Clascoterone side effects: what 1,418 FDA adverse event reports show

Clascoterone · Winlevi · 21 reaction terms · 1,457 drug–reaction co-reports · data 2026-09-14

Drug class

Androgen Receptor Inhibitor

FDA label (Established Pharmacologic Class) · compare the class

Brand names

Winlevi

openFDA label

Who reports

1,418 reports · 5% serious · 0 with death outcome · 90% female

openFDA FAERS counts, all years, deduplication not applied

Used for

WINLEVI (clascoterone) cream is an androgen receptor inhibitor indicated for the topical treatment of acne vulgaris in patients 12 years of age and older. WINLEVI (clascoterone) cream is an androgen receptor inhibitor indicated for the topical treatment of acne vulgaris in patients 12 years of age and older. ( 1 )

FDA label, Indications and Usage

What it is

WINLEVI (clascoterone) cream contains clascoterone, an androgen receptor inhibitor, in a cream base for topical dermatologic use. WINLEVI cream is a white to almost white cream.

FDA label, Description section

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 15 strongest signals

Labeled (related wording) 1Likely indication confounding 1Reporting / coding artifact 9Not in label — unassessed 4

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.
Likely indication confounding The term appears in the label's indications: reports probably describe the disease being treated (or its progression), not a drug effect. Classic confounding by indication.
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. 6 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
Product use complaint	286	278.0 250.4–308.7ROR 348.0 · χ² 77,251 / p <1e-300	268.0 EB05 242.9 · IC025 +7.3 3/3 methods agree	Reporting / coding artifact	serious n=1 · 88% consumer	no trial data cached
Poor quality product administered	84	122.5 99.5–150.9ROR 130.2 · χ² 9,924 / p <1e-300	118.3 EB05 98.5 · IC025 +5.8 3/3 methods agree	Not in label — unassessed	serious n=1 · 93% consumer	no trial data cached
Product physical issue	78	58.1 46.8–72.1ROR 61.4 · χ² 4,307 / p <1e-300	57.1 EB05 47.2 · IC025 +5.0 3/3 methods agree	Reporting / coding artifact	91% consumer	no trial data cached
Product storage error	333	57.1 52.0–62.8ROR 74.4 · χ² 18,311 / p <1e-300	56.7 EB05 51.8 · IC025 +5.5 3/3 methods agree	Reporting / coding artifact	serious PRR 20.0	no trial data cached
Therapy cessation	86	24.9 20.3–30.6ROR 26.5 · χ² 1,953 / p <1e-300	24.8 EB05 20.7 · IC025 +4.1 3/3 methods agree	Reporting / coding artifact	serious PRR 14.1 · 85% consumer	no trial data cached
Product use issue	153	12.1 10.4–14.1ROR 13.5 · χ² 1,561 / p <1e-300	12.0 EB05 10.5 · IC025 +3.3 3/3 methods agree	Reporting / coding artifact	99% consumer	no trial data cached
Expired product administered	22	9.8 6.5–14.9ROR 9.9 · χ² 166 / p 4e-38	8.9 EB05 5.9 · IC025 +2.3 3/3 methods agree	Reporting / coding artifact	86% consumer	no trial data cached
Amenorrhoea (missed periods)	11	9.7 5.4–17.6ROR 9.8 · χ² 78 / p 6e-19	7.9 EB05 4.4 · IC025 +1.8 3/3 methods agree	Not in label — unassessed	serious PRR 22.1	no trial data cached
Product dose omission issue	184	9.6 8.4–10.9ROR 10.8 · χ² 1,420 / p <1e-300	9.4 EB05 8.3 · IC025 +3.0 3/3 methods agree	Reporting / coding artifact	serious PRR 17.1 · 95% consumer	no trial data cached
Acne	46	8.9 6.7–11.9ROR 9.2 · χ² 317 / p 3e-71	8.5 EB05 6.5 · IC025 +2.6 3/3 methods agree	Likely indication confounding term in indications; also in warnings	serious PRR 41.6 · 74% consumer	no trial data cached
Skin irritation	23	7.4 4.9–11.1ROR 7.5 · χ² 121 / p 1e-28	6.6 EB05 4.6 · IC025 +2.0 3/3 methods agree	Labeled (related wording) related wording	78% consumer	no trial data cached
Product quality issue	67	7.4 5.8–9.3ROR 7.7 · χ² 364 / p 2e-81	7.1 EB05 5.7 · IC025 +2.4 3/3 methods agree	Reporting / coding artifact	88% consumer	no trial data cached
Therapy interrupted	21	4.5 2.9–6.9ROR 4.6 · χ² 54 / p 1e-13	4.1 EB05 2.9 · IC025 +1.3 3/3 methods agree	Reporting / coding artifact	serious PRR 5.3 · 81% consumer	no trial data cached
Circumstance or information capable of leading to medication error	10	4.4 2.4–8.2ROR 4.4 · χ² 23 / p 8e-7	3.7 EB05 2.2 · IC025 +0.8 3/3 methods agree	Not in label — unassessed	–	no trial data cached
Skin burning sensation	19	4.0 2.5–6.2ROR 4.0 · χ² 39 / p 2e-10	3.6 EB05 2.5 · IC025 +1.1 3/3 methods agree	Not in label — unassessed	serious PRR 35.0	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
Product storage error	333	57.1 52.0–62.8ROR 74.4 · χ² 18,311 / p <1e-300	56.7 EB05 51.8 · IC025 +5.5 3/3 methods agree	Reporting / coding artifact	serious PRR 20.0	no trial data cached
Product use complaint	286	278.0 250.4–308.7ROR 348.0 · χ² 77,251 / p <1e-300	268.0 EB05 242.9 · IC025 +7.3 3/3 methods agree	Reporting / coding artifact	serious n=1 · 88% consumer	no trial data cached
Product dose omission issue	184	9.6 8.4–10.9ROR 10.8 · χ² 1,420 / p <1e-300	9.4 EB05 8.3 · IC025 +3.0 3/3 methods agree	Reporting / coding artifact	serious PRR 17.1 · 95% consumer	no trial data cached
Product use issue	153	12.1 10.4–14.1ROR 13.5 · χ² 1,561 / p <1e-300	12.0 EB05 10.5 · IC025 +3.3 3/3 methods agree	Reporting / coding artifact	99% consumer	no trial data cached
Therapy cessation	86	24.9 20.3–30.6ROR 26.5 · χ² 1,953 / p <1e-300	24.8 EB05 20.7 · IC025 +4.1 3/3 methods agree	Reporting / coding artifact	serious PRR 14.1 · 85% consumer	no trial data cached
Poor quality product administered	84	122.5 99.5–150.9ROR 130.2 · χ² 9,924 / p <1e-300	118.3 EB05 98.5 · IC025 +5.8 3/3 methods agree	Not in label — unassessed	serious n=1 · 93% consumer	no trial data cached
Product physical issue	78	58.1 46.8–72.1ROR 61.4 · χ² 4,307 / p <1e-300	57.1 EB05 47.2 · IC025 +5.0 3/3 methods agree	Reporting / coding artifact	91% consumer	no trial data cached
Product quality issue	67	7.4 5.8–9.3ROR 7.7 · χ² 364 / p 2e-81	7.1 EB05 5.7 · IC025 +2.4 3/3 methods agree	Reporting / coding artifact	88% consumer	no trial data cached
Acne	46	8.9 6.7–11.9ROR 9.2 · χ² 317 / p 3e-71	8.5 EB05 6.5 · IC025 +2.6 3/3 methods agree	Likely indication confounding term in indications; also in warnings	serious PRR 41.6 · 74% consumer	no trial data cached
Skin irritation	23	7.4 4.9–11.1ROR 7.5 · χ² 121 / p 1e-28	6.6 EB05 4.6 · IC025 +2.0 3/3 methods agree	Labeled (related wording) related wording	78% consumer	no trial data cached
Expired product administered	22	9.8 6.5–14.9ROR 9.9 · χ² 166 / p 4e-38	8.9 EB05 5.9 · IC025 +2.3 3/3 methods agree	Reporting / coding artifact	86% consumer	no trial data cached
Therapy interrupted	21	4.5 2.9–6.9ROR 4.6 · χ² 54 / p 1e-13	4.1 EB05 2.9 · IC025 +1.3 3/3 methods agree	Reporting / coding artifact	serious PRR 5.3 · 81% consumer	no trial data cached
Skin burning sensation	19	4.0 2.5–6.2ROR 4.0 · χ² 39 / p 2e-10	3.6 EB05 2.5 · IC025 +1.1 3/3 methods agree	Not in label — unassessed	serious PRR 35.0	no trial data cached
Accidental exposure to product	11	1.6 0.9–2.9ROR 1.6 · χ² 2 / p 0.074	1.6 EB05 1.0 · IC025 -0.4 PRR-only: not supported by EBGM or IC	Reporting / coding artifact	–	no trial data cached
Amenorrhoea (missed periods)	11	9.7 5.4–17.6ROR 9.8 · χ² 78 / p 6e-19	7.9 EB05 4.4 · IC025 +1.8 3/3 methods agree	Not in label — unassessed	serious PRR 22.1	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.

Poor quality product administered — n=84, PRR 122.5

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 Clascoterone?

In FDA FAERS, the most frequently co-reported reaction terms for Clascoterone are poor quality product administered, acne, skin irritation, skin burning sensation, amenorrhoea. 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 Clascoterone have an FDA boxed warning?

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

Do FAERS signals prove that Clascoterone 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 1673a84b-7f5c-47ab-a99c-1e3db21a6a09, effective 20250102; matched on openfda.generic_name.exact:"CLASCOTERONE")
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, 21 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.