Supplement analysis backed by scientific evidence · PT

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Limited evidenceLongevity & antioxidants

Chaga Mushroom

No completed human efficacy trial exists for chaga in any indication, while multiple case reports document kidney failure from oxalate accumulation. This is one of the few supplements where the documented harms clearly outweigh the documented benefits.

What the science says

  • Antioxidant, anticancer, and immune effects Limited evidence

    Every claim rests on cell-culture and rodent work on betulinic acid, inotodiol, and polysaccharide fractions. There is no published randomized controlled trial of chaga in humans for cancer, immunity, inflammation, fatigue, or blood sugar — the entire consumer case is preclinical extrapolation.

  • Oxalate nephropathy and kidney failure Moderate evidence

    This is the best-documented human effect of chaga, and it is a harm. A 2022 case report describes biopsy-confirmed oxalate nephropathy presenting as nephrotic syndrome after chaga use, and a 2020 report describes a patient who progressed to end-stage renal disease requiring dialysis after long-term chaga ingestion, alongside a review of similar published cases. Chaga is exceptionally high in oxalate — measured around 14% by dry weight in some samples.

  • Blood sugar control Limited evidence

    Rodent studies show hypoglycemic effects from chaga extracts, and there are no human data at all. Do not rely on chaga for glycemic control or use it as a reason to alter diabetes medication.

Dosage & safety

Studied doseNo established dose. Commercial products supply roughly 1-3 g/day of dried mushroom or extract. Because the published cases of nephropathy involved doses in exactly that range taken over months, 'typical' consumer use cannot be described as demonstrably safe.
SafetyOxalate nephropathy and end-stage renal disease have been reported repeatedly. Avoid chaga entirely if you have chronic kidney disease, reduced GFR, or a history of calcium oxalate kidney stones, and do not use it at high doses long-term under any circumstances. Chaga also shows antiplatelet activity (caution with anticoagulants and before surgery) and may lower blood glucose additively with antidiabetic drugs. Wild-harvested birch conk concentrates heavy metals from its substrate. Avoid in pregnancy and breastfeeding — no safety data exist.

Scientific references

Where to buy

Micro Ingredients, Organic Chaga Mushroom Extract, 10 oz (283 g)

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