Conclusion: We found high-certainty evidence that five single drugs (aprepitant, ramosetron, granisetron, dexamethasone, and ondansetron) reduce vomiting, and moderate-certainty evidence that two other single drugs (fosaprepitant and droperidol) probably reduce vomiting, compared to placebo. Four of the six substance classes (5-HT₃ receptor antagonists, D₂ receptor antagonists, NK₁ receptor antagonists, and corticosteroids) were thus represented by at least one drug with important benefit for prevention of vomiting. Combinations of drugs were generally more effective than the corresponding single drugs in
PubMed 33075160 ↗Ondansetron
The short answer. There isn't much data on Ondansetron yet — 4 mentions, 1 with a clear outcome — so treat these numbers as anecdotal. It is well studied — 204 meta-analyses on PubMed.
Out of 4 mentions; the other 75% didn't say how it went and aren't counted.
What Ondansetron does, according to users
Of the people who reported each effect, the share who said it got better.
What the research says
Systematic reviews and meta-analyses from PubMed, with their published conclusions.
3+ meta-analyses or systematic reviews and 10+ randomized controlled trials in humans. The grade measures how much human research exists — read the conclusions below for what it found.
Conclusion: For patients receiving HEC, various antiemetic regimens improved CIV and CIN control. For patients receiving MEC, administration of a 5HT3RA plus dexamethasone improved CIV control. Analysis of antiemetic safety was constrained by lack of data.
PubMed 35953731 ↗Conclusion: Ondansetron is the only intervention that revealed an effect on the cessation of vomiting, on preventing hospitalizations, and in reducing the need for intravenous rehydration. Ondansetron was also considered a safe intervention.
PubMed 32132152 ↗Conclusion: Within a minimally contextualized framework, as single agents, intravenous tropisetron and intravenous prochlorperazine are definitely among the most effective, intravenous metoclopramide and intravenous droperidol are possibly among the most effective, and oral ondansetron is definitely among the least effective; considering certain adverse reactions, intravenous metoclopramide, intravenous droperidol, and intravenous promethazine are definitely among the most harmful.
PubMed 40772912 ↗Dosage people report
Reported side effects
How often each side effect came up across all reports.
What users say
First-hand experiences, quoted verbatim. We show one positive and one negative where both exist.
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User data from public discussions; research from PubMed. Information only, not medical advice — talk to a doctor before starting, stopping or combining anything. Data updated October 3, 2026. How we rate