Summary
| Direction in ME/CFS | ↑ Elevated — higher than in the comparison group |
|---|---|
| Category | Metabolic |
| Also described as | Long-chain acylcarnitine |
| Compared against | HC (healthy controls) |
| Associated symptoms | Fatty acid metabolism block |
| Test type | Blood test (serum / plasma / whole blood) |
| Source | Jinushi et al. 2023 — doi:10.1186/s12967-023-04347-4 |
| Condition atlas | ME/CFS Biomarker Atlas |
Trials, interventions and tests
Also sold as a nutrient or supplement
L-Carnitine / Acylcarnitines (supplement). Includes ALCAR and acylcarnitine complexes. This tag means the analyte is also available orally; it is not a product endorsement and a low or high level does not by itself justify supplementation.
Related Metabolic markers in ME/CFS
- C16 Acylcarnitine (palmitoylcarnitine) ↑
- Free carnitine ↕
- Acylcarnitines (composite) ↑
- Lactate (blood) ↑
- Serine ↓
- Sarcosine ↓
- Kynurenine ↑
- Ceramides (plasma) ↓
Full list: ME/CFS Biomarker Atlas.
Frequently asked questions
Is C18 Acylcarnitine (stearoylcarnitine) high or low in ME/CFS?
Elevated. Studies summarised in the OSMF atlas report higher C18 Acylcarnitine (stearoylcarnitine) in ME/CFS than in healthy controls. Source: Jinushi et al. 2023.
What symptoms is C18 Acylcarnitine (stearoylcarnitine) associated with in ME/CFS?
The cited literature associates this marker with Fatty acid metabolism block. These are population-level associations and do not mean the marker causes the symptoms.
Which test measures C18 Acylcarnitine (stearoylcarnitine)?
It is measured as a blood test (serum / plasma / whole blood). Many of the cited studies used research-grade assays, so clinical availability may vary.
Is one abnormal C18 Acylcarnitine (stearoylcarnitine) result diagnostic of ME/CFS?
No. No single biomarker is diagnostic of ME/CFS. C18 Acylcarnitine (stearoylcarnitine) 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.
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Last reviewed: 2026-06-29 · Page generated from me-cfs.json · Browse: ME/CFS 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.