Ceramides are the fat molecules that seal skin's outer layer, and messengers inside the body whose build-up tracks with poorer blood-sugar handling and heart disease. Creams containing them help skin hold water and lengthen calm periods between eczema flare-ups. Oral plant extracts raise skin moisture in small, company-run trials. Whether they change the body's ceramide stores is unmeasured. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Transepidermal water loss | 5–12 g/m²/h on volar forearm | Direct measure of barrier leakiness; the primary endpoint in most trials |
| Stratum corneum hydration (corneometry) | >45 arbitrary units on volar forearm | Tracks water content of the outer layer, the outcome oral extracts move |
| Plasma ceramide risk score (CERT1 or CERT2) | 0–2 of 12 (low-risk band) | Grades cardiovascular risk from ceramide species; addresses this intervention's open systemic question |
| Cer(d18:1/24:0) to Cer(d18:1/16:0) ratio | No established target exists; track change from the individual's own baseline | A higher ratio was associated with lower coronary and mortality risk in community cohorts |
| Fasting insulin | 2–5 µIU/mL | Ceramide accumulation blocks insulin signalling, so insulin is the earliest functional readout |
| HOMA-IR | <1.5 | Combines fasting glucose and insulin into a single insulin-resistance index |
| Haemoglobin A1c | 4.8–5.3% | Three-month average blood sugar; the downstream consequence if ceramide-driven insulin resistance progresses |
| High-sensitivity C-reactive protein | <1.0 mg/L | General inflammation marker that correlates with ceramide risk scores |
| Wheat-specific immunoglobulin E | <0.35 kU/L (undetectable) | Identifies the one allergy that contraindicates wheat-derived oral extracts |
Cadence: Skin measurements repeated at 4 weeks and 12 weeks to judge the trial, then every 6–12 months; blood panel repeated at 6 months and annually