Tradipitant (NEREUS) to Prevent Vomiting From Motion Sickness in Adults

In December 2025 the Food and Drug Administration (FDA) approved tradipitant (NEREUS) to prevent vomiting related to motion sickness in adults.[1] Although tradipitant is a new treatment, the pivotal trials supporting approval were short in duration, did not show a reduction in nausea symptoms from motion sickness, and did not compare the new drug to other treatments, some of which are inexpensive and available over the counter. In July 2026 the retail price of 30 85-mg tradipitant capsules was $7,550 or higher.[2]

Motion sickness

Symptoms of motion sickness include nausea that may progress to vomiting, dizziness, excessive warmth, excessive sweating, rapid breathing, feeling faint or fainting when sitting or standing, and malaise.[3] Although not fully understood, acute motion sickness may be triggered by excessive real or virtual motion and is likely mediated by the autonomic nervous system, the part of the peripheral nervous system that regulates involuntary bodily functions.

Studies of people traveling in watercraft, buses or planes indicate that 8% to 13% experience nausea and 1% to 7% vomit or feel “quite ill” or worse. Children under 2 years do not typically experience motion sickness. If motion sickness develops in childhood, it typically peaks around age nine and declines thereafter.[4] Gene-wide association studies show that at least 35 genetic variations influence susceptibility to motion sickness, including several that increase susceptibility in women more than men.[5]

Acute treatment of motion sickness is often ineffective.[6] People with a history of motion four hours with peak wave heights of 0.3 to 2.5 meters. Participants completed a self-assessment every 30 minutes during the trip. The primary endpoint across both trials was incidence of vomiting, which occurred in 10% to 18% of the participants receiving tradipitant and 38% to 44% of those receiving placebo.

Neither study found a meaningful difference between the groups on a 5-point nausea scale (where 0 equals “no nausea” and 4 equals “very severe nausea”). The average nausea scale scores ranged from 2.2 to 2.4, with no significant differences between the three arms of either study.

Adverse effects were assessed across three trials: the two trials discussed above and a 12-month open-label safety trial. The open-label trial involved 382 participants with a history of motion sickness can consider preventive treatment in anticipation of travel. Treatments include over-the-counter medications and prescription topical patches.[7] A meta-analysis of small clinical trials of the prescription anticholinergic drug patch scopolamine (TRANSDERM SCOP and generics) showed that it reduced the occurrence of motion sickness by about 50% compared with placebo. Oral over-the-counter first-generation antihistamines (for example, dimenhydrinate and meclizine) are similarly effective.

Clinical trials of tradipitant

Tradipitant should be taken on an “empty stomach, at least 1 hour prior to or 2 hours after a full meal,” and about 60 minutes before an event that is expected to cause motion-induced vomiting, according to the prescribing information.[8] A single oral dose is 85 or 170 mg, which are also the maximum doses in a 24-hour period. Tradipitant is approved to prevent vomiting, not nausea, which is a more common symptom of motion sickness.[9]

Tradipitant inhibits the activity of substance P/neurokinin-1 receptors in the central and peripheral nervous systems, inhibition that animal studies show can prevent drug-induced emesis (vomiting).[10]

FDA approval was primarily based on two single-dose, randomized, placebo-controlled clinical trials, one with 365 participants and the other with 316 participants.[11] Participants had a mean age of 48 years; the range was 18 to 75 years. Participants in both trials were randomized equally into three groups: 85 mg of tradipitant, 170 mg of tradipitant, and placebo.

Tradipitant or placebo dosing occurred approximately 60 minutes before boat trips lasting two to four hours with peak wave heights of 0.3 to 2.5 meters. Participants completed a self-assessment every 30 minutes during the trip. The primary endpoint across both trials was incidence of vomiting, which occurred in 10% to 18% of the participants receiving tradipitant and 38% to 44% of those receiving placebo.

Neither study found a meaningful difference between the groups on a 5-point nausea scale (where 0 equals “no nausea” and 4 equals “very severe nausea”). The average nausea scale scores ranged from 2.2 to 2.4, with no significant differences between the three arms of either study.

Adverse effects were assessed across three trials: the two trials discussed above and a 12-month open-label safety trial. The open-label trial involved 382 participants with a history of motion sickness who were randomized to either 85-mg or 170-mg doses of tradipitant. Overall, three common adverse reactions were identified, all with an incidence of more than 5%: somnolence (drowsiness), headache and fatigue.[12] Across the three studies, these adverse effects were more frequent with the 170-mg dose of tradipitant (for example, a somnolence rate of 12% with 170 mg of tradipitant and 6% with placebo, and fatigue rates of 8% and 2%, respectively). Drowsiness is a common adverse effect of many other drugs used to prevent motion sickness, such as first-generation antihistamines.

The 12-month open-label safety trial limited tradipitant use to up to 90 daily as-needed doses for each participant. The median number of doses used was 18, with the majority (69%) of participants using fewer than 30 doses.

The FDA review noted that the safety of more tradipitant use remains uncertain because of the limitations of the clinical trials. Tradipitant has a half-life in the body of at least 28 hours. Other than studies in rodents, all animal toxicology testing (including for carcinogenesis) lasted six months or less.[13] The FDA is requiring the drug manufacturer to conduct a clinical pharmacology study to evaluate whether tradipitant and its byproducts cause liver impairment.

Tradipitant is only approved for adults; a clinical trial in children and adolescents is anticipated.[14]

What You Can Do

If you are an adult with a history of motion sickness from car, boat or other trips, established over-the-counter or prescription drugs may prevent or reduce the frequency and intensity of some symptoms. Nondrug methods that may help include focusing on stationary objects or the horizon, sitting or lying where there is less motion or fewer confusing visual stimuli (for example, the center of a cruise ship or the driving position or front seat of a car), minimizing reading and screen time, and using relaxation or distraction techniques such as mindful breathing or listening to music.[15],[16],[17]

Tradipitant does not prevent nausea. Clinical trials have not compared this drug with existing drug treatments for motion sickness. Its long-term safety and effectiveness are not known. For these reasons, Public Citizen’s Health Research Group has classified tradipitant as Do Not Use for Seven Years.
 

References

[1] Food and Drug Administration. Center for Drug Evaluation and Research. Advancing health through innovation: new drug therapy approvals 2025. January 2026. https://www.fda.gov/media/190705/download. Accessed June 29, 2026.

[2] GoodRx. Nereus, tradipitant. https://www.goodrx.com/nereus. Accessed July 13, 2026.

[3] Priesol AJ. Motion sickness. UpToDate. February 2026.

[4] Ibid.

[5] Hromatka BS, Tung JY, Kiefer AK, et al. Genetic variants associated with motion sickness point to roles for inner ear development, neurological processes and glucose homeostasis. Hum Mol Genet. 2015;24(9):2700-2708.

[6] Priesol AJ. Motion sickness. UpToDate. February 2026.

[7] Ibid.

[8] Vanda Pharmaceuticals. Label: tradipitant (NEREUS). December 2025. https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/220152Orig1s000lbl.pdf. Accessed July 6, 2026.

[9] Priesol AJ. Motion sickness. UpToDate. February 2026.

[10] Vanda Pharmaceuticals. Label: tradipitant (NEREUS). December 2025. https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/220152Orig1s000lbl.pdf. Accessed July 6, 2026.

[11] Ibid.

[12] Ibid.

[13] Food and Drug Administration. Center for Drug Evaluation and Research. Integrated review for NDA 220152: tradipitant (NEREUS). December 30, 2025. https://www.accessdata.fda.gov/drugsatfda_docs/nda/2026/220152Orig1s000IntegratedR.pdf. Accessed July 6, 2026.

[14] Food and Drug Administration. Center for Drug Evaluation and Research. Integrated review for NDA 220152: tradipitant (NEREUS). December 30, 2025. https://www.accessdata.fda.gov/drugsatfda_docs/nda/2026/220152Orig1s000IntegratedR.pdf. Accessed July 6, 2026.

[15] Ibid.

[16] Priesol AJ. Motion sickness. UpToDate. February 2026.

[17] Corliss J. Remedies for motion sickness: what works? Harvard Health Letter.  February 25, 2026. https://www.health.harvard.edu/preventive-care/remedies-for-motion-sickness-what-works. Accessed July 16, 2026.