Tradipitant for GLP-1 Nausea: Nereus Phase 3 Results

Can a pill stop the nausea and vomiting that come with Ozempic, Wegovy or Zepbound? A drug called tradipitant (brand name Nereus) just showed it can lower vomiting after a semaglutide shot, but it is not approved for that use yet. On October 27, 2026, Vanda Pharmaceuticals said its Phase 3 Study 3601 met its main goal. Vomiting dropped from 58.5% of people on placebo to 43.0% on tradipitant. Nereus is FDA approved today only to prevent vomiting from motion sickness.

Here is what the drug is, what the trial really tested, and what you can do about GLP-1 nausea right now.

What is tradipitant (Nereus)?

Tradipitant is a pill that blocks the NK-1 receptor. Your brain uses a chemical called substance P to switch on vomiting, and it acts through this receptor in the brain's vomiting center. Block the receptor and the signal gets weaker.

Key facts from the FDA label and Vanda:

GLP-1 drugs cause nausea partly by acting on the same part of the brain, an area called the area postrema. That is why Vanda thinks an NK-1 blocker could work with any GLP-1 drug, not just semaglutide.

Tradipitant GLP-1 trial results: what Study 3601 found

Vanda gave adults a single 1 mg dose of semaglutide, the drug in Ozempic and Wegovy, with no slow build-up. In real life, people start at 0.25 mg and step up over weeks. Jumping straight to 1 mg was meant to cause a lot of vomiting, so the study could see whether tradipitant prevents it.

*Post hoc analyses, which Vanda calls supportive evidence. Source: Vanda press release, October 27, 2026.

A few plain-English points:

• The main drop was 27%. That is a relative cut. In raw numbers, about 15 fewer people out of every 100 vomited.
• The worst cases shrank the most. Very heavy vomiting fell by about 80%.
• Days 1 and 2 matter most. Almost all vomiting happened by Day 2. Vanda says the best time to prevent it is right before starting or raising a GLP-1 dose.
• No new safety problems. Vanda said the drug was generally well tolerated, but it did not release detailed side effect rates for this study.

This was not the first try. A smaller Phase 2 study from November 2025 (116 people, also given 1 mg Wegovy without titration) cut vomiting from 58.6% to 29.3%. Vanda also registered a second GLP-1 trial, the Thetis study, on ClinicalTrials.gov.

What these results do not tell you yet

Be careful with the headlines. Three limits stand out:

1. It is one shot, not months of treatment. The study did not test people taking a GLP-1 week after week with normal dose steps.
2. The results come from the company. They have not been published in a peer-reviewed journal yet.
3. There is no GLP-1 approval. The FDA has not reviewed tradipitant for this use, and there is no timeline.

Vanda says a pooled analysis showed the effect held steady at lower semaglutide levels, which supports use with normal dosing. That still needs FDA review.

Is tradipitant FDA approved, and can you get it?

Nereus is approved, but only for motion sickness. A prescriber could choose to use an approved drug for another reason (called off-label use), but that is a medical decision with real trade-offs. The label warns that Nereus can make you sleepy and affect driving. The risk goes up with alcohol, other sedating drugs, and strong CYP3A4 inhibitors (some antifungals and antibiotics). The label also says to watch breastfed babies for sleepiness. If GLP-1 nausea is a problem for you, bring it up with your prescriber instead of looking for a workaround.

We could not confirm a published list price for Nereus. Ask your pharmacy for a quote, and expect insurance to be unsure about any off-label use.

How tradipitant compares to other anti-nausea drugs

None of these is FDA approved for GLP-1 nausea today. Tradipitant is the first one with a Phase 3 study built around a GLP-1 drug.

What helps GLP-1 nausea right now

Most nausea on these drugs is worst in the first days after starting or after a dose increase. The steps that help are mostly about food: smaller meals, eating slowly, less greasy food, and stopping before you feel full. Our full plan is in managing nausea on Ozempic, Wegovy and other GLP-1s. If burps are the problem, see sulfur burps on GLP-1.

The hidden cost of nausea is protein. When food sounds awful, protein is usually the first thing to drop, and low protein plus fast weight loss means more muscle loss. Sharpy gives you one daily protein target, so on a queasy day you can see how close you are and fill the gap with easy foods like Greek yogurt, a protein shake or cottage cheese.

Call your prescriber right away if you cannot keep fluids down, vomit for more than a day, have severe belly pain that spreads to your back, or feel dizzy and dry. These can be signs of dehydration or problems like pancreatitis. Dose questions belong to your prescriber too; see the semaglutide dosage chart for what the label says.

The bottom line

Tradipitant is the first drug to show in a Phase 3 study that it can lower vomiting after a GLP-1 shot. That is real news, because stomach side effects are a top reason people quit these drugs. But Nereus is approved only for motion sickness, the GLP-1 data comes from a one-dose test, and the FDA has not weighed in. For now, food habits and a steady protein routine are still the main tools. Sharpy keeps that simple: one protein target, one 20-minute workout and one Shape Score a day, so you lose fat and not muscle.

Sources

• Vanda Pharmaceuticals announces positive results from Study 3601 of NEREUS (tradipitant) for prevention of GLP-1-induced vomiting, PR Newswire, October 27, 2026
• Vanda Pharmaceuticals reports positive results for tradipitant in preventing GLP-1 induced nausea and vomiting (Phase 2), PR Newswire, November 17, 2025
• NEREUS (tradipitant) prescribing information, DailyMed
• FDA approves tradipitant (Nereus) for the prevention of vomiting induced by motion, HCPLive, December 31, 2025
• The Thetis Study, ClinicalTrials.gov NCT07446439
• Vanda reports Phase III tradipitant trial data in GLP-1-associated vomiting, Clinical Trials Arena, October 28, 2026