Norgestrel side effects: what 1,350 FDA adverse event reports show

Norgestrel · Daily Oral Contraceptive · 25 reaction terms · 577 drug–reaction co-reports · data 2026-09-14

Drug class

Not stated in label

Brand names

Daily Oral Contraceptive

openFDA label

Who reports

1,350 reports · 22% serious · 1 with death outcome · 99% female

openFDA FAERS counts, all years, deduplication not applied

Used for

To prevent pregnancy

FDA label, Indications and Usage

Boxed warning

None in the current label

How to read this page. FAERS is a spontaneous-reporting system: counts are not incidence rates and a signal is not proof of causation. Each reaction below is run through an automated screen — is the term in the FDA label (known), in the indications (the disease being treated), an administrative/coding term, or none of these (unlabeled)? That screen is mechanical text matching, not a causality assessment. The 30 hand-written Bradford Hill assessments are on the causality assessment page. Not medical advice.

Causality screen of the 17 strongest signals

Labeled (related wording) 2Reporting / coding artifact 2Not in label — unassessed 13

What the badges mean

Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
Reporting / coding artifact An administrative, monitoring or exposure term (product issue, off-label use, 'test normal', overdose...). Not a biological reaction; a high PRR here reflects how reports are coded.
Not in label — unassessed Not found in the label text, not an artifact pattern. This is a genuine candidate for a formal causality assessment (Bradford Hill / WHO-UMC); it has NOT had one here.

Strongest disproportionality signals

Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only and flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 8 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.

Show: hide coding/lab/outcome terms hide indication terms unlabeled only hide PRR-only

Reaction	Reports	PRR 95% CI · ROR · χ²/p	EBGM EB05 · IC025	Label screen	Serious-only & strata	Trial cross-check
Dysmenorrhoea	52	62.0 47.5–81.0ROR 64.4 · χ² 3,050 / p <1e-300	60.5 EB05 47.9 · IC025 +4.8 3/3 methods agree	Not in label — unassessed	serious n=3 · 100% consumer	no trial data cached
Menstruation delayed	32	48.0 34.1–67.6ROR 49.1 · χ² 1,422 / p <1e-300	46.6 EB05 34.6 · IC025 +4.2 3/3 methods agree	Not in label — unassessed	serious n=1 · 100% consumer	no trial data cached
Menstruation irregular	51	29.9 22.8–39.2ROR 31.0 · χ² 1,395 / p <1e-300	29.6 EB05 23.4 · IC025 +4.1 3/3 methods agree	Not in label — unassessed	serious n=3 · 100% consumer	no trial data cached
Breast pain	16	23.3 14.3–38.0ROR 23.6 · χ² 320 / p 8e-72	22.7 EB05 14.7 · IC025 +3.0 3/3 methods agree	Labeled (related wording) related wording	–	no trial data cached
Amenorrhoea (missed periods)	23	21.4 14.3–32.1ROR 21.8 · χ² 427 / p 3e-95	21.0 EB05 14.7 · IC025 +3.2 3/3 methods agree	Not in label — unassessed	serious PRR 16.7 · 100% consumer	no trial data cached
Mood swings	39	19.0 14.0–25.9ROR 19.5 · χ² 648 / p 3e-143	18.8 EB05 14.3 · IC025 +3.4 3/3 methods agree	Not in label — unassessed	serious PRR 6.7 · 100% consumer	no trial data cached
Vaginal haemorrhage	40	14.6 10.8–19.8ROR 15.0 · χ² 494 / p 1e-109	14.4 EB05 10.9 · IC025 +3.1 3/3 methods agree	Not in label — unassessed	serious PRR 2.0 · 100% consumer	no trial data cached
Mood altered	24	13.7 9.2–20.4ROR 14.0 · χ² 271 / p 4e-61	13.2 EB05 9.0 · IC025 +2.8 3/3 methods agree	Not in label — unassessed	serious PRR 5.3 · 100% consumer	no trial data cached
Adverse drug reaction	68	11.8 9.4–14.9ROR 12.4 · χ² 665 / p 7e-147	11.6 EB05 9.4 · IC025 +3.0 3/3 methods agree	Reporting / coding artifact	serious PRR 2.6 · 100% consumer	no trial data cached
Acne	53	10.8 8.3–14.1ROR 11.2 · χ² 464 / p 4e-103	10.5 EB05 8.2 · IC025 +2.9 3/3 methods agree	Not in label — unassessed	serious PRR 2.6 · 100% consumer	no trial data cached
Crying	21	8.9 5.9–13.7ROR 9.1 · χ² 141 / p 1e-32	8.0 EB05 5.3 · IC025 +2.2 3/3 methods agree	Not in label — unassessed	serious PRR 22.8	no trial data cached
Drug ineffective for unapproved indication	31	8.6 6.1–12.2ROR 8.8 · χ² 202 / p 3e-46	8.0 EB05 5.8 · IC025 +2.3 3/3 methods agree	Reporting / coding artifact	100% consumer	no trial data cached
Anger	17	7.8 4.8–12.5ROR 7.9 · χ² 94 / p 2e-22	6.7 EB05 4.3 · IC025 +1.9 3/3 methods agree	Not in label — unassessed	serious PRR 3.9	no trial data cached
Emotional disorder	14	7.0 4.2–11.8ROR 7.1 · χ² 66 / p 2e-16	5.9 EB05 3.7 · IC025 +1.6 3/3 methods agree	Not in label — unassessed	–	no trial data cached
Depressed mood	20	5.9 3.8–9.1ROR 6.0 · χ² 77 / p 9e-19	5.2 EB05 3.6 · IC025 +1.6 3/3 methods agree	Not in label — unassessed	serious PRR 13.0	no trial data cached
Extra dose administered	11	4.3 2.4–7.7ROR 4.3 · χ² 25 / p 4e-7	3.7 EB05 2.2 · IC025 +0.9 3/3 methods agree	Not in label — unassessed	–	no trial data cached
Abortion spontaneous	11	4.2 2.4–7.7ROR 4.3 · χ² 24 / p 4e-7	3.7 EB05 2.2 · IC025 +0.9 3/3 methods agree	Labeled (related wording) related wording	serious PRR 10.2	no trial data cached

Trial evidence (ClinicalTrials.gov)

Trial cross-check not yet run for this drug (ClinicalTrials.gov pull covers the 800 most-reported drugs first).

Most frequently reported reactions

By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.

Reaction	Reports	PRR 95% CI · ROR · χ²/p	EBGM EB05 · IC025	Label screen	Serious-only & strata	Trial cross-check
Adverse drug reaction	68	11.8 9.4–14.9ROR 12.4 · χ² 665 / p 7e-147	11.6 EB05 9.4 · IC025 +3.0 3/3 methods agree	Reporting / coding artifact	serious PRR 2.6 · 100% consumer	no trial data cached
Acne	53	10.8 8.3–14.1ROR 11.2 · χ² 464 / p 4e-103	10.5 EB05 8.2 · IC025 +2.9 3/3 methods agree	Not in label — unassessed	serious PRR 2.6 · 100% consumer	no trial data cached
Dysmenorrhoea	52	62.0 47.5–81.0ROR 64.4 · χ² 3,050 / p <1e-300	60.5 EB05 47.9 · IC025 +4.8 3/3 methods agree	Not in label — unassessed	serious n=3 · 100% consumer	no trial data cached
Menstruation irregular	51	29.9 22.8–39.2ROR 31.0 · χ² 1,395 / p <1e-300	29.6 EB05 23.4 · IC025 +4.1 3/3 methods agree	Not in label — unassessed	serious n=3 · 100% consumer	no trial data cached
Vaginal haemorrhage	40	14.6 10.8–19.8ROR 15.0 · χ² 494 / p 1e-109	14.4 EB05 10.9 · IC025 +3.1 3/3 methods agree	Not in label — unassessed	serious PRR 2.0 · 100% consumer	no trial data cached
Mood swings	39	19.0 14.0–25.9ROR 19.5 · χ² 648 / p 3e-143	18.8 EB05 14.3 · IC025 +3.4 3/3 methods agree	Not in label — unassessed	serious PRR 6.7 · 100% consumer	no trial data cached
Menstruation delayed	32	48.0 34.1–67.6ROR 49.1 · χ² 1,422 / p <1e-300	46.6 EB05 34.6 · IC025 +4.2 3/3 methods agree	Not in label — unassessed	serious n=1 · 100% consumer	no trial data cached
Drug ineffective for unapproved indication	31	8.6 6.1–12.2ROR 8.8 · χ² 202 / p 3e-46	8.0 EB05 5.8 · IC025 +2.3 3/3 methods agree	Reporting / coding artifact	100% consumer	no trial data cached
Mood altered	24	13.7 9.2–20.4ROR 14.0 · χ² 271 / p 4e-61	13.2 EB05 9.0 · IC025 +2.8 3/3 methods agree	Not in label — unassessed	serious PRR 5.3 · 100% consumer	no trial data cached
Amenorrhoea (missed periods)	23	21.4 14.3–32.1ROR 21.8 · χ² 427 / p 3e-95	21.0 EB05 14.7 · IC025 +3.2 3/3 methods agree	Not in label — unassessed	serious PRR 16.7 · 100% consumer	no trial data cached
Crying	21	8.9 5.9–13.7ROR 9.1 · χ² 141 / p 1e-32	8.0 EB05 5.3 · IC025 +2.2 3/3 methods agree	Not in label — unassessed	serious PRR 22.8	no trial data cached
Depressed mood	20	5.9 3.8–9.1ROR 6.0 · χ² 77 / p 9e-19	5.2 EB05 3.6 · IC025 +1.6 3/3 methods agree	Not in label — unassessed	serious PRR 13.0	no trial data cached
Anger	17	7.8 4.8–12.5ROR 7.9 · χ² 94 / p 2e-22	6.7 EB05 4.3 · IC025 +1.9 3/3 methods agree	Not in label — unassessed	serious PRR 3.9	no trial data cached
Breast pain	16	23.3 14.3–38.0ROR 23.6 · χ² 320 / p 8e-72	22.7 EB05 14.7 · IC025 +3.0 3/3 methods agree	Labeled (related wording) related wording	–	no trial data cached
Emotional disorder	14	7.0 4.2–11.8ROR 7.1 · χ² 66 / p 2e-16	5.9 EB05 3.7 · IC025 +1.6 3/3 methods agree	Not in label — unassessed	–	no trial data cached

Unlabeled candidate signals

These flagged terms were not found in the FDA label text and do not match an artifact pattern. They are the pairs that would merit a structured assessment (temporality, dose-response, biological plausibility, consistency across databases, trial or cohort evidence). The screen has not done that; string-matching misses label wording, and a strong PRR can still be stimulated reporting, co-medication, or the disease itself.

Dysmenorrhoea — n=52, PRR 62.0
Menstruation delayed — n=32, PRR 48.0
Menstruation irregular — n=51, PRR 29.9
Amenorrhoea — n=23, PRR 21.4
Mood swings — n=39, PRR 19.0
Vaginal haemorrhage — n=40, PRR 14.6
Mood altered — n=24, PRR 13.7
Acne — n=53, PRR 10.8
Crying — n=21, PRR 8.9
Depressed mood — n=20, PRR 5.9

Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.

Common questions

What are the most reported side effects of Norgestrel?

In FDA FAERS, the most frequently co-reported reaction terms for Norgestrel are acne, dysmenorrhoea, menstruation irregular, vaginal haemorrhage, mood swings, menstruation delayed. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.

Does Norgestrel have an FDA boxed warning?

No. The FDA label retrieved for Norgestrel has no boxed warning; see the label's Warnings and Precautions for the recognised risks.

Do FAERS signals prove that Norgestrel causes these side effects?

No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.

Sources & methods

FDA label via openFDA (set ID 20477912-c1d6-4190-8f6e-00fb122134a1, effective 20260806; matched on openfda.generic_name.exact:"NORGESTREL")
Bayesian shrinkage measures computed offline over all 1,317,300 cached pairs: BCPNN information component (IC, with Norén closed-form IC025) and MGPS empirical-Bayes geometric mean (EBGM, EB05) with a two-component gamma prior fitted by maximum marginal likelihood (α₁=0.57, β₁=0.02, α₂=1.42, β₂=0.70, w=0.17); unstratified
FAERS pair statistics from the OpenPV build of 2026-09-14 (openFDA count= aggregation, field patient.drug.openfda.generic_name.exact, 25 reaction terms, min 3 co-reports); PRR/ROR with 95% CI, chi-square with Yates correction
Serious-only and stratified counts (serious:1, patient.patientsex, primarysource.qualification) from openFDA count queries; serious-only PRR uses the drug serious report total and the term global serious total (N_serious=11,882,979); strata shown only when n ≥ 20
Seriousness and sex counts from openFDA count=serious, patient.patientsex, seriousnessdeath

Page generated 2026-10-08. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.