New Drug Could Cut GLP-1 Side Effects for Patients

A new clinical trial suggests tradipitant may reduce vomiting for adults taking semaglutide for weight management.

Updated on Oct. 27, 2026 in Weight Loss

A glass laboratory dropper and beaker filled with clear liquid rest on a stainless steel surface, highlighting medical research. — Vanda Pharmaceuticals reports that tradipitant, in a phase 3 trial, significantly reduced vomiting and nausea in patients taking semaglutide for weight management. AI Illustration. Upload story photo >

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Vanda Pharmaceuticals has announced results from a phase 3 trial showing that its drug tradipitant may reduce vomiting for people taking semaglutide. This development is significant as nausea and vomiting are primary reasons many patients discontinue GLP-1 weight-loss therapy.

Why it matters

Gastrointestinal side effects are a major hurdle for long-term adherence to GLP-1 medications, which are widely prescribed for weight management. Reducing these symptoms could help more patients sustain their treatment regimens as prescribed.

In a phase 3 randomized, placebo-controlled trial, 142 participants receiving tradipitant saw a 27% relative reduction in any vomiting compared to 164 participants in the placebo group after a 1 mg dose of semaglutide. These results are currently preliminary as the company prepares for further regulatory engagement.

The players

Vanda Pharmaceuticals

A biopharmaceutical company focused on developing therapies for central nervous system and gastrointestinal disorders.

FDA

The federal agency responsible for evaluating the safety and efficacy of new drugs and medical treatments in the United States.

The details

Tradipitant functions by blocking substance P signaling within the central emetic pathways that trigger nausea and vomiting. The trial specifically assessed its efficacy against gastrointestinal side effects induced by a single 1 mg dose of semaglutide. Beyond the primary reduction in any vomiting, the data indicated a 35% relative reduction in instances of vomiting plus significant nausea, alongside substantial decreases in frequent multiday and extreme vomiting episodes.

August 2025: Semaglutide 2.4 mg received FDA approval for MASH.
December 2025: Tradipitant was approved for motion-induced vomiting.
October 27, 2026: Study 3601 results were officially announced.
2027: Vanda Pharmaceuticals plans to meet with the FDA regarding results.

Health Landscape

Current data suggests that 53.6% of U.S. adults discontinue GLP-1 therapy within one year, often due to gastrointestinal side effects. This research attempts to improve long-term adherence within a market that has expanded significantly.

Patients who struggle with persistent nausea or vomiting on GLP-1 medications should monitor their symptoms and discuss their impact on adherence with their healthcare provider. While this study shows promise, it is important to wait for further regulatory guidance before expecting this to be a treatment option.

The takeaway

Nausea and vomiting are major barriers to remaining on GLP-1 therapy, and new research is exploring ways to manage these side effects. Keep track of any specific triggers for your symptoms and discuss the severity of your GI side effects with your doctor at your next checkup.

What happens next

Vanda Pharmaceuticals intends to initiate a formal meeting with the FDA in 2027 to discuss these clinical trial results and the path toward a supplemental New Drug Application.