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. 1842 · Search date 2026-07-24 · Methodology v0.6

Naproxen,
does it really help with Relief of primary dysmenorrhea?

30-Second Summary
B
Evidence Grade B · 70 · Safety caution
Naproxen works for short-term primary dysmenorrhea pain, but gastrointestinal and renal risks still matter
Gastrointestinal upset, ulceration or bleeding, kidney injury, fluid retention, and cardiovascular risk require caution. Anticoagulant use, prior gastrointestinal bleeding, kidney disease, and late pregnancy require professional review.
What the
research shows
Naproxen is rated B because it repeatedly reduced primary dysmenorrhea pain versus placebo. Twenty-one trials were included, and the 16 trials contributing to the drug-specific synthesis gave OR 3.67 (95% CI 2.94 to 4.58).
What the
ads claim
Marketing can imply a remedy for every menstrual or pelvic pain syndrome, whereas the evidence concerns short-term pain relief in primary dysmenorrhea without pelvic pathology.
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Useful facts when choosing a product

  • The Daniels trial distinguished 120 randomized participants from 85 efficacy completers.
  • Naproxen also appears in verdict 795 for osteoarthritis, a different indication.
Gap Measurement · Verdict 1842 · B 70
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Whether naproxen reduces primary dysmenorrhea pain. Daniels randomized 120, treated 101, and used 85 efficacy completers. Active-control naproxen produced SPID-8 of 12.0 versus 7.9 and TOTPAR-8 of 20.3 versus 13.5 compared with placebo, both P<0.001. The primary comparison was valdecoxib versus placebo; naproxen was secondary. Cochrane included 21 naproxen-placebo trials, of which 16 contributed to the drug-specific synthesis, OR 3.67 (95% CI 2.94 to 4.58). Decisive trials lasted only hours to days, and the Daniels analysis included 85 of 120 randomized participants, giving B1. verdict 795, which is B with 70 points, concerns osteoarthritis and was not transferred. verdict 1034, which is B with 70 points, verdict 857, which is B with 75 points, and verdict 1833, which is C with 55 points, concern other interventions.

02

Why this is classified as B (70)

P, R2, I1, E+, and B1 derive B with 70 points.

Counterpoint. New, worsening, or noncyclic pain requires assessment for a secondary cause.

Rejudgment record. Cross-check applied — Replicated placebo-controlled efficacy with B1 for hours-to-days duration and efficacy analysis of 85 among 120 randomized participants

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
Total pain relief over eight hoursBTOTPAR-8 was significantly higher than placebo.
Summed pain-intensity difference over eight hoursBSPID-8 was significantly higher than placebo.
Moderate or excellent dysmenorrhea reliefBMultiple trials repeatedly favored naproxen over placebo.

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
Daniels SE et al. 2005Randomized double-blind placebo- and active-controlled crossover trial85Commercial funding from Pharmacia within a drug-development programEight-hour SPID and TOTPAR pain reliefActive-control naproxen SPID-8 was 12.0 versus 7.9 and TOTPAR-8 was 20.3 versus 13.5; P<0.001 versus placebo, but secondaryDirect acute efficacy
Marjoribanks J et al. 2015Cochrane systematic review and meta-analysis21Academic Cochrane review; 59% of included trials commercially funded and 31% unreportedModerate or excellent pain reliefNaproxen-specific synthesis of 16 trials: OR 3.67 (95% CI 2.94 to 4.58); 21 was the included-trial countReplicated synthesis
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Receipt — 2 References

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

Daniels SE, Torri S, Desjardins PJ. Valdecoxib for treatment of primary dysmenorrhea. A randomized, double-blind comparison with placebo and naproxen. J Gen Intern Med. 2005;20(1):62-67. PMID: 15693930. DOI: 10.1111/j.1525-1497.2004.30052.x.
checked
Marjoribanks J, Ayeleke RO, Farquhar C, Proctor M. Nonsteroidal anti-inflammatory drugs for dysmenorrhoea. Cochrane Database Syst Rev. 2015;2015(7):CD001751. DOI: 10.1002/14651858.CD001751.pub3.
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

Naproxen x relief of primary dysmenorrhea Evidence Grade B card
[Chamgap] Naproxen x relief of primary dysmenorrhea — Evidence Grade B·70. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/womens/naproxen-primary-dysmenorrhea-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.