Levothyroxine side effects: what 300,326 FDA adverse event reports show
Drug class
Not stated in label
Label matched
Levothyroxine Sodium (Levothyroxine Sodium)
Who reports
300,326 reports · 59% serious · 19,275 with death outcome · 81% female
Used for
Hypothyroidism Levothyroxine sodium tablets are indicated in adult and pediatric patients, including neonates, as a replacement therapy in primary (thyroidal), secondary (pituitary), and tertiary (hypothalamic) congenital or acquired hypothyroidism. Pi.
What it is
L-thyroxine is the L-enantiomer of thyroxine. It has a role as an antithyroid drug, a thyroid hormone, a mouse metabolite and a human metabolite.
Boxed warning
NOT FOR TREATMENT OF OBESITY OR FOR WEIGHT LOSS Thyroid hormones, including levothyroxine sodium, either alone or with other therapeutic agents, should not be used for the treatment of obesity or for weight loss. In euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction.
Causality screen of the 40 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 (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.
- 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.
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, for the 300 most-reported drugs, adjusted for age band), and flags pairs whose reports are unusually skewed by sex or come mostly from consumers. Each row also shows the PRR against the other drugs of the same FDA class, which removes most confounding by the condition being treated, and a calibrated p-value: on validation, known non-causes average an ROR of about 2, so significance is judged against that empirical null (✓ = p < 0.05 after calibration). 1,110 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 |
|---|---|---|---|---|---|---|
| Cardiospasm | 351 | 114.5 96.2–136.1ROR 114.6 · calibrated p 5e-8 ✓ | 42.1 EB05 38.5 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious n=350 · ♀ 55% (drug 81%) | not reported in cached trials |
| Immunisation | 231 | 76.5 63.2–92.5ROR 76.5 · calibrated p 1e-6 ✓ | 35.6 EB05 31.9 · IC025 +4.8 3/3 methods agree | Not in label — unassessed | serious n=228 · ♀ 0% (drug 81%) | not reported in cached trials |
| Palmoplantar keratoderma | 346 | 61.8 53.4–71.6ROR 61.9 · calibrated p 4e-6 ✓ | 32.2 EB05 29.4 · IC025 +4.8 3/3 methods agree | Not in label — unassessed | serious n=343 · ♀ 54% (drug 81%) | not reported in cached trials |
| Blood thyroid stimulating hormone abnormal | 825 | 54.3 49.5–59.5ROR 54.4 · calibrated p 8e-6 ✓ | 30.1 EB05 28.4 · IC025 +4.8 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=239 · 78% consumer | not reported in cached trials |
| Blood thyroid stimulating hormone increased | 2,599 | 26.0 24.9–27.2ROR 26.2 · calibrated p 5e-4 ✓ | 18.9 EB05 18.3 · IC025 +4.2 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=938 | not reported in cached trials |
| Blood thyroid stimulating hormone decreased | 1,281 | 26.0 24.4–27.8ROR 26.1 · calibrated p 5e-4 ✓ | 18.9 EB05 18.0 · IC025 +4.1 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=445 · 72% consumer | not reported in cached trials |
| Thyroid function test abnormal | 1,168 | 25.8 24.1–27.6ROR 25.9 · calibrated p 6e-4 ✓ | 18.8 EB05 17.9 · IC025 +4.1 3/3 methods agree | Reporting / coding artifact | serious n=425 · 79% consumer | not reported in cached trials |
| C-reactive protein | 247 | 24.8 21.4–28.7ROR 24.8 · calibrated p 7e-4 ✓ | 18.2 EB05 16.4 · IC025 +3.9 3/3 methods agree | Lab value / disease marker | serious n=246 · 100% clinician | not reported in cached trials |
| Thyroidectomy | 446 | 23.3 20.9–26.0ROR 23.3 · calibrated p 1e-3 ✓ | 17.4 EB05 16.1 · IC025 +3.9 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=419 · 100% consumer | not reported in cached trials |
| Deep vein thrombosis postoperative | 407 | 17.4 15.6–19.4ROR 17.4 · calibrated p 0.004 ✓ | 13.9 EB05 12.8 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=407 · 100% clinician | not reported in cached trials |
| Sedation complication | 491 | 16.2 14.7–17.9ROR 16.2 · calibrated p 0.005 ✓ | 13.2 EB05 12.2 · IC025 +3.6 3/3 methods agree | Reporting / coding artifact | serious n=487 · 100% clinician | not reported in cached trials |
| Atrial tachycardia | 407 | 15.8 14.2–17.7ROR 15.9 · calibrated p 0.006 ✓ | 12.9 EB05 11.9 · IC025 +3.5 3/3 methods agree | Labeled (related wording) related wording | serious n=404 · ♀ 56% (drug 81%) | not reported in cached trials |
| Blood pressure systolic abnormal | 415 | 13.2 11.9–14.7ROR 13.3 · calibrated p 0.012 ✓ | 11.1 EB05 10.3 · IC025 +3.3 3/3 methods agree | Lab value / disease marker | serious n=403 · 100% clinician | not reported in cached trials |
| Pruritus genital | 383 | 13.0 11.7–14.5ROR 13.1 · calibrated p 0.012 ✓ | 11.0 EB05 10.1 · IC025 +3.3 3/3 methods agree | Labeled (related wording) related wording | serious n=366 · ♀ 56% (drug 81%) | not reported in cached trials |
| Polycystic ovaries | 257 | 13.0 11.3–14.8ROR 13.0 · calibrated p 0.013 ✓ | 10.9 EB05 9.8 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=245 | not reported in cached trials |
| Blood pressure diastolic abnormal | 406 | 12.4 11.2–13.8ROR 12.4 · calibrated p 0.015 ✓ | 10.6 EB05 9.7 · IC025 +3.2 3/3 methods agree | Lab value / disease marker | serious n=398 · 100% clinician | not reported in cached trials |
| Autoimmune thyroiditis | 540 | 11.1 10.1–12.2ROR 11.1 · calibrated p 0.022 ✓ | 9.6 EB05 8.9 · IC025 +3.1 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=367 | not reported in cached trials |
| Creatinine renal clearance decreased | 561 | 10.7 9.8–11.7ROR 10.7 · calibrated p 0.025 ✓ | 9.3 EB05 8.7 · IC025 +3.1 3/3 methods agree | Lab value / disease marker | serious n=550 | not reported in cached trials |
| Hypothyroidism | 4,422 | 10.7 10.3–11.0ROR 10.8 · calibrated p 0.024 ✓ | 9.3 EB05 9.1 · IC025 +3.2 3/3 methods agree | Labeled — boxed warning exact term | age-adj. PRR 9.0 · serious PRR 8.1 | not reported in cached trials |
| Schizoaffective disorder | 237 | 10.1 8.8–11.6ROR 10.1 · calibrated p 0.032 ✓ | 8.8 EB05 7.9 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious n=237 · 100% clinician | not reported in cached trials |
| Swollen joint count increased | 402 | 9.8 8.8–10.9ROR 9.8 · calibrated p 0.035 ✓ | 8.6 EB05 7.9 · IC025 +2.9 3/3 methods agree | Lab value / disease marker | serious n=402 · 100% clinician | not reported in cached trials |
| Carotid artery occlusion | 453 | 9.4 8.5–10.3ROR 9.4 · calibrated p 0.041 ✓ | 8.3 EB05 7.6 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious n=446 · ♀ 61% (drug 81%) | not reported in cached trials |
| Tension headache | 474 | 8.2 7.5–9.0ROR 8.2 · calibrated p 0.062 | 7.4 EB05 6.8 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious n=422 | not reported in cached trials |
| Thyroid disorder | 1,696 | 8.2 7.8–8.6ROR 8.2 · calibrated p 0.061 | 7.4 EB05 7.1 · IC025 +2.8 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 6.7 · 71% consumer | not reported in cached trials |
| Rheumatic fever | 473 | 8.0 7.3–8.8ROR 8.0 · calibrated p 0.066 | 7.2 EB05 6.7 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious n=473 · 100% clinician | not reported in cached trials |
| C-reactive protein abnormal | 664 | 7.7 7.1–8.3ROR 7.7 · calibrated p 0.076 | 6.9 EB05 6.5 · IC025 +2.7 3/3 methods agree | Lab value / disease marker | serious n=662 | not reported in cached trials |
| Rhinitis allergic | 460 | 7.6 6.9–8.4ROR 7.7 · calibrated p 0.077 | 6.9 EB05 6.4 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=428 | not reported in cached trials |
| Goitre | 420 | 7.5 6.8–8.3ROR 7.5 · calibrated p 0.080 | 6.8 EB05 6.3 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=312 | not reported in cached trials |
| Personality disorder | 256 | 7.1 6.3–8.1ROR 7.1 · calibrated p 0.095 | 6.4 EB05 5.8 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious n=241 · 100% clinician | not reported in cached trials |
| Thyroid neoplasm | 256 | 6.7 5.9–7.6ROR 6.7 · calibrated p 0.114 | 6.1 EB05 5.5 · IC025 +2.4 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=216 · 100% consumer | not reported in cached trials |
| Hyperthyroidism | 1,321 | 6.6 6.3–7.0ROR 6.7 · calibrated p 0.113 | 6.1 EB05 5.8 · IC025 +2.5 3/3 methods agree | Labeled — boxed warning synonym match | age-adj. PRR 4.5 · serious PRR 4.2 | not reported in cached trials |
| Sleep terror | 384 | 6.6 6.0–7.4ROR 6.7 · calibrated p 0.115 | 6.1 EB05 5.6 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious n=364 · ♀ 58% (drug 81%) | not reported in cached trials |
| Facet joint syndrome | 273 | 6.3 5.5–7.1ROR 6.3 · calibrated p 0.135 | 5.8 EB05 5.2 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious n=270 · 100% clinician | not reported in cached trials |
| Blood pressure diastolic decreased | 618 | 6.0 5.5–6.5ROR 6.0 · calibrated p 0.149 | 5.6 EB05 5.2 · IC025 +2.3 3/3 methods agree | Lab value / disease marker | serious PRR 5.8 | not reported in cached trials |
| Rheumatoid factor positive | 480 | 6.0 5.5–6.6ROR 6.0 · calibrated p 0.150 | 5.6 EB05 5.1 · IC025 +2.3 3/3 methods agree | Lab value / disease marker | serious n=477 · 100% clinician | not reported in cached trials |
| Peripheral venous disease | 329 | 5.9 5.3–6.6ROR 5.9 · calibrated p 0.155 | 5.5 EB05 5.0 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious n=312 · 100% clinician | not reported in cached trials |
| Blood calcium decreased | 927 | 5.9 5.5–6.3ROR 5.9 · calibrated p 0.154 | 5.5 EB05 5.2 · IC025 +2.4 3/3 methods agree | Lab value / disease marker | serious PRR 6.3 | not reported in cached trials |
| Coeliac disease | 770 | 5.6 5.2–6.1ROR 5.6 · calibrated p 0.176 | 5.2 EB05 4.9 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 3.0 · 77% consumer | not reported in cached trials |
| Blood pressure systolic increased | 1,481 | 5.4 5.1–5.7ROR 5.4 · calibrated p 0.193 | 5.1 EB05 4.9 · IC025 +2.3 3/3 methods agree | Lab value / disease marker | serious PRR 5.3 | not reported in cached trials |
| Thyroid mass | 283 | 5.3 4.7–6.0ROR 5.3 · calibrated p 0.203 | 5.0 EB05 4.5 · IC025 +2.1 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=216 · 100% consumer | not reported in cached trials |
Clinical concept groups
MedDRA splits one clinical problem across several terms (e.g. "neutropenia", "neutrophil count decreased", "agranulocytosis"), which dilutes term-level signals. These rows count reports with any term in a concept group (an exact union, not a sum), compared with all other drugs. Groups are hand-built and listed in the methods.
| Concept | Reports | PRR 95% CI | Reading |
|---|---|---|---|
| Fall / fracture | 12,336 | 2.32.3–2.3 | signal |
| Hyponatraemia | 2,560 | 2.32.2–2.3 | signal |
| Arrhythmia / qt | 6,020 | 2.22.2–2.3 | signal |
| Depression | 7,728 | 1.91.9–2.0 | raised |
| Anaemia | 8,029 | 1.91.9–1.9 | raised |
| Tendon disorder | 968 | 1.81.7–1.9 | raised |
| Hypoglycaemia | 2,410 | 1.81.7–1.8 | raised |
| Hyperglycaemia / diabetes | 8,637 | 1.81.7–1.8 | raised |
| Serious infection | 19,208 | 1.81.7–1.8 | raised |
| Gi bleeding | 4,439 | 1.71.7–1.8 | raised |
| Venous thromboembolism | 5,218 | 1.71.7–1.7 | raised |
| Heart failure | 4,114 | 1.61.6–1.7 | raised |
| Pancreatitis | 1,762 | 1.51.5–1.6 | raised |
| Opportunistic infection | 2,966 | 1.51.5–1.6 | raised |
| Interstitial lung disease | 2,051 | 1.51.4–1.6 | raised |
| Kidney injury | 9,497 | 1.51.4–1.5 | raised |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Levothyroxine as a study intervention. The right-hand column of the signal table shows whether each FAERS term was also recorded in these trials, with a real denominator (0 of 40 signal terms matched).
- NCT00388297 — Thyroid Therapy for Mild Thyroid Deficiency in Pregnancy (N=1203, PHASE3; 17 AE terms posted; arms: Levothyroxine for Subclinical Hypothyroi; Placebo for Levothyroxine - Subclinincal; Levothyroxine for Hypothyroxinemia - Hyp; Placebo for Levothyroxine)
- NCT04124705 — A Study of Armour® Thyroid Compared to Synthetic T4 (Levothyroxine) in Previously Hypothyroid Participants (N=284, PHASE2; 16 AE terms posted; arms: Armour® Thyroid; Levothyroxine)
Caveats: trial populations, doses and follow-up differ from the reporting population; AE terms are sponsor-coded and matched here by wording; absence from a trial list means the term was not reported above the sponsor's frequency threshold, not that it cannot occur.
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 |
|---|---|---|---|---|---|---|
| Fatigue (tiredness) | 26,580 | 2.3 2.3–2.4ROR 2.5 · calibrated p 0.827 | 2.3 EB05 2.3 · IC025 +1.2 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 2.1 · serious PRR 2.6 | NCT00388297: 5/259 (1.9%) on Levothyroxine; 4/336 (1.2%) control |
| Nausea | 22,600 | 1.9 1.9–2.0ROR 2.0 · calibrated p 0.957 | 1.9 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | age-adj. PRR 1.9 · serious PRR 2.3 | NCT00388297: 15/259 (5.8%) on Levothyroxine; 8/336 (2.4%) control |
| Drug ineffective (drug did not work) | 21,089 | 1.1 1.1–1.1ROR 1.1 · calibrated p 0.360 | 1.1 EB05 1.1 · IC025 +0.1 | Reporting / coding artifact | age-adj. PRR 1.3 · serious PRR 1.4 | not reported in cached trials |
| Headache | 19,405 | 2.1 2.1–2.1ROR 2.2 · calibrated p 0.957 | 2.1 EB05 2.1 · IC025 +1.0 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 2.2 · serious PRR 2.5 | NCT00388297: 4/259 (1.5%) on Levothyroxine; 8/336 (2.4%) control |
| Diarrhoea (diarrhea) | 18,753 | 2.0 2.0–2.0ROR 2.0 · calibrated p 0.970 | 2.0 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | age-adj. PRR 1.8 · serious PRR 2.1 | not reported in cached trials |
| Dyspnoea (shortness of breath) | 16,723 | 2.0 2.0–2.0ROR 2.1 · calibrated p 0.983 | 2.0 EB05 2.0 · IC025 +1.0 | Labeled adverse reaction exact term | age-adj. PRR 1.9 · serious PRR 2.1 | not reported in cached trials |
| Pain | 16,373 | 1.8 1.8–1.8ROR 1.9 · calibrated p 0.860 | 1.8 EB05 1.8 · IC025 +0.8 | Labeled adverse reaction exact term | age-adj. PRR 2.2 · serious PRR 2.1 | NCT00388297: 1/339 (0.3%) on Levothyroxine (serious AE) |
| Dizziness | 15,847 | 2.2 2.1–2.2ROR 2.2 · calibrated p 0.934 | 2.1 EB05 2.1 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | age-adj. PRR 2.0 · serious PRR 2.3 | not reported in cached trials |
| Asthenia (weakness) | 13,501 | 2.5 2.4–2.5ROR 2.5 · calibrated p 0.801 | 2.4 EB05 2.4 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | age-adj. PRR 2.1 · serious PRR 2.4 | not reported in cached trials |
| Off label use (used outside approved label) | 13,488 | 1.0 1.0–1.1ROR 1.0 · calibrated p 0.336 | 1.0 EB05 1.0 · IC025 +0.0 | Reporting / coding artifact | age-adj. PRR 1.1 · serious PRR 1.3 | not reported in cached trials |
| Arthralgia (joint pain) | 13,422 | 2.2 2.2–2.3ROR 2.3 · calibrated p 0.918 | 2.2 EB05 2.1 · IC025 +1.1 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 2.1 · serious PRR 2.7 | not reported in cached trials |
| Malaise (feeling unwell) | 12,427 | 1.9 1.9–2.0ROR 2.0 · calibrated p 0.923 | 1.9 EB05 1.9 · IC025 +0.9 | Not in label — unassessed | age-adj. PRR 1.8 · serious PRR 2.2 | not reported in cached trials |
| Vomiting | 11,938 | 1.7 1.7–1.8ROR 1.8 · calibrated p 0.803 | 1.7 EB05 1.7 · IC025 +0.7 | Labeled adverse reaction exact term | age-adj. PRR 1.8 · serious PRR 1.9 | NCT00388297: 15/259 (5.8%) on Levothyroxine; 8/336 (2.4%) control |
| Fall | 11,772 | 2.4 2.4–2.5ROR 2.5 · calibrated p 0.820 | 2.4 EB05 2.3 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | age-adj. PRR 2.0 · serious PRR 2.5 | not reported in cached trials |
| Weight decreased (weight loss) | 10,032 | 2.5 2.4–2.5ROR 2.5 · calibrated p 0.807 | 2.4 EB05 2.4 · IC025 +1.2 3/3 methods agree | Labeled — boxed warning synonym match | age-adj. PRR 2.3 · serious PRR 2.6 | not reported in cached trials |
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.
- Cardiospasm — n=351, PRR 114.5
- Immunisation — n=231, PRR 76.5
- Palmoplantar keratoderma — n=346, PRR 61.8
- Deep vein thrombosis postoperative — n=407, PRR 17.4
- Polycystic ovaries — n=257, PRR 13.0
- Schizoaffective disorder — n=237, PRR 10.1
- Carotid artery occlusion — n=453, PRR 9.4
- Tension headache — n=474, PRR 8.2
- Rheumatic fever — n=473, PRR 8.0
- Rhinitis allergic — n=460, PRR 7.6
✓ A hand-written Bradford Hill causality assessment exists for this drug: Methotrexate Sodium ↔ Rheumatoid Arthritis.
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 Levothyroxine?
In FDA FAERS, the most frequently co-reported reaction terms for Levothyroxine are fatigue, nausea, headache, diarrhoea, dyspnoea, pain. 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 Levothyroxine have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: NOT FOR TREATMENT OF OBESITY OR FOR WEIGHT LOSS Thyroid hormones, including levothyroxine sodium, either alone or with other therapeutic agents, should not be used for the treatment of obesity or for weight loss. In euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction.
Do FAERS signals prove that Levothyroxine 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 008de8fd-150f-4022-8ccb-c8bfa94875c7, effective 20260324; matched on
openfda.generic_name.exact:"LEVOTHYROXINE SODIUM") - PubChem CID 5819 description (ChEBI)
- 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, 1,150 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 - ClinicalTrials.gov API v2 (query
LEVOTHYROXINE, results-bearing studies sorted by enrollment)
Page generated 2026-10-14. 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.