Black seed oil, a plant oil supplement sold for heart and metabolic health, offers adults tracking their numbers small, measurable, low-cost improvements in blood pressure, cholesterol, blood sugar and weight, especially when values start elevated. Confidence in nearly all findings is low or very low; no study measured heart attacks, strokes or lifespan. Concerns include mild digestive discomfort, rare kidney and liver injury, severe topical skin reactions and drug interactions. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Blood pressure (home) | <120/80 mmHg | Main cardiovascular benefit; additive lowering |
| Fasting glucose | 75–90 mg/dL | Glucose benefit; hypoglycemia risk |
| HbA1c | <5.4% | Three-month glucose trend |
| LDL cholesterol and ApoB | LDL <100 mg/dL; ApoB <80 mg/dL | Lipid benefit |
| Triglycerides | <100 mg/dL | Lipid benefit |
| hs-CRP | <1.0 mg/L | Inflammation marker |
| Creatinine, eGFR and urea | eGFR >90; creatinine within 0.3 mg/dL of baseline | Kidney safety |
| ALT and AST | ALT <25 U/L; AST <25 U/L | Liver safety |
| INR (warfarin users only) | Stable in clinician-set range (usually 2.0–3.0) | CYP2C9 interaction |
| Phenytoin or immunosuppressant level | Baseline record | Drug interaction |
| TSH and anti-TPO (thyroid autoimmunity only) | TSH 1.0–2.5 mIU/L | Thyroid effect |
Cadence: Baseline; blood pressure weekly for the first month; INR 1–2 weeks after starting (warfarin users); repeat at 12 weeks, then every 6–12 months