Chaga is a birch fungus taken as tea or capsule. Laboratory and rodent work shows immune, blood-sugar, and antioxidant activity, but no controlled human trial of chaga alone has reported a health outcome. Against that sits a documented harm: chaga is unusually rich in oxalate, a crystal-forming compound, and sustained high daily intake has caused kidney damage requiring dialysis. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Serum creatinine | 0.7–1.0 mg/dL (men), 0.6–0.9 mg/dL (women) | Detects falling kidney clearance |
| eGFR | Above 90 mL/min/1.73 m² | Direct estimate of filtering capacity |
| Cystatin C | 0.6–0.9 mg/L | Filtration measure unaffected by muscle mass |
| 24-hour urine oxalate | Below 25 mg/24 h | Quantifies the load chaga adds |
| Urine microscopy | No numeric target — presence versus absence of calcium-oxalate crystals against own baseline | Earliest visible sign of crystal deposition |
| Fasting glucose | 75–86 mg/dL | Baseline against which any metabolic effect is judged |
| HbA1c | 4.8–5.3% | Average blood sugar over roughly three months |
| hs-CRP | Below 0.8 mg/L | Tracks the inflammatory direction of an immune-active supplement |
| ALT | 10–26 U/L | Screens for liver strain from concentrated extracts |
| Urine specific gravity | 1.005–1.015 | Confirms urine is dilute enough to resist crystal formation |
Cadence: Baseline before the first serving; kidney markers at 4 weeks, 3 months, then every 6 months while daily intake continues; urine oxalate annually; metabolic markers at 3 months.