Filed August 13, 2026 · Updated October 12, 2026
Chaga, oxalates, and what the case reports actually say
Two of our four blends contain chaga. Here is the honest version of the safety question nobody in the category brings up first.
Chaga is unusually rich in oxalates — compounds that, in high chronic doses, are hard on kidneys. This is not a rumor; it is in the literature. The most-cited report (Kikuchi et al., Clinical Nephrology, 2014) describes oxalate nephropathy in a patient who had taken chaga powder daily for years, at an estimated four to five grams of raw powder per day.
The details of that case matter more than its headline. Four to five grams daily of raw powder, sustained for years, is a very different exposure from what a cup of Brewlune contains: 300mg — about one-fifteenth of that daily amount — of hot-water extract rather than raw ground fungus. Extraction changes the arithmetic, and dose is the whole question. But "different exposure class" is not the same as "zero," and we would rather print the distinction than hope nobody asks.
What we do about it: the chaga dose in Dawn Patrol, Point Break, and Last Light is deliberately the smallest line on those placards, the extract is hot-water (the preparation used in most published work), and the per-batch COA program covers heavy metals and contaminants on every batch. If you have a history of kidney stones or kidney disease, this is the ingredient to ask your clinician about — that is not a legal reflex, it is the honest reading of the case reports.
Why write this at all? Because the front-of-bag rule only means something if it survives the unflattering facts. A dose table that only carries the good news is a proprietary blend with better typography.
See the chaga evidence grade and Brewlune’s per-serving recipe amount alongside the study type and its limits.
Sources
- Kikuchi Y, et al. Chaga mushroom-induced oxalate nephropathy. Clinical Nephrology, 2014;81(6):440-444.
- Real Mushrooms chaga extract specification: wild sclerotia, hot-water extract, >8% beta-glucans (supplier minimum) — see /sourcing for the full supply chain.
