Follitropin Alfa side effects: what 2,009 FDA adverse event reports show

Follitropin Alfa · Gonal-F · 42 reaction terms · 1,134 drug–reaction co-reports · data 2026-09-14

Drug class

Gonadotropin

FDA label, Indications wording

Brand names

Gonal-F

openFDA label

Who reports

2,009 reports · 83% serious · 30 with death outcome · 96% female

openFDA FAERS counts, all years, deduplication not applied

Used for

GONAL-f is indicated for: GONAL-f is a gonadotropin indicated for: Women: Induction of ovulation and pregnancy in oligo-anovulatory infertile women for whom the cause of infertility is functional and not due to primary ovarian failure. ( 1.1 ) Development of multiple follicles in ovulatory infertile women as part of Assisted Reproductive Technology (ART) cycles.

FDA label, Indications and Usage

What it is

Follitropin alfa, a gonadotropin [human follicle stimulating hormone (hFSH)], is a glycoprotein hormone produced by recombinant DNA technology in a Chinese Hamster Ovary (CHO) cell line. It has a dimeric structure containing two glycoprotein subunits (alpha and beta).

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 19 strongest signals

Labeled adverse reaction 5Labeled (related wording) 3Likely indication confounding 1Reporting / coding artifact 6Not in label — unassessed 4

What the badges mean

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.
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. 23 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
Ascites	223	79.7 70.4–90.3ROR 89.6 · χ² 17,149 / p <1e-300	78.6 EB05 70.3 · IC025 +5.9 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 55.4 · 93% clinician	no trial data cached
Abortion spontaneous	123	32.0 27.0–38.0ROR 34.0 · χ² 3,659 / p <1e-300	31.8 EB05 27.3 · IC025 +4.5 3/3 methods agree	Labeled (related wording) related wording	serious PRR 22.2	no trial data cached
Ovarian cyst	25	26.0 17.6–38.4ROR 26.3 · χ² 575 / p 2e-127	25.5 EB05 18.1 · IC025 +3.5 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 20.9	no trial data cached
Caesarean section	27	24.0 16.5–34.9ROR 24.3 · χ² 572 / p 1e-126	23.6 EB05 17.0 · IC025 +3.4 3/3 methods agree	Not in label — unassessed	serious PRR 17.0	no trial data cached
Drug exposure during pregnancy	58	17.6 13.6–22.7ROR 18.1 · χ² 890 / p 7e-196	17.4 EB05 14.0 · IC025 +3.5 3/3 methods agree	Reporting / coding artifact	serious PRR 13.5	no trial data cached
Pregnancy	34	17.6 12.6–24.5ROR 17.9 · χ² 515 / p 3e-114	17.3 EB05 12.9 · IC025 +3.3 3/3 methods agree	Likely indication confounding term in indications; also in warnings	serious PRR 17.2	no trial data cached
Pleural effusion	76	13.0 10.5–16.3ROR 13.5 · χ² 834 / p 1e-183	12.9 EB05 10.6 · IC025 +3.2 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 9.3 · 96% clinician	no trial data cached
Drug level decreased	12	12.3 7.0–21.6ROR 12.3 · χ² 113 / p 1e-26	10.6 EB05 5.8 · IC025 +2.1 3/3 methods agree	Reporting / coding artifact	serious PRR 10.4	no trial data cached
Abdominal pain lower	29	11.9 8.3–17.2ROR 12.1 · χ² 280 / p 4e-63	11.4 EB05 8.0 · IC025 +2.7 3/3 methods agree	Labeled (related wording) related wording	serious PRR 12.4 · 96% clinician	no trial data cached
Abdominal distension (bloating)	116	11.7 9.8–13.9ROR 12.3 · χ² 1,124 / p 1e-246	11.5 EB05 9.8 · IC025 +3.2 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 12.8	no trial data cached
Inappropriate schedule of drug administration	80	11.6 9.3–14.4ROR 12.0 · χ² 765 / p 1e-168	11.4 EB05 9.4 · IC025 +3.1 3/3 methods agree	Reporting / coding artifact	serious PRR 1.0 · 99% clinician	no trial data cached
Pelvic pain	17	9.8 6.1–15.7ROR 9.8 · χ² 125 / p 2e-29	8.5 EB05 5.4 · IC025 +2.1 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 10.1	no trial data cached
Premature baby	24	8.3 5.6–12.4ROR 8.4 · χ² 147 / p 4e-34	7.4 EB05 5.2 · IC025 +2.2 3/3 methods agree	Not in label — unassessed	serious PRR 5.8 · ♀ 55% (drug 96%)	no trial data cached
Generalised tonic-clonic seizure	11	7.0 3.9–12.7ROR 7.1 · χ² 51 / p 5e-13	5.6 EB05 3.3 · IC025 +1.5 3/3 methods agree	Not in label — unassessed	serious PRR 4.9	no trial data cached
Maternal exposure during pregnancy	50	5.9 4.5–7.8ROR 6.0 · χ² 200 / p 9e-46	5.6 EB05 4.4 · IC025 +2.0 3/3 methods agree	Reporting / coding artifact	serious PRR 4.6	no trial data cached
Vaginal haemorrhage	23	5.6 3.8–8.5ROR 5.7 · χ² 83 / p 3e-20	5.1 EB05 3.6 · IC025 +1.7 3/3 methods agree	Not in label — unassessed	serious PRR 7.2	no trial data cached
Cardiovascular disorder	11	4.5 2.5–8.1ROR 4.5 · χ² 26 / p 1e-7	3.9 EB05 2.3 · IC025 +0.9 3/3 methods agree	Labeled (related wording) related wording	serious PRR 3.3	no trial data cached
Exposure during pregnancy	23	3.9 2.6–5.8ROR 3.9 · χ² 46 / p 6e-12	3.6 EB05 2.5 · IC025 +1.2 3/3 methods agree	Reporting / coding artifact	serious PRR 3.7	no trial data cached
Foetal exposure during pregnancy	27	3.5 2.4–5.0ROR 3.5 · χ² 45 / p 9e-12	3.3 EB05 2.4 · IC025 +1.1 3/3 methods agree	Reporting / coding artifact	serious PRR 2.5 · ♀ 26% (drug 96%)	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
Ascites	223	79.7 70.4–90.3ROR 89.6 · χ² 17,149 / p <1e-300	78.6 EB05 70.3 · IC025 +5.9 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 55.4 · 93% clinician	no trial data cached
Abortion spontaneous	123	32.0 27.0–38.0ROR 34.0 · χ² 3,659 / p <1e-300	31.8 EB05 27.3 · IC025 +4.5 3/3 methods agree	Labeled (related wording) related wording	serious PRR 22.2	no trial data cached
Abdominal distension (bloating)	116	11.7 9.8–13.9ROR 12.3 · χ² 1,124 / p 1e-246	11.5 EB05 9.8 · IC025 +3.2 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 12.8	no trial data cached
Inappropriate schedule of drug administration	80	11.6 9.3–14.4ROR 12.0 · χ² 765 / p 1e-168	11.4 EB05 9.4 · IC025 +3.1 3/3 methods agree	Reporting / coding artifact	serious PRR 1.0 · 99% clinician	no trial data cached
Pleural effusion	76	13.0 10.5–16.3ROR 13.5 · χ² 834 / p 1e-183	12.9 EB05 10.6 · IC025 +3.2 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 9.3 · 96% clinician	no trial data cached
Drug exposure during pregnancy	58	17.6 13.6–22.7ROR 18.1 · χ² 890 / p 7e-196	17.4 EB05 14.0 · IC025 +3.5 3/3 methods agree	Reporting / coding artifact	serious PRR 13.5	no trial data cached
Maternal exposure during pregnancy	50	5.9 4.5–7.8ROR 6.0 · χ² 200 / p 9e-46	5.6 EB05 4.4 · IC025 +2.0 3/3 methods agree	Reporting / coding artifact	serious PRR 4.6	no trial data cached
Pregnancy	34	17.6 12.6–24.5ROR 17.9 · χ² 515 / p 3e-114	17.3 EB05 12.9 · IC025 +3.3 3/3 methods agree	Likely indication confounding term in indications; also in warnings	serious PRR 17.2	no trial data cached
Abdominal pain lower	29	11.9 8.3–17.2ROR 12.1 · χ² 280 / p 4e-63	11.4 EB05 8.0 · IC025 +2.7 3/3 methods agree	Labeled (related wording) related wording	serious PRR 12.4 · 96% clinician	no trial data cached
Foetal exposure during pregnancy	27	3.5 2.4–5.0ROR 3.5 · χ² 45 / p 9e-12	3.3 EB05 2.4 · IC025 +1.1 3/3 methods agree	Reporting / coding artifact	serious PRR 2.5 · ♀ 26% (drug 96%)	no trial data cached
Caesarean section	27	24.0 16.5–34.9ROR 24.3 · χ² 572 / p 1e-126	23.6 EB05 17.0 · IC025 +3.4 3/3 methods agree	Not in label — unassessed	serious PRR 17.0	no trial data cached
Ovarian cyst	25	26.0 17.6–38.4ROR 26.3 · χ² 575 / p 2e-127	25.5 EB05 18.1 · IC025 +3.5 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 20.9	no trial data cached
Premature baby	24	8.3 5.6–12.4ROR 8.4 · χ² 147 / p 4e-34	7.4 EB05 5.2 · IC025 +2.2 3/3 methods agree	Not in label — unassessed	serious PRR 5.8 · ♀ 55% (drug 96%)	no trial data cached
Exposure during pregnancy	23	3.9 2.6–5.8ROR 3.9 · χ² 46 / p 6e-12	3.6 EB05 2.5 · IC025 +1.2 3/3 methods agree	Reporting / coding artifact	serious PRR 3.7	no trial data cached
Vaginal haemorrhage	23	5.6 3.8–8.5ROR 5.7 · χ² 83 / p 3e-20	5.1 EB05 3.6 · IC025 +1.7 3/3 methods agree	Not in label — unassessed	serious PRR 7.2	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.

Caesarean section — n=27, PRR 24.0
Premature baby — n=24, PRR 8.3
Vaginal haemorrhage — n=23, PRR 5.6

✓ A hand-written Bradford Hill causality assessment exists for this drug: Erythropoiesis-stimulating agents (darbepoetin alfa) ↔ Mortality / cardiovascular risk.

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 Follitropin Alfa?

In FDA FAERS, the most frequently co-reported reaction terms for Follitropin Alfa are ascites, abortion spontaneous, abdominal distension, pleural effusion, pregnancy, abdominal pain lower. 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 Follitropin Alfa have an FDA boxed warning?

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

Do FAERS signals prove that Follitropin Alfa 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 ae85b9c3-e7eb-4981-a5d9-346050e8f189, effective 20250902; matched on openfda.generic_name.exact:"FOLLITROPIN ALFA")
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, 42 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.