Tryptophan side effects: what 352 FDA adverse event reports show

Tryptophan · 14 reaction terms · 142 drug–reaction co-reports · data 2026-09-14

Drug class

Not stated in label

Who reports

352 reports · 83% serious · 48 with death outcome · 72% female

openFDA FAERS counts, all years, deduplication not applied

Used for

• For the temporary relief of symptoms including: • sleep issues • bloating • poor digestion • flatulence • occasional constipation These statements are based upon homeopathic principles. They have not been reviewed by the Food and Drug Administration.

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 12 strongest signals

Reporting / coding artifact 4Lab value / disease marker 1No label text to screen 7

What the badges mean

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.
Lab value / disease marker A laboratory result, investigation or disease-activity marker (antibody positive, CRP abnormal, swollen joint count) not described in the label. These usually mirror the monitored disease or testing protocol rather than a drug effect; not screened further.
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.
No label text to screen No validated FDA label was retrievable for this product, so the screen could not run. Disproportionality only.

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. 2 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
Serotonin syndrome	28	87.3 61.2–124.6ROR 94.8 · χ² 2,302 / p <1e-300	82.4 EB05 59.9 · IC025 +4.5 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 60.8 · ♀ 46% (drug 72%)	no trial data cached
Product use complaint	18	69.3 44.1–108.6ROR 72.9 · χ² 1,143 / p 7e-251	64.6 EB05 43.3 · IC025 +3.8 3/3 methods agree	Reporting / coding artifact	serious n=17	no trial data cached
Taste disorder	18	53.6 34.1–84.0ROR 56.4 · χ² 877 / p 6e-193	50.8 EB05 34.0 · IC025 +3.7 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 74.3	no trial data cached
Blood calcium decreased	8	42.3 21.3–83.9ROR 43.2 · χ² 282 / p 1e-63	38.6 EB05 20.9 · IC025 +2.4 3/3 methods agree	Lab value / disease marker	serious PRR 36.5	no trial data cached
Rebound effect	8	42.0 21.2–83.4ROR 43.0 · χ² 281 / p 3e-63	38.4 EB05 20.8 · IC025 +2.4 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 46.7	no trial data cached
Inappropriate antidiuretic hormone secretion	7	41.0 19.7–85.4ROR 41.8 · χ² 235 / p 3e-53	37.0 EB05 19.1 · IC025 +2.2 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 28.6	no trial data cached
Personality change	5	31.9 13.3–76.1ROR 32.3 · χ² 120 / p 3e-28	27.4 EB05 10.6 · IC025 +1.5 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 29.6	no trial data cached
Akathisia (inner restlessness)	6	26.2 11.8–57.9ROR 26.6 · χ² 121 / p 2e-28	23.2 EB05 9.7 · IC025 +1.7 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 25.8	no trial data cached
Therapy partial responder	6	23.7 10.7–52.5ROR 24.1 · χ² 109 / p 8e-26	20.8 EB05 8.1 · IC025 +1.7 3/3 methods agree	Reporting / coding artifact	serious PRR 19.9	no trial data cached
Contraindicated product administered	12	23.7 13.6–41.3ROR 24.5 · χ² 239 / p 3e-54	22.8 EB05 13.6 · IC025 +2.7 3/3 methods agree	Reporting / coding artifact	serious PRR 18.7	no trial data cached
Sedation	8	18.3 9.2–36.3ROR 18.7 · χ² 114 / p 6e-27	16.3 EB05 7.3 · IC025 +2.0 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 17.4	no trial data cached
Drug abuse	10	7.1 3.9–13.1ROR 7.3 · χ² 47 / p 4e-12	5.6 EB05 3.2 · IC025 +1.4 3/3 methods agree	Reporting / coding artifact	serious PRR 5.0	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
Serotonin syndrome	28	87.3 61.2–124.6ROR 94.8 · χ² 2,302 / p <1e-300	82.4 EB05 59.9 · IC025 +4.5 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 60.8 · ♀ 46% (drug 72%)	no trial data cached
Taste disorder	18	53.6 34.1–84.0ROR 56.4 · χ² 877 / p 6e-193	50.8 EB05 34.0 · IC025 +3.7 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 74.3	no trial data cached
Product use complaint	18	69.3 44.1–108.6ROR 72.9 · χ² 1,143 / p 7e-251	64.6 EB05 43.3 · IC025 +3.8 3/3 methods agree	Reporting / coding artifact	serious n=17	no trial data cached
Contraindicated product administered	12	23.7 13.6–41.3ROR 24.5 · χ² 239 / p 3e-54	22.8 EB05 13.6 · IC025 +2.7 3/3 methods agree	Reporting / coding artifact	serious PRR 18.7	no trial data cached
Drug abuse	10	7.1 3.9–13.1ROR 7.3 · χ² 47 / p 4e-12	5.6 EB05 3.2 · IC025 +1.4 3/3 methods agree	Reporting / coding artifact	serious PRR 5.0	no trial data cached
Sedation	8	18.3 9.2–36.3ROR 18.7 · χ² 114 / p 6e-27	16.3 EB05 7.3 · IC025 +2.0 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 17.4	no trial data cached
Rebound effect	8	42.0 21.2–83.4ROR 43.0 · χ² 281 / p 3e-63	38.4 EB05 20.8 · IC025 +2.4 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 46.7	no trial data cached
Blood calcium decreased	8	42.3 21.3–83.9ROR 43.2 · χ² 282 / p 1e-63	38.6 EB05 20.9 · IC025 +2.4 3/3 methods agree	Lab value / disease marker	serious PRR 36.5	no trial data cached
Inappropriate antidiuretic hormone secretion	7	41.0 19.7–85.4ROR 41.8 · χ² 235 / p 3e-53	37.0 EB05 19.1 · IC025 +2.2 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 28.6	no trial data cached
Therapy partial responder	6	23.7 10.7–52.5ROR 24.1 · χ² 109 / p 8e-26	20.8 EB05 8.1 · IC025 +1.7 3/3 methods agree	Reporting / coding artifact	serious PRR 19.9	no trial data cached
Akathisia (inner restlessness)	6	26.2 11.8–57.9ROR 26.6 · χ² 121 / p 2e-28	23.2 EB05 9.7 · IC025 +1.7 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 25.8	no trial data cached
Personality change	5	31.9 13.3–76.1ROR 32.3 · χ² 120 / p 3e-28	27.4 EB05 10.6 · IC025 +1.5 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 29.6	no trial data cached
Neuroleptic malignant syndrome	4	20.0 7.6–53.1ROR 20.3 · χ² 55 / p 7e-14	14.0 EB05 3.8 · IC025 +0.9 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 13.9	no trial data cached
Inflammatory bowel disease	4	24.2 9.1–64.2ROR 24.5 · χ² 67 / p 1e-16	18.1 EB05 4.7 · IC025 +1.0 3/3 methods agree	No label text to screen label has no adverse-reaction text	serious PRR 17.1	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 Tryptophan?

In FDA FAERS, the most frequently co-reported reaction terms for Tryptophan are serotonin syndrome, taste disorder, sedation, rebound effect, blood calcium decreased, inappropriate antidiuretic hormone secretion. 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 Tryptophan have an FDA boxed warning?

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

Do FAERS signals prove that Tryptophan 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 70685fd1-9336-44d3-b270-3b3afd7635ca, effective 20240923; matched on openfda.generic_name.exact:"TRYPTOPHAN")
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, 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.