A Chilean berry rich in the deep purple pigment delphinidin. Two claims rest on human testing: a standardized extract raises tear production and eases dry, tired eyes, and a dose before a meal blunts the blood sugar and insulin rise that follows. Trials are small and short, mostly run by the sellers; no side effect has been documented. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Fasting glucose | 75–90 mg/dL | Primary metabolic target of the extract |
| HbA1c | 4.8–5.4% | Average glucose exposure over ~3 months |
| Fasting insulin | 2–6 µIU/mL | Detects compensation masking normal glucose |
| HOMA-IR | < 1.5 | Insulin resistance index |
| hs-CRP | < 1.0 mg/L | General inflammation, secondary target |
| Oxidized LDL | No established target; track change from own baseline | The marker that moved in the oxidative stress trial |
| LDL cholesterol | < 100 mg/dL, lower with risk factors | Secondary outcome in the three-month trial |
| Schirmer's test | > 10 mm in 5 minutes | Objective tear production, primary ocular endpoint |
| Tear break-up time | > 10 seconds | Tear film stability, complements Schirmer's |
| Ferritin | 50–100 ng/mL (women), 50–150 ng/mL (men) | Iron stores, the one plausible depletion risk |
Cadence: Baseline, then metabolic panel at 12 weeks and every 6–12 months during continued use; tear measurements at 8 weeks; ferritin annually.