Flibanserin side effects: what 1,994 FDA adverse event reports show

Flibanserin · Addyi · 36 reaction terms · 2,048 drug–reaction co-reports · data 2026-09-14

Drug class

P-Glycoprotein Inhibitors

FDA label (mechanism-of-action class)

Brand names

Addyi

openFDA label

Who reports

1,994 reports · 5% serious · 0 with death outcome · 97% female

openFDA FAERS counts, all years, deduplication not applied

Used for

ADDYI is indicated for the treatment of women less than 65 years of age with acquired, generalized hypoactive sexual desire disorder (HSDD) as characterized by low sexual desire that causes marked distress or interpersonal difficulty and is not due to: • A co-existing medical or psychiatric condition, • Problems within the relationship, or • The effects of a medication or other drug substance.

FDA label, Indications and Usage

Boxed warning

HYPOTENSION and SYNCOPE IN CERTAIN SETTINGS Interaction with Alcohol The use of ADDYI and alcohol together close in time increases the risk of severe hypotension and syncope [see Warnings and Precautions (5.1) ]. Cou.

FDA 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 22 strongest signals

Labeled — boxed warning 2Labeled adverse reaction 6Reporting / coding artifact 9Not in label — unassessed 5

What the badges mean

Labeled — boxed warning The term (or its clinical synonym) appears in the FDA boxed warning: causality is regulator-recognised and considered serious.
Labeled adverse reaction The exact term appears in the label's warnings or adverse-reactions sections: a known, expected effect. The FAERS signal confirms the label rather than discovering anything.
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. 14 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
Middle insomnia	56	31.7 24.5–41.1ROR 32.6 · χ² 1,634 / p <1e-300	31.4 EB05 25.0 · IC025 +4.2 3/3 methods agree	Not in label — unassessed	serious PRR 41.6 · 96% consumer	no trial data cached
Adverse reaction	17	13.5 8.4–21.7ROR 13.6 · χ² 184 / p 3e-42	12.6 EB05 7.7 · IC025 +2.5 3/3 methods agree	Reporting / coding artifact	serious n=2	no trial data cached
Therapeutic response unexpected	56	13.1 10.1–17.0ROR 13.4 · χ² 614 / p 7e-136	12.9 EB05 10.2 · IC025 +3.1 3/3 methods agree	Reporting / coding artifact	serious PRR 51.5	no trial data cached
Presyncope (near-fainting)	27	11.7 8.1–17.1ROR 11.9 · χ² 255 / p 1e-57	11.1 EB05 7.7 · IC025 +2.7 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 6.3 · 89% consumer	no trial data cached
Adverse drug reaction	99	11.6 9.6–14.1ROR 12.2 · χ² 956 / p 3e-210	11.5 EB05 9.7 · IC025 +3.1 3/3 methods agree	Reporting / coding artifact	serious PRR 11.5 · 97% consumer	no trial data cached
Impaired driving ability	12	11.1 6.3–19.5ROR 11.2 · χ² 100 / p 6e-24	9.4 EB05 5.2 · IC025 +2.0 3/3 methods agree	Not in label — unassessed	serious PRR 27.8	no trial data cached
Drug ineffective for unapproved indication	50	9.4 7.2–12.4ROR 9.7 · χ² 370 / p 1e-82	9.0 EB05 7.0 · IC025 +2.7 3/3 methods agree	Reporting / coding artifact	serious PRR 14.3 · ♀ 73% (drug 97%) · 100% consumer	no trial data cached
Somnolence (drowsiness)	168	8.8 7.6–10.2ROR 9.5 · χ² 1,163 / p 3e-255	8.7 EB05 7.6 · IC025 +2.8 3/3 methods agree	Labeled — boxed warning exact term	serious PRR 6.1 · 94% consumer	no trial data cached
Intentional dose omission	21	8.1 5.3–12.4ROR 8.2 · χ² 123 / p 6e-29	7.1 EB05 4.8 · IC025 +2.1 3/3 methods agree	Reporting / coding artifact	100% consumer	no trial data cached
Therapeutic product effect decreased	32	7.6 5.4–10.7ROR 7.7 · χ² 177 / p 1e-40	7.0 EB05 5.1 · IC025 +2.2 3/3 methods agree	Reporting / coding artifact	serious PRR 5.3 · 91% consumer	no trial data cached
Dizziness	331	7.0 6.3–7.7ROR 8.2 · χ² 1,735 / p <1e-300	6.9 EB05 6.3 · IC025 +2.6 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 6.4 · 94% consumer	no trial data cached
Product use in unapproved indication	154	6.6 5.7–7.7ROR 7.1 · χ² 739 / p 4e-163	6.5 EB05 5.7 · IC025 +2.4 3/3 methods agree	Reporting / coding artifact	serious PRR 8.7 · 95% consumer	no trial data cached
Vertigo (spinning dizziness)	34	5.9 4.2–8.2ROR 6.0 · χ² 133 / p 5e-31	5.5 EB05 4.1 · IC025 +1.9 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 8.1 · 79% consumer	no trial data cached
Mood altered	15	5.8 3.5–9.6ROR 5.8 · χ² 55 / p 6e-14	5.0 EB05 3.2 · IC025 +1.5 3/3 methods agree	Not in label — unassessed	–	no trial data cached
Insomnia (trouble sleeping)	142	5.6 4.8–6.6ROR 6.0 · χ² 539 / p 2e-119	5.5 EB05 4.8 · IC025 +2.2 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 5.0 · 91% consumer	no trial data cached
Abnormal dreams	13	4.9 2.9–8.5ROR 4.9 · χ² 37 / p 7e-10	4.2 EB05 2.7 · IC025 +1.2 3/3 methods agree	Labeled adverse reaction exact term	–	no trial data cached
Drug ineffective (drug did not work)	561	4.5 4.2–4.8ROR 5.8 · χ² 1,615 / p <1e-300	4.5 EB05 4.2 · IC025 +2.0 3/3 methods agree	Reporting / coding artifact	serious PRR 1.8 · 99% consumer	no trial data cached
Feeling abnormal	101	4.4 3.7–5.3ROR 4.6 · χ² 267 / p 3e-60	4.3 EB05 3.7 · IC025 +1.8 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 7.5 · 94% consumer	no trial data cached
Sedation	10	4.0 2.2–7.5ROR 4.1 · χ² 20 / p 4e-6	3.5 EB05 2.1 · IC025 +0.7 3/3 methods agree	Labeled — boxed warning exact term	serious PRR 6.3	no trial data cached
Anger	13	4.0 2.3–6.9ROR 4.0 · χ² 27 / p 1e-7	3.6 EB05 2.3 · IC025 +0.9 3/3 methods agree	Not in label — unassessed	–	no trial data cached
Adverse event	31	3.5 2.5–5.0ROR 3.6 · χ² 54 / p 9e-14	3.4 EB05 2.5 · IC025 +1.2 3/3 methods agree	Reporting / coding artifact	serious PRR 2.9 · 100% consumer	no trial data cached
Irritability	20	3.5 2.3–5.4ROR 3.5 · χ² 33 / p 4e-9	3.3 EB05 2.3 · IC025 +1.0 3/3 methods agree	Not in label — unassessed	serious PRR 3.5 · 95% consumer	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
Drug ineffective (drug did not work)	561	4.5 4.2–4.8ROR 5.8 · χ² 1,615 / p <1e-300	4.5 EB05 4.2 · IC025 +2.0 3/3 methods agree	Reporting / coding artifact	serious PRR 1.8 · 99% consumer	no trial data cached
Dizziness	331	7.0 6.3–7.7ROR 8.2 · χ² 1,735 / p <1e-300	6.9 EB05 6.3 · IC025 +2.6 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 6.4 · 94% consumer	no trial data cached
Somnolence (drowsiness)	168	8.8 7.6–10.2ROR 9.5 · χ² 1,163 / p 3e-255	8.7 EB05 7.6 · IC025 +2.8 3/3 methods agree	Labeled — boxed warning exact term	serious PRR 6.1 · 94% consumer	no trial data cached
Product use in unapproved indication	154	6.6 5.7–7.7ROR 7.1 · χ² 739 / p 4e-163	6.5 EB05 5.7 · IC025 +2.4 3/3 methods agree	Reporting / coding artifact	serious PRR 8.7 · 95% consumer	no trial data cached
Insomnia (trouble sleeping)	142	5.6 4.8–6.6ROR 6.0 · χ² 539 / p 2e-119	5.5 EB05 4.8 · IC025 +2.2 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 5.0 · 91% consumer	no trial data cached
Feeling abnormal	101	4.4 3.7–5.3ROR 4.6 · χ² 267 / p 3e-60	4.3 EB05 3.7 · IC025 +1.8 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 7.5 · 94% consumer	no trial data cached
Adverse drug reaction	99	11.6 9.6–14.1ROR 12.2 · χ² 956 / p 3e-210	11.5 EB05 9.7 · IC025 +3.1 3/3 methods agree	Reporting / coding artifact	serious PRR 11.5 · 97% consumer	no trial data cached
Therapeutic response unexpected	56	13.1 10.1–17.0ROR 13.4 · χ² 614 / p 7e-136	12.9 EB05 10.2 · IC025 +3.1 3/3 methods agree	Reporting / coding artifact	serious PRR 51.5	no trial data cached
Middle insomnia	56	31.7 24.5–41.1ROR 32.6 · χ² 1,634 / p <1e-300	31.4 EB05 25.0 · IC025 +4.2 3/3 methods agree	Not in label — unassessed	serious PRR 41.6 · 96% consumer	no trial data cached
Drug ineffective for unapproved indication	50	9.4 7.2–12.4ROR 9.7 · χ² 370 / p 1e-82	9.0 EB05 7.0 · IC025 +2.7 3/3 methods agree	Reporting / coding artifact	serious PRR 14.3 · ♀ 73% (drug 97%) · 100% consumer	no trial data cached
Vertigo (spinning dizziness)	34	5.9 4.2–8.2ROR 6.0 · χ² 133 / p 5e-31	5.5 EB05 4.1 · IC025 +1.9 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 8.1 · 79% consumer	no trial data cached
Therapeutic product effect decreased	32	7.6 5.4–10.7ROR 7.7 · χ² 177 / p 1e-40	7.0 EB05 5.1 · IC025 +2.2 3/3 methods agree	Reporting / coding artifact	serious PRR 5.3 · 91% consumer	no trial data cached
Adverse event	31	3.5 2.5–5.0ROR 3.6 · χ² 54 / p 9e-14	3.4 EB05 2.5 · IC025 +1.2 3/3 methods agree	Reporting / coding artifact	serious PRR 2.9 · 100% consumer	no trial data cached
Presyncope (near-fainting)	27	11.7 8.1–17.1ROR 11.9 · χ² 255 / p 1e-57	11.1 EB05 7.7 · IC025 +2.7 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 6.3 · 89% consumer	no trial data cached
Intentional dose omission	21	8.1 5.3–12.4ROR 8.2 · χ² 123 / p 6e-29	7.1 EB05 4.8 · IC025 +2.1 3/3 methods agree	Reporting / coding artifact	100% consumer	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.

Middle insomnia — n=56, PRR 31.7
Irritability — n=20, PRR 3.5

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 Flibanserin?

In FDA FAERS, the most frequently co-reported reaction terms for Flibanserin are dizziness, somnolence, insomnia, feeling abnormal, middle insomnia, vertigo. 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 Flibanserin have an FDA boxed warning?

Yes. The current FDA label carries a boxed warning: HYPOTENSION and SYNCOPE IN CERTAIN SETTINGS Interaction with Alcohol The use of ADDYI and alcohol together close in time increases the risk of severe hypotension and syncope [see Warnings and Precautions (5.1) ]. Cou.

Do FAERS signals prove that Flibanserin 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 3819daf3-e935-2c53-c527-e1d57922f394, effective 20251222; matched on openfda.generic_name.exact:"FLIBANSERIN")
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, 36 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.