Everything You Need To Know About The New Weight Loss Drugs

Jenny Niwa, National Center for Health Research

You have probably heard about 2 very popular new weight loss drugs, Ozempic.  Although Ozempic is specifically for treating diabetes, both are being used by people who want to lose weight. Before you decide whether to take these drugs, here are some things you should know.

What are these drugs and how do they work?

 The FDA approved Ozempic in 2017 for the treatment of type 2 diabetes and Wegovy in 2021 for weight loss for adults with obesity or who are overweight and have at least one weight-related health condition.  Although these drugs have been on the market for several years, their popularity really exploded in 2023. While Ozempic is not approved specifically for weight loss, doctors may prescribe it off-label. Both Ozempic and Wegovy curb hunger and reduce the intake of food. The medications are currently administered by injection once a week, but they may soon be available in pill form.

Both Wegovy and Ozempic use the medication semaglutide, which mimics the GLP-1 hormone which is naturally made by the body. GLP-1 has two major roles. One is to slow the passage of food through the stomach, which helps people feel fuller longer. The other is glucose control, by promoting insulin release and helping reduce blood sugar. Saxenda is a somewhat older FDA-approved  GLP-1 weight loss drug, but because it requires daily injections and has less dramatic impact on weight loss, it is not as popular as Wegovy or Ozempic.^[1]

What do research studies say? 

In 2023, Wegovy’s maker, Novo Nordisk claimed that the drug reduced the risk of serious heart problems. The company described a randomized trial of 17,500 patients with obesity and heart disease, although patients with diabetes were excluded.^[2] Half of the participants received regular injections of Wegovy and the other half received a placebo. Rather than publish the results in a peer-reviewed journal, Novo Nordisk publicized their research in a press release that claimed that Wegovy reduced heart attacks, strokes, and deaths by 20% compared to placebo, and this was widely reported in the media. However, this statistic is misleading because it is a relative risk. Since the risk of heart attack, stroke, or death was about 8% for those not taking Wegovy, a 20% reduction reduced that to 6.4% — so it is really a reduction of only 1.6%. As of August 29, 2023, the study has not yet been published in a peer-reviewed journal and the company has not revealed how much weight patients lost in the trial or whether the weight loss was maintained during the 5 years of the trial period.^[3] Instead, Novo Nordisk has stated it would present more detailed results at a scientific conference later this year; however, peer reviews for scientific conferences are usually less rigorous than those of major medical journals.

In August 2023, a study published in the New England Journal of Medicine reported that Wegovy improved the quality of life in people with the most common form of heart failure. This study included patients with heart failure. For those who took Wegovy weekly, there was a 17-point improvement in symptoms on a 100-point scale, primarily due to less shortness of breath, fatigue, trouble exerting themselves, and swelling. Patients who took the placebo saw a 9-point improvement.

Although the 2023 announcements received a great deal of media attention, a previous study of Ozempic published in 2016 in the New England Journal of Medicine, found that the medication reduced the risk of heart problems for diabetes patients at high risk for cardiovascular complications.^[4] This study included more than 3,000 patients with type 2 diabetes, who were randomly assigned to receive once-weekly Ozempic or a placebo for 104 weeks. Results showed that 108 of 1648 patients (6.6%) taking Ozempic either died, had a nonfatal heart attack, or nonfatal stroke, compared to 146 of 1649 patients (8.9%) who took the placebo.  This was statistically significant (which means it did not occur by chance), but is a difference of only 2.3%.

What are the side effects?

The most common side effects of GLP-1 medications like Wegovy and Ozempic include stomach issues such as nausea and diarrhea. In extreme cases, some patients experienced persistent vomiting or cyclic vomiting syndrome and severe gastroparesis. Gastroparesis is stomach paralysis and occurs when there is a delay or stopping in food movement from the stomach to the small intestine.

Warnings about other possible serious side effects that are listed on the company’s Wegovy website include inflammation of the pancreas, gallbladder problems, increased risk of low blood sugar, kidney problems, serious allergic reactions, change in vision for people with type 2 diabetes, increased heart rate, and depression and thoughts of suicide.^[5]

An even more serious side effect is the risk of thyroid cancer. According to a study conducted by the European Medicines Agency (EMA, which is the European version of the FDA), researchers found that using GLP-1 medications for 1-3 years may increase the risk for all types of thyroid cancers.^[6]

Another side effect that you need to consider is potential complications from anesthesia for people taking these drugs. The American Society of Anesthesiologists advises that people taking these drugs should make sure to stop taking the medication a week before surgery. People who know they are going to have surgery are advised not to eat for 24 hours before surgery, but since these drugs affect how long food stays in the stomach, a 24-hour fast is not enough to prevent regurgitating food during the operation. This is dangerous because vomiting under anesthesia can cause pneumonia and other fatal problems due to the food and stomach acid getting into the lungs.^[7]  This risk may be impossible to prevent if someone taking the drug requires emergency surgery.

What Happens if You Lose Weight and Want to Stop Taking the Drug?

Most weight loss strategies work for a limited time; when people stop dieting or exercising they gain the weight back.  The long-term benefits of these drugs are also likely to be limited because when they stop taking the drugs, their stomach no longer feels full. A study conducted with almost 2,000 adults without diabetes found that one year after no longer taking Wegovy, participants regained two-thirds of their prior weight loss.^[8] 

There is still much that is unknown about these drugs. It is unclear how these drugs affect patients after years of use, whether the drugs are effective at maintaining a certain weight after long-term use, and whether most patients will benefit from taking the drugs for a limited period of time or if they need to stay on for the rest of their lives.

Other Questions to Consider

In 2022, Novo Nordisk spent a total of $11 million to promote their Ozempic and other weight-loss drugs, including $9 million on meals and $2 million on travel for thousands of doctors to promote their weight-loss drugs.^[9] That included more than 457,000 meals; nearly 12,000 prescribers had food paid for by the company more than a dozen times in that one year. Buying meals for doctors is not illegal, but this extreme level of “generosity” raises concerns. If these drugs are so effective, why did the company think it necessary to provide all these free meals?  Are doctors prescribing these drugs because they are confident of the benefits of these drugs, or have they been unduly influenced to prescribe them?  

Is taking these weight loss drugs right for you?

Ozempic is FDA approved for patients with type 2 diabetes and is not approved for weight loss. Wegovy is FDA-approved only for patients with obesity, or who are overweight and have at least one weight-related health condition. Due to the risk of thyroid cancer, if you or any family member has ever had a type of thyroid cancer, taking Wegovy may be dangerous. Similarly, if you have sensitivity to gastrointestinal problems, this drug may not be right for you.

Another thing to consider is the cost, which is much higher in the U.S. compared to other countries.^[10] If insurance does not cover the cost, one monthly dose of Ozempic costs about $900, and the cost for Wegovy is about $1,350.^[11],[12] Since they are relatively new, there are no generic versions of Ozempic or Wegovy. You may be able to lower the costs of these drugs through savings programs or through coverage on your health insurance plan. Many private insurance providers cover Wegovy and Ozempic when it’s used to treat Type 2 diabetes. When used for weight-loss purposes, it is much less likely to be covered. Medicare does not cover these drugs, although the program is under pressure to do so.

The media attention to these 2 drugs makes it seem that they are the only FDA-approved weight loss drugs. They are not. However, all weight loss drugs have unpleasant and potentially serious side effects, and these 2 seem to be more effective.

If you are eligible and interested in taking these drugs, you should first and foremost make sure to talk to your physician and discuss what to expect, the possible side effects, and your medical history. If you are not eligible for these drugs or are not interested in using them, there are still many alternative weight loss methods available. These include exercising daily or regularly, developing healthier eating habits, and knowing when to eat.

[1] Hoffman, S. (2023) The Differences between Saxenda and Wegovy. Very Well Health. https://www.verywellhealth.com/the-differences-between-saxenda-and-wegovy-7564310

^[2] Chen, E., and Joseph, A. (2023). Novo’s obesity drug Wegovy lowers cardiovascular risk by 20%, landmark trial finds. STAT+. https://www.statnews.com/2023/08/08/novo-nordisk-wegovy-cardiovascular-risk/

^[3] Mueller, B. (2023). Weight Loss Drug Cuts Risk of Heart Problems, Maker Says. The New York Times. https://www.nytimes.com/2023/08/08/health/wegovy-obesity-drugs-heart-disease.html

^[4] Marso, S., Bain, S., Consoli, A., & Eliaschewitz, F. (2016). Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes. The New England Journal of Medicine. https://www.nejm.org/doi/full/10.1056/nejmoa1607141

^[5] Novo Nordisk. (n.d.). Tips for managing common side effects. https://www.wegovy.com/dashboard/my-library/week-02-tips-for-managing-common-side-effects.html#:~:text=thoughts%20of%20suicide.-,The%20most%20common%20side%20effects%20of%20Wegovy%C2%AE%20may%20include,runny%20nose%20or%20sore%20throat.

^[6] Bezin, J., Gouverneur, A., Penichon, M., Mathieu, C., Garrel, R., Hillaire-Buys, D., Pariente, A., & Faillie, J.L. (2022). GLP-1 Receptor Agonists and the Risk of Thyroid Cancer. Diabetes Care. https://diabetesjournals.org/care/article-abstract/46/2/384/147888/GLP-1-Receptor-Agonists-and-the-Risk-of-Thyroid?redirectedFrom=fulltext

^[7] Goodman, B. (2023). They took blockbuster drugs for weight loss and diabetes. Now their stomachs are paralyzed. CNN. https://www.cnn.com/2023/07/25/health/weight-loss-diabetes-drugs-gastroparesis/index.html

^[8] Wilding, J. P., Batterham, R. L., Davies, M., Van Gaal, L. F., Kandler, K., Konakli, K., Lingvay, I., McGowan, B. M., Oral, T. K., Rosenstock, J., Wadden, T. A., Wharton, S., Yokote, K., &  Kushner, R. F. (2022). Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extension. Diabetes, Obesity and Metabolism, 24(8), 1553–1564. https://doi.org/10.1111/dom.14725

^[9] Florko, N. (2023). Novo Nordisk bought prescribers over 450,000 meals and snacks to promote drugs like Ozempic. STAT+. https://www.statnews.com/2023/07/05/ozempic-rybelsus-novo-nordisk-meals-for-doctors/#:~:text=Novo%20Nordisk%20bought%20prescribers%20over,to%20promote%20drugs%20like%20Ozempic&text=WASHINGTON%20%E2%80%93%20Novo%20Nordisk%20spent,weight%20loss%2Dinducing%20diabetes%20drugs

^[10] Amin, K., Telesford. I., Singh, R., & Cox, C. (2023). How do prices of drugs for weight loss in the US compare to peer nations’ prices? Health System Tracker. https://www.healthsystemtracker.org/brief/prices-of-drugs-for-weight-loss-in-the-us-and-peer-nations/?utm_campaign=morning_rounds&utm_medium=email&_hsmi=270760455&_hsenc=p2ANqtz-_P2SZN9DLjS_l7fSn8hrgS8xRf4YvJIonV0X-iRtKF3FtcWbgsMJd-K6tDV2u12XNFMEesDCulwlbdwkw74D1S-2WqXQ&utm_content=270760453&utm_source=hs_email#List%20prices%20of%20drugs%20used%20for%20weight%20loss%20in%20the%20U.S.%20and%20peer%20nations

^[11] Wilson, A. (2023). How much does Ozempic cost without insurance?. RO. https://ro.co/weight-loss/ozempic-cost-without-insurance/

^[12] Wilson, A. (2023). How much does Wegovy cost? RO. https://ro.co/weight-loss/wegovy-cost/

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