Obesity Playbook: Antiobesity Medications

As of March 2023, the FDA has approved the use of five medications for long-term treatment of overweight and obesity.

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March 24, 2023

For employers seeking to align their weight management strategy with the latest evidence, this resource offers recommendations on creating a comprehensive benefits package to treat obesity, including behavior-based interventions and pharmacological and surgical treatment.

What Are Antiobesity Medications?

As of March 2023, the FDA has approved the use of five medications for long-term treatment of overweight and obesity:

  • Orlistat* (Xenical®);
  • Liraglutide (Saxenda®);
  • Phentermine-topiramate (Qsymia®);
  • Naltrexone HCl/bupropion HCl (Contrave®); and
  • Semaglutide (Wegovy®).

In addition to the medications listed above for long-term use, the FDA has approved weight loss medications for short-term use only (less than 12 weeks). These include the generic drugs phentermine and diethylpropion.1

There are also numerous FDA-approved medications that are prescribed off-label to treat overweight or obesity because they have demonstrated weight loss as a side effect. These include but aren’t limited to medications to treat diabetes (including GLP-1s like Ozempic®), depression and seizures.

*A lower dose of the medication (60 mg) is available over the counter under the brand name Alli®

Are GLP-1s Antiobesity Medications?

GLP-1 agonists (GLP-1s) are a class of drugs that have been used to treat type 2 diabetes for years. Two have been approved to treat people with overweight or obesity without diabetes - Saxenda® and Wegovy® - and several more are in the drug development pipeline. Tirzepatide®, a novel medication that acts as a dual GLP-1 and GIP receptor agonist, received ‘Fast Track’ designation by the FDA in October 2022, a “process designed to facilitate the development, and expedite the review of drugs to treat serious conditions and fill an unmet medical need."2,3 Tirzepatide has gained attention prior to FDA approval due to data showing greater than 20% weight loss in more than 50% of trial participants who received the highest weekly dosing. These medications are categorically different from prior antiobesity medications, with data indicating positive effects beyond weight loss to also include cardiometabolic outcomes, along with an encouraging safety profile.

GLP-1s have been heralded for their potential to help people with obesity achieve clinically significant weight loss, but they present unique considerations for employers due to their cost and the chronic nature of their use. Saxenda® and Wegovy® are given at higher doses for the treatment of overweight and obesity than for diabetes (1.0 mg or less once weekly for diabetes vs. 2.4 mg once weekly for overweight or obesity). This higher dosing, as well as the rebranding of GLP-1s from diabetes medications to antiobesity medications, is driving up their price. To illustrate, when Wegovy® came to market in 2021, a 28-day supply was $1,627 based on pricing information from GoodRx.4 According to the 2021 CVS Health Drug Trend Report, antiobesity medications were one of three classes of drugs driving nonspecialty spend primarily due to increases in the cost and utilization of GLP-1s.5

For Whom are Antiobesity Medications Indicated?

All five antiobesity medications approved for long-term use are indicated for adults with a BMI ≥30 or BMI ≥27 with a weight-related comorbidity. Four medications (Orlistat®, Saxenda® Qsymia® and Wegovy®) have also been approved for use in adolescents with overweight or obesity.6-8 All antiobesity medications are intended to be used as an adjunct to lifestyle interventions.

Why Should Employers Consider Providing Coverage for Antiobesity Medications?

Many people with overweight and obesity cannot achieve clinically significant weight loss through lifestyle interventions alone. That’s because those with overweight and obesity are grappling with their own biology as they try to lose weight and keep it off; as people lose weight, appetite increases and metabolism slows, which is the body’s way of re-establishing its so-called ‘setpoint’ (the amount of fat our brain believes is necessary to sustain proper functioning).9,10

For those who qualify, antiobesity medications can be a useful tool alongside intensive behavioral interventions to help lose weight and keep it off; clinical trials, along with studies of employees in the real world, show that people with overweight or obesity who take an antiobesity medication and engage in behavior change interventions achieve greater weight loss than those who engage in behavior change interventions alone.

What Is the Efficacy of Antiobesity Medications in Adults?

While efficacy varies, clinical trials show that people who take antiobesity medications are more likely to lose at least 5% of their body weight than those who take placebo. Among these medications, the greatest weight loss is associated with semaglutide (Wegovy®); the largest clinical trial of this drug showed that when semaglutide was used in conjunction with lifestyle changes, it led to an average 14.9% reduction in body weight after 68 weeks.11 High-dose phentermine-topiramate (Qsymia®) was associated with the second greatest weight loss among FDA-approved antiobesity medications; at 108 weeks – the longest study of this drug – those who took a higher dose of phentermine-topiramate lost 10.5% of their baseline weight.12 Specific information on the effectiveness of the five FDA-approved antiobesity medications is included in the Appendix.

Beyond clinical trial data, the efficacy of antiobesity medications has been evaluated in an employer population. Results from the study showed greater weight loss among those who received an antiobesity medication and participated in an employer-based weight management program than those who participated in the weight management program alone. Participants who received the antiobesity medication were more likely to lose 5% of their body weight and were more adherent to the weight management program than those who didn’t.13

As with medications used to treat high blood pressure, cholesterol or diabetes, the benefits of antiobesity medications may only be realized while patients remain on the drug regimen. According to a study that examined the health and weight effects on patients who had taken semaglutide for 68 weeks and subsequently stopped taking it, after 1 year “participants regained two‐thirds of their prior weight loss, with similar changes in cardiometabolic variables.”14 Discontinuing use may lead to weight regain because of the mechanism by which GLP-1s work: They delay stomach emptying and decrease appetite, but once people stop taking these medications, feelings of hunger return.15 The long-term nature of these medications is raising concerns among employers because their costs far exceed that of other drugs used to treat chronic conditions.

Efficacy of Antiobesity Medications in Adolescents

While the efficacy of antiobesity medications in adolescents varies, studies of Orlistat®, Saxenda® and Qsymia® and Wegovy® show that BMI decreased among those who took antiobesity medications. Among adolescents who did not take antiobesity medications, BMI either increased or did not change.8,16,17,18

What Is the Safety Profile of Antiobesity Medications?

Side Effects

As with any drug, there are risks associated with antiobesity medications. Clinical trial data show that side effects vary by medication but include dizziness, headaches, dry mouth, nausea, diarrhea and constipation. Patients who take GLP-1s and lose weight may also lose muscle mass; this has been highlighted as an important consideration because people taking these medications may need to alter their diet and physical activity to account for this loss.19 All five antiobesity medications are contraindicated in pregnancy; other contraindications and precautions vary by drug type and age (adolescents vs. adults).

Cardiovascular Safety

Beginning in 1997, several medications for weight loss were withdrawn from the market in the U.S. due to serious side effects, including adverse cardiovascular outcomes. Because of this, the FDA now requires approved medications to undergo post-marketing trials to assess cardiovascular effects; these studies are ongoing.20

Thus far, clinical trial data assessing the efficacy of antiobesity medications have demonstrated positive effects on cardiometabolic risk factors (e.g., cholesterol), and few adverse cardiovascular events have been reported. In fact, because of their broader cardiometabolic benefits, GLP-1s are being studied in certain populations for the primary and secondary prevention of cardiovascular disease.21

Cancer Risk

In 2020, lorcaserin (Belviq®) was withdrawn after a safety clinical trial showed an increased occurrence of cancer in those taking the drug.22 As with other FDA-approved medications, future studies are needed to assess long-term effects of these medications.

What Is the Utilization of Antiobesity Medications?

Utilization of antiobesity medications has historically been low but is increasing. According to a study published in 2021, less than 1% of adults eligible for antiobesity medications took them between 2015 and 2018.23 During the study period, utilization increased between 2015 and 2016 and 2017 and 2018, particularly for newer medications.23 Patients between the ages of 18 and 64 who had commercial insurance showed the highest rates of use.23 Such low utilization has been attributed to a number of factors, including but not limited to: inconsistent coverage, patient and provider beliefs about the usefulness of antiobesity medications, safety concerns, limited provider experience prescribing antiobesity medications and cost (according to GoodRx, in 2021, a 28-day supply of Wegovy® was $1,627, $1,626 for Saxenda®, $873 for Xenical®, $369 for Contrave® and $236 for Qysmia®.4,5,24-28

In the last 2 years, utilization of antiobesity medications has increased markedly, particularly for GLP-1s: According to CVS Health, there was 15% growth in utilization from the third quarter in 2020 to the third quarter of 2021 for antiobesity drugs, with Saxenda® and Wegovy® driving this trend.5 Due to increased utilization, Wegovy® has been in short supply.29 For more information on the factors driving increased utilization of GLP-1s and associated considerations, see Managing Blockbuster GLP-1 Medications: What Employers Need to Know and What They Can Do.

In acknowledgment of the role that antiobesity medications can play in the treatment of overweight and obesity, the U.S. Office of Personnel Management (OPM), the chief human resource agency for the federal government, included requirements about antiobesity medications in its Federal Employees Health Benefits (FEHB) Program carrier letter and technical guidance for the 2023 plan year.30 In its letter, the agency stated: “OPM is clarifying that FEHB Carriers are not allowed to exclude anti-obesity medications from coverage based on a benefit exclusion or a carve out. FEHB Carriers must have adequate coverage of FDA approved anti-obesity medications on the formulary to meet patient needs and must include their exception process within their proposal. In cases where utilization management edits are applied, the process and evidence-based criteria for coverage must be transparent, readily accessible, and follow OPM required turnaround timelines.”31 As noted in a commentary in the journal Health Affairs, this requirement will greatly expand access to antiobesity medications since OPM offers more than 200 health plans across the U.S. and covers more than 8 million lives.32

What Should Employers Consider When Assessing and Implementing Coverage for Antiobesity Medications?

  • Do you already include pharmacotherapy in your company’s weight management strategy? Check your summary plan description(s) to confirm whether your plan(s) include antiobesity medications since the inclusion of these medications on preferred formularies is not standard across PBMs. If you currently cover antiobesity medications or wish to in the future, consider including multiple agents in your formulary; while employees with overweight or obesity may respond favorably to at least one drug, it may not be the same medication. Covering multiple agents also provides the opportunity to implement step therapy.
  • What is the current cost and utilization of off-label prescribing? Work with your partners to determine utilization and costs associated with medications prescribed off label for weight loss, as numerous drugs have been approved by the FDA to treat other conditions (such as type 2 diabetes) and are being used to help patients lose weight. While some of this off-label prescribing may be thoughtful and appropriate, there are other instances where it is not. Clarifying the cost and utilization of off-label use may help organizations that do not currently cover antiobesity medications understand the implications of doing so. It may also help with the decision to implement potential strategies to promote appropriate use.
  • What type of utilization management tools should be implemented to ensure appropriate use? Ask existing or prospective vendor partners about their prior authorization process to promote appropriate access and utilization of antiobesity medications.
  • How are intensive behavioral interventions integrated with antiobesity medications? Promote the use of intensive behavioral interventions alongside pharmacotherapy, as the combination of these programs with antiobesity medications leads to clinically significant weight loss. Some employers pair intensive behavioral interventions and antiobesity medications as part of their on-site services, and some weight management programs now combine the two as part of their care model. Personalized communication may also be helpful; talk with your partners to identify ways of promoting participation in behavioral interventions when employees are prescribed antiobesity medications. Communications may also include the promotion of other benefits, programs or discounts to assist employees on their weight loss and maintenance journey.

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More in Well-being and Workforce Strategy


  1. What Are Antiobesity Medications?
  2. Are GLP-1s Antiobesity Medications?
  3. For Whom are Antiobesity Medications Indicated?
  4. What Is the Efficacy of Antiobesity Medications in Adults?
  5. What Is the Safety Profile of Antiobesity Medications?
  6. What Is the Utilization of Antiobesity Medications?
  7. What Should Employers Consider When Assessing and Implementing Coverage for Antiobesity Medications?