Stopping Mounjaro, Zepbound Injections Led to “Substantial” Regain of Lost Weight, Study Warns

The findings indicate that continued use of Mounjaro or Zepbound is needed to maintain weight loss, amid increasing reports that some users may be left with permanent gastrointestinal side effects.

Patients who stop taking Mounjaro or Zepbound injections, due to stomach paralysis or other side effects that lead to discontinuation of the diabetes and weight loss drugs, are likely to regain any of the weight they loss during the treatments, according to the findings of a new study.

A multinational group of researchers, including scientists from Eli Lilly, the drugs’ manufacturer, found that more than 80% of recipients of injections of tirzepatide, the active ingredient in Mounjaro and Zepbound, reported adverse events during treatment, with most reporting gastrointestinal problems.

In findings published earlier this month in the Journal of the American Medical Association (JAMA), researchers warn that when patients began receiving a placebo, instead of the actual injections later in their treatment, their lost weight started to return.

Mounjaro Weight Loss Benefits Have Resulted in Widespread Use

Eli Lilly introduced Mounjaro (tirzepatide) last year, as part of a new generation of treatments for diabetes, which is a chronic and progressive condition that causes insulin resistance and insufficiency. It is part of the same class of new drugs as Ozempic (semaglutide), and both medications have been widely prescribed “off-label” for weight loss, given the positive effect they have helping to reduce hunger, decease food intake and promote feelings of fullness.

Last month, the U.S. Food and Drug Administration (FDA) announced the approval of Zepbound, a tirzepatide injection specifically authorized for chronic weight management in adults with obesity.

The FDA approval indicated that Zepbound side effects can include nausea, diarrhea, vomiting, constipation, abdominal pain and other symptoms. However, there have been a growing number of reports in recent months of some users experience severe and debilitating stomach paralysis from Ozempic, Wegovy and Mounjaro, sometimes resulting in intestinal obstructions, hospitalization and surgery.

As a result of the failure to disclose the potential long-term impacts of this condition, also known as gastroparesis, some former users are now pursuing Mounjaro lawsuits, Ozempic lawsuits and Wegovy lawsuits against the drug manufacturers, indicating that they could have avoided permanent injuries if the side effects had been properly disclosed.

Stopping Mounjaro, Zepbound Injections Led to Regaining Weight

In this latest study, researchers conducted a randomized withdrawal clinical trial at 70 sites in four countries involving 783 participants. They were given regular injections of tirzepatide for 36 weeks, which was followed by a 52-week, double-blind placebo controlled period, with 335 patients continuing to receive the normal injections, and 335 patients being given a placebo instead.

According to the findings, all patients experienced about a 21% mean weight reduction on Mounjaro and Zepbound. However, those patients who were switched to a placebo regained 14% of the weight they had previously lost, while those continuing treatment lost another 5.5% of their weight.

The researchers also found that a total of 81% of participants reported at least one treatment-related adverse event after receiving the injections, with 35.5% linked to nausea, 21.1% reporting diarrhea, 20.7% suffering from constipation and 16.3% reporting vomiting. Those problems remained for 60.3% of patients receiving the injections throughout the study period. The data indicates about 7% of participants discontinued treatment due to these health problems.

About 2% of the patients suffered serious adverse events during the first phase of the trial, and 3% during the double-blind period. Three deaths occurred during the study, but none were linked to side effects of Mounjaro or Zepbound.

“In participants with obesity or overweight, withdrawing tirzepatide led to substantial regain of lost weight, whereas continued treatment maintained and augmented initial weight reduction,” the researchers concluded. “At least 5 trials (including the present study) across various classes of medications, including potent antiobesity medications such as semaglutide, have demonstrated that weight is substantially regained after cessation of pharmacotherapy.”

Mounjaro Stomach Paralysis Risks

The findings of this latest study suggest that patients who begin taking Mounjaro or Zepbound must stay on the drug if they wish to keep the weight they’ve lost from returning. However, that could present some problems for patients suffering the effects of stomach paralysis linked to the entire class of medications, known as glucagon-like peptide-1 (GLP-1) receptor agonists, which also includes Ozempic and Wegovy.

In July, the American Society of Anesthesiologists (ASA) issued a warning about using Ozempic and Wegovy before surgery, indicating that the lack of gastric emptying linked to the drugs could put patients at risk of vomiting and aspiration while under the effects of anesthesia. Similar side effects are linked to Mounjaro, which could also pose a problem during surgical anesthesia.

In 2017, researchers with the Mayo Clinic conducted a study involving a similar diabetes medication known as Victoza, which found that the drug caused significantly slower digestion in users, taking about 70 minutes for half the food they ate to leave their stomachs, compared to four minutes for people who did not take the drug. However, the study found that people’s bodies tended to adjust over time.

In September, the U.S. Food and Drug Administration (FDA) issued new label warnings for Ozempic, indicating that it can increase the risk of intestinal blockages. The warning links Ozempic to a condition known as ileus, which can cause abdominal cramps, bloating, nausea, vomiting, constipation, difficulty passing gas and difficulty eating.