Black pepper is a nearly universal spice; its main compound, piperine, is sold as a supplement to boost absorption of turmeric and other compounds. In small trials, inhaling pepper oil sharpened the swallowing reflex in older adults with swallowing problems; in one fatty-liver trial, piperine improved liver, blood-fat and blood-sugar markers. Concentrated piperine raises blood levels of several prescription medications. Seasoning amounts appear low-risk; concentrated extracts are a different exposure. (Full Review)
| Marker | Target | Why |
|---|---|---|
| ALT | Below 25 U/L | Liver-injury screen |
| AST | Below 25 U/L | Liver-injury screen |
| Total bilirubin | 0.3–1.0 mg/dL | Detects jaundice-type injury |
| Triglycerides | Below 100 mg/dL | Tracks metabolic benefit |
| LDL cholesterol | Below 100 mg/dL | Tracks lipid benefit |
| Fasting glucose | 75–90 mg/dL | Tracks glucose benefit and additive lowering |
| HbA1c | 4.8–5.4% | Longer-term glucose trend |
| Narrow-margin drug level (phenytoin, carbamazepine, tacrolimus) | Within the drug's therapeutic range (e.g., phenytoin 10–20 mg/L) | Detects piperine-driven rises |
| INR (warfarin users) | Individual prescribed target (typically 2.0–3.0) | Detects warfarin potentiation |
Cadence: Culinary pepper needs no testing. Baseline before starting a piperine extract or turmeric–piperine product; drug levels or INR at 1–2 weeks after starting or stopping; liver enzymes at 4–8 weeks, then every 3–6 months while turmeric–piperine use continues; lipids and glucose at 12 weeks, then every 6–12 months.