CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-19). The draft was written by AI, the existence of all 3 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 653 · Search date 2026-07-19 · Methodology v0.6

Dienogest,
does it really help with Reduction of endometriosis-associated pelvic pain and dysmenorrhea?

30-Second Summary
B
Evidence Grade B · 66 · Safety unknown
Pain relief is established, but it is not the same as curing lesions or improving pregnancy success
What the
research shows
Dienogest is rated B because randomized trials repeatedly show direct reductions in endometriosis-associated pelvic pain and dysmenorrhea. In a 198-participant placebo-controlled 12-week trial, the between-group difference in pain reduction was 12.3 mm on a visual analogue scale. In a 255-participant Chinese phase 3 trial over 24 weeks, pain fell 24.54 mm more than with placebo. Pain is directly important to patients, but it is subjectively measured, pivotal studies involved Bayer, and active-comparator and long-term evidence is heterogeneous. Symptom suppression is not lesion cure or proven fertility benefit; irregular bleeding, possible bone loss, and mood changes remain separate safety issues.
What the
ads claim
Marketing can turn pain relief into lesion cure, permanent prevention of recurrence, or increased pregnancy success. Dienogest suppresses symptoms during hormonal treatment; it has not been shown to permanently eradicate disease or improve every reproductive outcome.
*

Useful facts when choosing a product

  • Dienogest is an oral progestin used to treat endometriosis and is generally taken continuously each day according to the prescription and product information.
  • Irregular bleeding, spotting, or amenorrhea is common, and headache, breast discomfort, weight change, and mood symptoms can occur.
  • Possible bone-mineral-density changes should be considered during longer use, especially in adolescents and in patients with additional bone risk.
  • It should not be used during pregnancy, and contraindications such as severe liver disease, hormone-dependent tumors, and relevant thrombotic conditions must be reviewed before prescribing.
Gap Measurement · Verdict 653 · B 66
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Strowitzki and colleagues randomized 198 women with laparoscopically confirmed endometriosis and pelvic-pain scores of at least 30 mm to dienogest 2 mg or placebo for 12 weeks. VAS scores fell 27.4 and 15.1 mm, respectively, a 12.3-mm between-group difference. Lang and colleagues randomized 255 Chinese women for 24 weeks and reported an adjusted mean pain difference of -24.54 mm versus placebo. A 2015 systematic review of nine randomized trials concluded that dienogest reduced pelvic pain versus placebo and provided symptom control similar to GnRH agonists, while noting a lack of comparisons with less expensive first-line progestins and combined oral contraceptives.

02

Why this is classified as B (66)

Patient-centered pain outcomes improved repeatedly in 12- and 24-week placebo-controlled trials, supporting B. Subjective measurement, manufacturer involvement, heterogeneity in long-term and comparator data, and lack of proof for lesion cure or pregnancy success limit the score to 66. Bleeding, bone, and mood effects are separate safety concerns.

Counterpoint. It is a meaningful option when pain impairs function and quality of life. Benefits and adverse effects should be reassessed over time alongside pregnancy plans, bone risk, bleeding pattern, and mood symptoms.

Rejudgment record. New verdict — Accepted repeated patient-centered pelvic-pain reduction in separate placebo-controlled randomized trials, while accounting for subjective measurement, manufacturer involvement, heterogeneous long-term and comparator evidence, and no proof of lesion cure or pregnancy success

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
Reduction of endometriosis-associated pelvic pain and dysmenorrheaBSeparate placebo-controlled trials repeatedly improved direct pain outcomes, with subjective measurement and manufacturer involvement.
Permanent lesion cure and improved pregnancy success?Symptom-suppression trials do not establish this composite claim, and direct reproductive-outcome evidence is insufficient.
Irregular bleeding, bone-mineral-density change, and mood effects?This is a separate safety subclaim requiring individualized risk assessment rather than an efficacy claim.

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
Study 1Multicenter randomized double-blind placebo-controlled trial198Schering/Bayer development program with company-affiliated authorsTwelve-week pelvic-pain VAS change and rescue-analgesic use compositeVAS reduction was 27.4 mm versus 15.1 mm, favoring dienogest by 12.3 mm.Pivotal direct pain-endpoint trial with manufacturer involvement
Study 2Multicenter randomized double-blind placebo-controlled phase 3 trial255Bayer AG involvement and company-affiliated authorsChange in endometriosis-associated pelvic-pain VAS at week 24Adjusted mean difference versus placebo was -24.54 mm (95% CI -29.93 to -19.15).Regional randomized replication on a direct pain endpoint
Study 3Systematic review of randomized trials9Academic review; included trials may have sponsor concentrationPelvic pain, lesions, and symptom control versus comparatorsDienogest reduced pain versus placebo and was similar to GnRH agonists, but comparisons with less expensive first-line hormonal treatments were absent.Synthesis confirming consistency and comparator gaps
§

Receipt — 3 References

All 3 cited sources were verified for existence at the original page (as of 2026-07-19).

Strowitzki T, Faustmann T, Gerlinger C, Seitz C. Dienogest in the treatment of endometriosis-associated pelvic pain: a 12-week, randomized, double-blind, placebo-controlled study. Eur J Obstet Gynecol Reprod Biol. 2010;151:193-198. PMID: 20444534. DOI: 10.1016/j.ejogrb.2010.04.002.
checked
Lang J, Yu Q, Zhang S, et al. Dienogest for treatment of endometriosis in Chinese women: a placebo-controlled, randomized, double-blind phase 3 study. J Womens Health. 2018;27:148-155. PMID: 29083258. DOI: 10.1089/jwh.2017.6399.
checked
Andres MP, Lopes LA, Baracat EC, Podgaec S. Dienogest in the treatment of endometriosis: systematic review. Arch Gynecol Obstet. 2015;292:523-529. PMID: 25749349. DOI: 10.1007/s00404-015-3681-6.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-19 · Corrections: none

Cite this verdict

Dienogest x reduction of endometriosis-associated pelvic pain and dysmenorrhea Evidence Grade B card
[Chamgap] Dienogest x reduction of endometriosis-associated pelvic pain and dysmenorrhea — Evidence Grade B·66. 3 cited sources checked. Source: https://chamgap.com/en/verdicts/womens/dienogest-endometriosis-pelvic-pain-dysmenorrhea/ · CC BY 4.0

CC 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.