CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-24). The draft was written by AI, the existence of all 2 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 1823 · Search date 2026-07-24 · Methodology v0.6

Ibuprofen 400 mg,
does it really help with Single-dose pain relief for four to six hours in moderate or severe acute postoperative pain?

30-Second Summary
B
Evidence Grade B · 76 · Safety caution
A single 400-mg dose of ibuprofen provides meaningful relief for several hours after surgery
Adverse events after one dose were similar to placebo, but repeated use can cause gastrointestinal ulceration or bleeding, kidney injury, fluid retention, and cardiovascular harm. Avoid duplicate NSAIDs and seek professional advice when risk factors are present.
What the
research shows
A single 400-mg dose of ibuprofen provides clinically meaningful relief for moderate or severe postoperative pain and is graded B. The Cochrane review included 72 randomized double-blind placebo-controlled trials and 9,186 participants; among 6,475 participants contributing 400-mg data, the NNT for achieving at least 50% pain relief over four to six hours was 2.5 (95% CI 2.4 to 2.6). Pain is a patient-reported treatment target. The necessarily short single-dose design produces a B1 ceiling.
What the
ads claim
A strong single-dose analgesic effect does not establish faster surgical healing or safe long-term repeated use.
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Useful facts when choosing a product

  • The 400-mg Cochrane estimate concerns one oral dose and four to six hours of follow-up.
  • Verdict 1683, which is B with 68 points, concerns acute migraine, and verdict 857, which is B with 75 points, concerns primary dysmenorrhea. Their evidence was not pooled into postoperative pain.
  • Verdict 1407, which is D with 28 points, concerns prevention of delayed-onset muscle soreness and recovery of strength, a different endpoint.
Gap Measurement · Verdict 1823 · B 76
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

The Derry Cochrane review pooled 72 randomized double-blind placebo-controlled studies and 9,186 participants. The analyzed 400-mg dataset comprised 6,475 participants, with an NNT of 2.5 (2.4 to 2.6) for at least 50% relief over four to six hours. Kyselovic 2020 randomized and analyzed 351 participants; TOTPAR6 was 19.96 versus 8.27, P<0.001, meeting the placebo comparison for the primary efficacy endpoint. Sanofi funded the study and employees were coauthors.

02

Why this is classified as B (76)

The profile is P, R2, I1, E+, and B1. Multiple trials consistently achieved patient-important relief, with an NNT of 2.5 for achieving at least 50% pain relief over four to six hours, while the short single-dose design caps the derived grade at B with 76 points.

Counterpoint. Gastrointestinal ulcer or bleeding risk, kidney disease, cardiovascular disease, late pregnancy, and concurrent NSAIDs can change whether use is appropriate.

Rejudgment record. Cross-check applied — A precise NNT for a prespecified four-to-six-hour high-level pain response across many double-blind randomized trials

Scoring profile behind this grade
EndpointPPatient-reported treatment goal - the symptom is the goal
ReplicationR2Independently replicated across trials
IndependenceI1Mixed funding sources
Effect sizeE+Meets the clinically important threshold

The scoring table and the verdict agree (B).

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
At least 50% pain relief over four to six hours with one 400-mg doseBAmong 6,475 participants, the NNT for achieving at least 50% pain relief over four to six hours was 2.5.
Delay in postoperative rescue-medication useBMedian time to remedication with 400 mg was about 5.4 hours.
Improved six-hour total pain relief after dental surgeryBThe primary endpoint succeeded in a modern randomized trial.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Derry CJ et al. 2009 CochraneSystematic review of 72 randomized double-blind placebo-controlled trials6,475Oxford Pain Research Funds and NHS research-and-development support; mixed funding across component trialsAt least 50% total pain relief over four to six hoursFor achieving at least 50% pain relief over four to six hours with 400 mg, NNT was 2.5 (95% CI 2.4 to 2.6) and response rate was 54%; pooled primary efficacy outcome successful.Core large replicated evidence
Kyselovic J et al. 2020Randomized double-blind placebo- and active-controlled trial351Manufacturer funding from Sanofi with company employees as coauthorsTotal pain relief over six hours (TOTPAR6)Ibuprofen acid 19.96 versus placebo 8.27, P<0.001; placebo comparison for the primary efficacy endpoint successful.Modern formulation confirmation
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Receipt — 2 References

All 2 cited sources were verified for existence at the original page (as of 2026-07-24).

Derry C, Derry S, Moore RA, McQuay HJ. Single dose oral ibuprofen for acute postoperative pain in adults. Cochrane Database Syst Rev. 2009;2009(3):CD001548. PMID: 19588326. DOI: 10.1002/14651858.CD001548.pub2.
checked
Kyselovic J, Koscova E, Lampert A, Weiser T. A randomized, double-blind, placebo-controlled trial of ibuprofen lysinate in comparison to ibuprofen acid for acute postoperative dental pain. Pain Ther. 2020;9(1):249-259. PMID: 31912434. DOI: 10.1007/s40122-019-00148-1.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-24 · Corrections: none

Cite this verdict

Ibuprofen 400 mg x acute postoperative pain relief Evidence Grade B card
[Chamgap] Ibuprofen 400 mg x acute postoperative pain relief — Evidence Grade B·76. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/general/ibuprofen-400mg-acute-postoperative-pain-relief/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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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.