diabetes (type 1 or 2)
  
• Glaucoma
  
• Liver disease
  
• Kidney disease
  
• Thyroid disorders
  
• Thyroid tumors
  
• Pancreatitis
  
• Eating disorders
  
• Mental health conditions
  
  

Taking a weight loss drug while dealing with one of these conditions may lead to serious side effects.

Weight loss medication may not be prescribed to pregnant women, women who are trying to conceive, or women who are breastfeeding.

List of prescription weight loss medications

The U.S. Food and Drug Administration (FDA) has approved several prescription drugs to help with weight management. While healthcare providers may prescribe other medicines to help patients with weight loss, these drugs are currently the only available FDA-approved options. FDA-approved options include:

• Naltrexone-bupropion (Contrave)
  
• Orlistat (Alli and Xenical)
  
• Phentermine-topiramate (Qsymia)
  
• Liraglutide (Saxenda)
  
• Semaglutide (Wegovy)
  
• Tirzepatide (Zepbound)
  
  

These drugs work differently in the body to stimulate weight loss. In addition, they cause various side effects. Before starting treatment with any prescription weight loss medication, talk through your options with your healthcare provider to determine the best course of treatment for you.

In addition to these drugs, there are many medications that are prescribed for their off-label use in treating obesity and overweight.

Off-label use

"Off-label" refers to when a doctor uses a medication to treat a condition or symptom that it wasn't originally made for or officially approved for. This can occur for different reasons, like when a doctor thinks the medicine could help a patient even if it hasn't been officially tested and approved for that specific use.

Using medications off-label is allowed by law and can be important in medical care because it lets doctors customize treatments for each patient. Patients should be told when a medicine is being used off-label and have a chance to talk about it with their healthcare provider.

Some examples of drugs that are used off-label for their weight loss effects include:

• Bupropion (Wellbutrin)
  
• Exenatide (Byetta)
  
• Liraglutide (Victoza)
  
• Lorcaserin (Belviq)
  
• Metformin (Fortamet, Glucophage, Glumetza)
  
• Metreleptin (Myalept)
  
• Phentermine (Adipex-P, Lomaira)
  
• Pramlinitide (Symlin)
  
• Semaglutide (Ozempic, Rybelsus)
  
• SGLT2 Inhibitors (canagliflozin, dapagliflozin, empagliflozin)
  
• Topiramate (Topamax)
  
• Zonisamide (Zonegran)
  
  

These drugs are not explicitly used for weight loss. Talk to your healthcare provider before taking any of these medications for weight management.

Prescription weight loss drug facts

There are several different kinds of FDA-approved weight loss drugs. These medications are used differently, and work variously in the body to help with weight management. Here is more information about these treatment options, including how they are used, how they work, and possible side effects.

Drug name: Naltrexone and bupropion

Brand Names: Contrave

Basic Facts: Contrave combines naltrexone and bupropion. Naltrexone is an opioid antagonist. Bupropion is an antidepressant. Contrave works by suppressing appetite and helping patients control their cravings for unhealthy food.

Approved for: Adults and children over 12

Common side effects:

• Nausea
  
• Vomiting
  
• Headache
  
• Dizziness
  
• Fatigue
  
• Diarrhea
  
• Constipation
  
• Dry mouth
  
• Excessive sweating
  
• Changes in taste
  
  

Drug name: Orlistat

Brand names: Alli (Over-the-counter) and Xenical (prescription)

Basic facts: Orlistat is a lipase inhibitor. It helps patients reduce their body weight by keeping the intestines from absorbing fats in food. Unabsorbed fats are removed from the body via bowel movements.

Approved for: Adults and children over 12

Common side effects:

• Gas/ flatulence
  
• Stomach pain
  
• Abdominal pain
  
• Diarrhea
  
• Increased number of bowel movements
  
• Urgent need for a bowel movement
  
• Oily stools
  
• Oily spotting on underwear and clothes
  
• Loss of appetite
  
• Headache
  
• Nervousness/ anxiety
  
  

Orlistat can affect how your body absorbs essential vitamins like A, D, E, and K, which are necessary for your health. Your doctor might recommend taking a multivitamin and beta-carotene supplement when you use this medication.

Drug name: Phentermine and topiramate

Brand name: Qsymia

Approved for: Adults and children over 12

Basic facts: Qsymia is a combination drug. It contains a weight loss drug (phentermine) and an anticonvulsant (topiramate). Phentermine is a short-term use weight loss drug. It is also available in prescription medications like Adipex-P and Lomaira. Topiramate is usually used to treat seizures.

The combination of phentermine and topiramate helps suppress appetite. It may also make you feel fuller after eating a smaller portion. These two effects help reduce the calories you eat in a day.

Common side effects:

• Dry mouth
  
• Dizziness
  
• Tingling in the hands or feet
  
• Constipation
  
• Changes in taste
  
• Increased heart rate
  
• Fatigue
  
• Nausea and vomiting
  
  

Qsymia may cause changes to your mental health. Let your provider know if you begin to feel depressed or have suicidal thoughts while taking Qsymia.

Drug name: Liraglutide

Brand names: Saxenda, Victoza

Approved for: Adults and children over 12

Basic facts: Liraglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist. GLP-1 receptor agonists mimic the hormone GLP-1, which our intestines naturally release after meals. GLP-1 prompts the pancreas to release insulin, lowering blood sugar by allowing glucose into cells. It also blocks the release of glucagon, a hormone that raises blood sugar. It also slows stomach emptying to control nutrient absorption and promote a feeling of fullness. This aids in weight management and stabilizes blood sugar levels after eating.

Saxenda is a more potent form of liraglutide and is FDA-approved to treat obesity and overweight. Victoza is a weaker form of liraglutide. It is approved for long-term use to treat type 2 diabetes.

Common side effects:

• Headache
  
• Injection site reactions
  
• Constipation
  
• Stomach pain
  
• Heartburn
  
• Fatigue
  
• Runny nose, sneezing or coughing
  
  

Drug name: Semaglutide

Brand names: Wegovy, Ozempic, and Rybelsus

Approved for: Adults and children over 12

Basic facts: Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist. GLP-1 receptor agonists mimic the hormone GLP-1, which our intestines naturally release after meals. GLP-1 prompts the pancreas to release insulin, lowering blood sugar by allowing glucose into cells. It also blocks the release of glucagon, a hormone that raises blood sugar. It also slows stomach emptying to control nutrient absorption and promote a feeling of fullness. This aids in weight management and stabilizes blood sugar levels after eating.

Semaglutide, prescribed as Wegovy, is FDA-approved to treat obesity. It is also prescribed in a lower dose, as Ozempic or Rybelsus, to help patients with type 2 diabetes manage their blood sugar. Ozempic and Rybelsus may be prescribed off-label to help with weight loss. Only Wegovy is specifically approved for weight loss.

Common side effects:

• Gas
  
• Abdominal pain
  
• Nausea
  
• Diarrhea
  
• Constipation
  
• Heartburn
  
  

Drug name: Tirzepatide

Brand name: Zepbound, Mounjaro

Approved for: Adults and children over 12

Basic facts: Tirzepatide is a newcomer among weight loss medicines. Approved in 2023, it is a novel class of drugs known as dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonists.

Zepbound does all the things a GLP-1 receptor agonist does. It also encourages the release of the GIP hormone.

GIP is released by the gut when we eat. It tells the pancreas to release insulin, helping our cells use sugar from food and preventing the liver from making too much sugar. Researchers are still studying GIP's direct impact on weight loss. It helps manage weight by controlling blood sugar levels and reducing cravings for sugary foods.

Tirzepatide is also sold under the brand name Mounjaro. Mounjaro is usually used to treat type 2 diabetes. Some providers may prescribe it off-label for weight loss.

Common side effects:

• Upset stomach
  
• Gas
  
• Constipation
  
• Diarrhea
  
• Loss of appetite
  
• Injection site reactions
  
• Fatigue
  
  

How Sesame can help

If you struggle to lose weight, prescription weight loss medications can help. These should not replace a healthy diet and regular exercise. However, when used with those lifestyle changes, weight loss drugs are a powerful ally in helping you achieve and maintain a healthy weight.

If you’re trying to lose weight and think prescription weight loss medication may be right for you, talk to a provider on Sesame. Sesame now offers an online weight loss program to help you start your weight loss journey.

Sesame’s online weight loss program is a subscription that renews every 3 months. The program includes a video consultation with a weight loss doctor or specialist, a GLP-1 prescription (if appropriate), insurance coordination for medication coverage, and 90 days of unlimited messaging with your provider.

Sources:

• (2023). Prescription Medications to Treat Overweight & Obesity. NIDDK.
  
• Latif W, Lambrinos KJ, Rodriguez R. (2023). Compare and Contrast the Glucagon-Like Peptide-1 Receptor Agonists (GLP1RAs). National Library of Medicine.
  
• Munoz-Mantilla, D., MD. (2023). Top Weight Loss Medications. Obesity Medicine Association.
  
• Tak, Y. J., & Lee, S. Y. (2021). Long-Term Efficacy and Safety of Anti-Obesity Treatment: Where Do We Stand?. National Library of Medicine.
  
• Tchang BG, Aras M, Kumar RB, et al. (2021). Pharmacologic Treatment of Overweight and Obesity in Adults. National Library of Medicine.