Oligomeric proanthocyanidins are plant-pigment compounds sold as grape seed and pine bark extract dietary supplements for blood-vessel and blood-sugar health. Small trials report modest drops in blood pressure and blood sugar, less leg swelling, less joint pain and fewer hot flashes. Side effects are mild; effects can add to blood-thinning, blood-pressure and diabetes medications. Most trials are small, short and maker-funded; aging-cell clearing is shown only in mice. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Blood pressure (home, seated) | Systolic below 120 mmHg | Expected to change; safety check with blood-pressure drugs |
| Fasting glucose | 70–99 mg/dL | Expected to change; safety check with diabetes drugs |
| HbA1c | 4.0–5.6% | Expected to change in diabetes |
| LDL cholesterol | No established target for OPC use; track change from own baseline | Expected to change (small, inconsistent) |
| High-sensitivity C-reactive protein | No established target for OPC use; track change from own baseline | Expected to change (unvalidated marker) |
| Ferritin | About 24–336 ng/mL (men), 11–307 ng/mL (women) | Safety check (iron absorption) |
| INR (warfarin users only) | Within the prescriber's therapeutic range | Safety check (bleeding) |
Cadence: Home blood pressure weekly for 4 weeks, then monthly; fasting glucose, HbA1c, lipids and C-reactive protein at 3 months, then every 6–12 months; ferritin every 6–12 months for those at risk; INR within 1–2 weeks of starting or stopping OPCs (warfarin users)