Lenacapavir side effects: what 462 FDA adverse event reports show
Drug class
Not stated in label
Label matched
Lenacapavir Sodium (Yeztugo)
Who reports
462 reports · 19% serious · 0 with death outcome · 8% female
Used for
YEZTUGO is indicated for pre‑exposure prophylaxis (PrEP) to reduce the risk of sexually acquired HIV-1 in adults and adolescents weighing at least 35 kg who are at risk for HIV-1 acquisition. Individuals must have a negative HIV-1 test prior to initiating YEZTUGO .
What it is
YEZTUGO tablets and YEZTUGO injection contain lenacapavir sodium, a capsid inhibitor.
Boxed warning
RISK OF DRUG RESISTANCE WITH USE OF YEZTUGO FOR HIV-1 PRE-EXPOSURE PROPHYLAXIS (PrEP) IN UNDIAGNOSED HIV-1 INFECTION Individuals must be tested for HIV-1 infection prior to initiating YEZTUGO, and with each subsequent injection of YEZTUGO, using a test approved or cleared by the FDA for the diagnosis of acute or primary HIV-1 infection.
Causality screen of the 11 strongest signals
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.
- 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. 3 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Injection site nodule | 111 | 463.3 393.5–545.5ROR 609.5 · χ² 50,253 / p <1e-300 | 424.9 EB05 362.6 · IC025 +6.9 3/3 methods agree | Labeled adverse reaction exact term | serious n=16 | no trial data cached |
| Injection site mass | 36 | 44.4 32.4–60.7ROR 48.0 · χ² 1,484 / p <1e-300 | 43.4 EB05 32.7 · IC025 +4.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 100.1 | no trial data cached |
| Injection site discomfort | 9 | 39.6 20.7–75.6ROR 40.4 · χ² 301 / p 1e-67 | 36.7 EB05 20.6 · IC025 +2.6 3/3 methods agree | Labeled (related wording) related wording | serious n=1 | no trial data cached |
| Injection site pain (pain where injected) | 137 | 20.5 17.8–23.6ROR 28.7 · χ² 2,557 / p <1e-300 | 20.4 EB05 17.7 · IC025 +4.0 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 70.5 | no trial data cached |
| Product administered at inappropriate site | 7 | 17.5 8.4–36.5ROR 17.8 · χ² 93 / p 3e-22 | 14.9 EB05 6.1 · IC025 +1.8 3/3 methods agree | Reporting / coding artifact | serious n=1 | no trial data cached |
| Injection site erythema (redness where injected) | 40 | 14.7 10.9–19.8ROR 16.0 · χ² 500 / p 4e-111 | 14.5 EB05 11.0 · IC025 +3.1 3/3 methods agree | Labeled (related wording) related wording | serious PRR 68.8 | no trial data cached |
| Injection site swelling | 24 | 14.4 9.7–21.2ROR 15.1 · χ² 287 / p 1e-64 | 13.9 EB05 9.5 · IC025 +2.8 3/3 methods agree | Labeled (related wording) related wording | serious PRR 59.2 | no trial data cached |
| Injection site warmth | 5 | 11.0 4.6–26.4ROR 11.1 · χ² 36 / p 9e-10 | 7.1 EB05 2.9 · IC025 +1.0 3/3 methods agree | Labeled (related wording) related wording | serious n=2 | no trial data cached |
| Injection site bruising | 15 | 8.6 5.2–14.2ROR 8.9 · χ² 94 / p 1e-22 | 7.3 EB05 4.5 · IC025 +1.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 53.3 | no trial data cached |
| Injection site reaction | 12 | 7.9 4.5–13.9ROR 8.1 · χ² 66 / p 2e-16 | 6.4 EB05 3.8 · IC025 +1.7 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 52.3 | no trial data cached |
| Injection site haemorrhage | 9 | 5.1 2.7–9.8ROR 5.2 · χ² 26 / p 2e-7 | 4.2 EB05 2.4 · IC025 +0.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 13.0 | no trial data cached |
Trial evidence (ClinicalTrials.gov)
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 |
|---|---|---|---|---|---|---|
| Injection site pain (pain where injected) | 137 | 20.5 17.8–23.6ROR 28.7 · χ² 2,557 / p <1e-300 | 20.4 EB05 17.7 · IC025 +4.0 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 70.5 | no trial data cached |
| Injection site nodule | 111 | 463.3 393.5–545.5ROR 609.5 · χ² 50,253 / p <1e-300 | 424.9 EB05 362.6 · IC025 +6.9 3/3 methods agree | Labeled adverse reaction exact term | serious n=16 | no trial data cached |
| Injection site erythema (redness where injected) | 40 | 14.7 10.9–19.8ROR 16.0 · χ² 500 / p 4e-111 | 14.5 EB05 11.0 · IC025 +3.1 3/3 methods agree | Labeled (related wording) related wording | serious PRR 68.8 | no trial data cached |
| Injection site mass | 36 | 44.4 32.4–60.7ROR 48.0 · χ² 1,484 / p <1e-300 | 43.4 EB05 32.7 · IC025 +4.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 100.1 | no trial data cached |
| Injection site swelling | 24 | 14.4 9.7–21.2ROR 15.1 · χ² 287 / p 1e-64 | 13.9 EB05 9.5 · IC025 +2.8 3/3 methods agree | Labeled (related wording) related wording | serious PRR 59.2 | no trial data cached |
| Injection site bruising | 15 | 8.6 5.2–14.2ROR 8.9 · χ² 94 / p 1e-22 | 7.3 EB05 4.5 · IC025 +1.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 53.3 | no trial data cached |
| Injection site reaction | 12 | 7.9 4.5–13.9ROR 8.1 · χ² 66 / p 2e-16 | 6.4 EB05 3.8 · IC025 +1.7 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 52.3 | no trial data cached |
| Injection site haemorrhage | 9 | 5.1 2.7–9.8ROR 5.2 · χ² 26 / p 2e-7 | 4.2 EB05 2.4 · IC025 +0.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 13.0 | no trial data cached |
| Injection site discomfort | 9 | 39.6 20.7–75.6ROR 40.4 · χ² 301 / p 1e-67 | 36.7 EB05 20.6 · IC025 +2.6 3/3 methods agree | Labeled (related wording) related wording | serious n=1 | no trial data cached |
| Product administered at inappropriate site | 7 | 17.5 8.4–36.5ROR 17.8 · χ² 93 / p 3e-22 | 14.9 EB05 6.1 · IC025 +1.8 3/3 methods agree | Reporting / coding artifact | serious n=1 | no trial data cached |
| Injection site warmth | 5 | 11.0 4.6–26.4ROR 11.1 · χ² 36 / p 9e-10 | 7.1 EB05 2.9 · IC025 +1.0 3/3 methods agree | Labeled (related wording) related wording | serious n=2 | no trial data cached |
| Injection site induration | 4 | 14.0 5.3–37.2ROR 14.1 · χ² 36 / p 9e-10 | 8.5 EB05 2.8 · IC025 +0.8 3/3 methods agree | Labeled (related wording) related wording | serious n=1 | no trial data cached |
| Injection site irritation | 4 | 14.4 5.4–38.1ROR 14.5 · χ² 37 / p 5e-10 | 8.8 EB05 2.9 · IC025 +0.8 3/3 methods agree | Labeled (related wording) related wording | serious n=1 | no trial data cached |
| Injection site discolouration | 3 | 11.0 3.6–33.9ROR 11.0 · χ² 18 / p 1e-5 | 5.6 EB05 1.9 · IC025 +0.1 | Labeled (related wording) related wording | – | no trial data cached |
Unlabeled candidate signals
Every screened signal with n ≥ 20 was either labeled, an indication term, or an artifact pattern — no unlabeled candidate stood out in the top signals.
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 Lenacapavir?
In FDA FAERS, the most frequently co-reported reaction terms for Lenacapavir are injection site pain, injection site nodule, injection site erythema, injection site mass, injection site swelling, injection site bruising. 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 Lenacapavir have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: RISK OF DRUG RESISTANCE WITH USE OF YEZTUGO FOR HIV-1 PRE-EXPOSURE PROPHYLAXIS (PrEP) IN UNDIAGNOSED HIV-1 INFECTION Individuals must be tested for HIV-1 infection prior to initiating YEZTUGO, and with each subsequent injection of YEZTUGO, using a test approved or cleared by the FDA for the diagnosis of acute or primary HIV-1 infection.
Do FAERS signals prove that Lenacapavir 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 1c241af1-ce62-4b0a-9eb7-f6b626174f01, effective 20260811; matched on
openfda.generic_name.exact:"LENACAPAVIR SODIUM") - 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, fieldpatient.drug.openfda.generic_name.exact, 14 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.