Summary
| Direction in Long COVID | ↕ Inconsistent — reported as both higher and lower across studies, with no consistent direction |
|---|---|
| Category | Inflammatory |
| Also described as | Acute phase reactant |
| Compared against | HC (healthy controls) |
| Associated symptoms | Iron metabolism dysregulation |
| Test type | Blood test (serum / plasma / whole blood) |
| LOINC code | 2276-4 |
| Source | Thomas et al. 2024 — doi:10.1007/s40291-024-00731-z |
| Condition atlas | Long COVID Biomarker Atlas |
Other conditions where Ferritin is reported
- Ferritin in NAFLD / MASH (Metabolic-Associated Steatohepatitis) — ↑ elevated vs NAFLD vs normal/no iron overload
- Ferritin index in PACVS — ↓ reduced vs HC
See the cross-condition hub: Ferritin across conditions.
Trials, interventions and tests
In clinical-trial registrations this marker maps to the outcome term Change in Ferritin Levels (6 registered trials use a matching outcome measure).
Clinical trials using Ferritin as an outcome
- NCT05710770: Immunoadsorption in Patients With Chronic Fatigue Syndrome Including Patients With Post-COVID-19 CFS (Completed)
Outcome measure: Changes in biomarkers of inflammation - NCT07046208: Effects os Physiotherapeutic Rehabilitation on Function Autonomic and Inflammatory in Patients With Long Covid (Not Yet Recruiting)
Outcome measure: Inflammation - NCT06597682: Evaluating Immunomodulatory Interventions in Post-Acute Sequelae of SARS-CoV-2 InfEction (Not Yet Recruiting)
Outcome measure: Change in Ferritin Levels - NCT05823896: ImPROving Quality of LIFe in the Long COVID Patient (Completed)
Outcome measure: Change from baseline in plasma biomarkers over time - NCT04482595: BIO 300 Oral Suspension in Previously Hospitalized Long COVID Patients (Unknown)
Outcome measure: Change in Clinical Laboratory Values - NCT05531019: COVID-19 Sequelae: Treatment and Monitoring. A Dietary Supplement Based on Sea Urchin Eggs With Echinochroma A (Completed)
Outcome measure: Change of Ferritin over time-points (baseline, 4 weeks, 8 weeks, 12 weeks) via blood sample.
Interventions studied alongside this marker
Hypothesis-generating links from trial outcome usage and literature co-occurrence. Not treatment recommendations.
- Immunoadsorption — 1 trial, 6 PubMed co-citations
e.g. Effects of Immunoadsorption on Markers of Iron Metabolism: A Case Series. - Coenzyme Q10 — 1 trial, 6 PubMed co-citations
e.g. Antioxidant Effects of CoQ10 in Transfusion-Dependent β-Thalassemia Major Patients: Implications for… - Paxlovid — 1 trial, 1 PubMed co-citations
e.g. Paxlovid administration in elderly patient with COVID-19 caused by Omicron BA.2.0: A case report.
Commercial test availability
Ferritin — commercial laboratory test.
Links are for reference only; availability, specimen requirements and coverage vary by location.
Related Inflammatory markers in Long COVID
- Interleukin-10 (IL-10) ↕
- Serum Amyloid A (SAA) ↑
- Interleukin-8 (IL-8) ↑
- Transforming Growth Factor-β (TGF-β) ↑
- Pro-inflammatory cytokines (composite) ↓
- Cystatin D (CST5) ↑
- CCL4 (MIP-1β) ↑
- Flt-1 / sVEGFR-1 ↑
Full list: Long COVID Biomarker Atlas.
Frequently asked questions
Is Ferritin high or low in Long COVID?
Mixed. Some studies report higher and others lower Ferritin in Long COVID compared with healthy controls, so no single direction is established. Source: Thomas et al. 2024.
What symptoms is Ferritin associated with in Long COVID?
The cited literature associates this marker with Iron metabolism dysregulation. These are population-level associations and do not mean the marker causes the symptoms.
Which test measures Ferritin?
It is measured as a blood test (serum / plasma / whole blood). The standard laboratory code is LOINC 2276-4. Commercial laboratories such as Quest Diagnostics, LabCorp, Ulta Lab Tests list an orderable assay.
Is one abnormal Ferritin result diagnostic of Long COVID?
No. No single biomarker is diagnostic of Long COVID. Ferritin findings come from group comparisons, overlap considerably between patients and controls, and vary with study design, timing and comparison group. A result should be interpreted by a clinician alongside symptoms, history and other tests.
Is Ferritin specific to Long COVID?
No. The same marker is also reported in NAFLD / MASH (Metabolic-Associated Steatohepatitis), PACVS in this atlas, so it reflects shared biology (for example inflammation or vascular stress) rather than a condition-specific signature.
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Last reviewed: 2026-06-29 · Page generated from long-covid.json · Browse: Long COVID atlas · Biomarker Index · All marker pages
Disclaimer: This page is an educational synthesis of published, peer-reviewed research and is not medical advice. Biomarker findings vary across studies with case definitions, comparison groups, timing and assay methods. Direction of change reflects the predominant finding in the cited source and does not establish a diagnostic threshold. Discuss any test result with a qualified clinician.