Oregano oil is a concentrated extract, not a spice. Human evidence is limited to short courses against documented gut infections, not a daily longevity tonic. Isolated main-compound capsules and water distillates are not the same as retail capsules. Harms are chemical burns from undiluted oil, gut burning, mint-family allergy, and avoidance in pregnancy. Many products lack the labeled main compound. (Full Review)
| Marker | Target | Why |
|---|---|---|
| ALT / AST | ALT often <25 U/L men, <19 U/L women | Phenolic oils can irritate liver in high dose |
| Fasting glucose and HbA1c | Glucose ~70–90 mg/dL; HbA1c ~4.8–5.3% | Additive glucose lowering is plausible |
| hs-CRP | <1.0 mg/L | Inflammation marker used in carvacrol and hydrosol studies |
| ApoB or fasting lipid panel | ApoB often <80 mg/dL if chasing lipid change | Particle-number lipid marker used in the hydrosol lipid study |
| Stool ova/parasites or GI PCR | Negative for the index organism | Only human outcome tied to the oil itself |
| Lactulose breath test | Fall in hydrogen/methane versus that person's baseline | Used when small intestinal bacterial overgrowth is the question |
Cadence: Baseline before a first pulse; labs when the course exceeds two weeks or glucose-lowering or anticoagulant drugs are in use; end of a 4–6 week pulse; as needed every 3–6 months if pulses repeat