Verdict No. 3049 · Search date 2026-09-08 · Methodology v1.0
A single 1-g preoperative dose of dried ginger powder,
does it really help with Reduction of nausea incidence within 24 postoperative hours?
30-Second Summary
C
Evidence Grade C · 46 · Safety caution
This verdict is limited to nausea incidence within 24 hours; vomiting and composite PONV are separate.
Caution. Fasting, aspiration risk, and anticoagulant or antiplatelet use require the anesthesia and surgical team's judgment; do not self-administer before surgery.
What the
research showsGrade C with 46 points. In a 120-person placebo trial of gynecologic laparotomy, a single preoperative 1-g dose of dried ginger powder was followed by nausea in 29/60 versus 40/60 participants over 24 hours (P=.042). Prespecification of nausea alone, the original between-group 95% CI, funding, and same-condition replication remain unverified.
research showsGrade C with 46 points. In a 120-person placebo trial of gynecologic laparotomy, a single preoperative 1-g dose of dried ginger powder was followed by nausea in 29/60 versus 40/60 participants over 24 hours (P=.042). Prespecification of nausea alone, the original between-group 95% CI, funding, and same-condition replication remain unverified.
What the
ads claimThe evidence does not support replacing prophylactic antiemetics or claiming prevention of vomiting, aspiration, or equal benefit in every surgery.
ads claimThe evidence does not support replacing prophylactic antiemetics or claiming prevention of vomiting, aspiration, or equal benefit in every surgery.
Useful facts when choosing a product
- This verdict applies only to the exact formulation, route, dose, duration, population, endpoint, and comparator shown above.
- Ginger food, powder, standardized extract, essential oil, topical products, and combination products are not interchangeable.
- Caution. Fasting, aspiration risk, and anticoagulant or antiplatelet use require the anesthesia and surgical team's judgment; do not self-administer before surgery.
Chamgap Semantic Classification Code
Permanent code issued
S.ginger.oral.postoperative-nausea-incidence.reduce.placeboSupplements and nutraceuticals > Ginger > Oral > Postoperative nausea incidence > Reduction claim > Placebo
Issued for 24-hour nausea incidence after major gynecologic laparotomy; vomiting and composite PONV are separate. The code identifies the intervention and claim; it never contains the evidence grade, score, or safety result.
Exact Claim Classification
These independent facets prevent evidence from different forms, routes, populations, effects, and comparators from being mixed.
| Intervention class | S · Supplement or nutraceutical |
|---|---|
| Canonical ingredient or intervention | Ginger |
| Source or part used | Rhizome of Zingiber officinale Roscoe |
| Formulation or processing | Two 500-mg dried ginger-powder capsules |
| Route | Oral |
| Dose | A single 1-g dose one hour preoperatively |
| Duration | One preoperative dose; 24-hour follow-up |
| Population | ASA I–II adult women undergoing elective major gynecologic laparotomy under general anesthesia |
| Effect or condition | Postoperative-nausea incidence reduction |
| Primary endpoint | Proportion reporting any nausea within 24 hours |
| Comparator | Appearance- and odor-matched lactose placebo with the same anesthesia and rescue care |
| Duplicate-detection key | ginger|two-500mg-dried-powder-capsules|oral|adult-women-major-gynecologic-laparotomy|postoperative-nausea-incidence-reduction|single-preoperative-dose |
Gap Measurement · Verdict 3049 · C 46
What the research actually shows
Two 2021 meta-analyses, surgery- and anesthesia-specific trials, and cesarean evidence were compared.
Why this is classified as C (46)
Direct placebo event counts are available, but prespecification, funding, the original confidence interval, and same-condition replication are unverified, with a small acute study; the result is C with 46 points.
Counterpoint. A cesarean-only Cochrane analysis did not establish a nausea benefit and rated certainty very low.
Rejudgment record. Independent Codex cross-check — One formulation, one route, one population, one claim, one principal endpoint and comparator
Scoring profile behind this grade
| Endpoint | P | Patient-reported treatment goal - the symptom is the goal |
| Replication | R1 | Single confirmatory trial |
| Independence | I1 | Mixed funding sources |
| Effect size | EX | The clinical size of the effect could not be judged |
| Precision | CX | No pooled confidence interval could be confirmed |
The scoring table and the verdict agree (C).
Cross-check — AI research and Codex final gate
AI was used for research and drafting. Blind grading, adversarial audit, and the methodology boundary rules were then reapplied before Codex performed the final evidence, grade, copy, and build checks. If a grade cannot be narrowed, both evidence positions and their reasons are published.
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| The efficacy of ginger in prevention of postoperative nausea and vomiting after major gynecologic surgery | The cited design, allocation, masking, endpoint hierarchy, and analysis limitations were independently checked. | 60 | Funding, product support, employee authorship, and declared conflicts were assessed separately. | The principal endpoint contract is preserved; secondary outcomes remain separate. | Verified estimates are preserved; missing confidence intervals or event counts were not invented. | Evidence weight reflects directness, formulation match, endpoint hierarchy, and reporting limitations. |
| The preventive and relieving effects of ginger on postoperative nausea and vomiting: A systematic review and meta-analysis of randomized controlled trials | The cited design, allocation, masking, endpoint hierarchy, and analysis limitations were independently checked. | 1,506 | Funding, product support, employee authorship, and declared conflicts were assessed separately. | The principal endpoint contract is preserved; secondary outcomes remain separate. | Verified estimates are preserved; missing confidence intervals or event counts were not invented. | Evidence weight reflects directness, formulation match, endpoint hierarchy, and reporting limitations. |
Receipt — 2 References
Of 2 cited sources, 1 had limited original-page access (blocked or summary-only) and were verified via index/summary, marked partial; the rest were verified at the original page. As of 2026-09-08.
Nanthakomon T, Pongrojpaw D. J Med Assoc Thai. 2006;89 Suppl 4:S130-S136. PMID: 17725149.
partialChen CC et al. Complement Ther Med. 2022;64:102812. PMID: 34700257. DOI: 10.1016/j.ctim.2021.102812. PROSPERO CRD42020220916.
checkedResearch and draft: AI used · Cross-check: blind grading and adversarial audit
Final verification and publication gate: Codex · Verification cutoff: 2026-09-08 · Corrections: none
Final verification and publication gate: Codex · Verification cutoff: 2026-09-08 · Corrections: none
Cite this verdict
[Chamgap] Ginger for Postoperative Nausea—A 24-Hour Signal After Gynecologic Laparotomy Lacks Clear Prespecification and Replication — Evidence Grade C·46. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/gut/oral-ginger-postoperative-nausea-incidence-within-24-hours/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.