Antioxidant, cytotoxic and adsorption activity of Karelian shungite

Skrypnik, Babich and colleagues find that Karelian shungite shows significant antioxidant, cytotoxic and adsorption capabilities. They argue this combination of absorptive, catalytic, antibacterial and regenerating functions makes shungite a candidate material for water purification.

Sources: via verifiedshungite.com · original on Consensus .

Edited 2026-05-03, source audit. Cited sources verified to exist; no fabricated sources detected. Where the audit could directly read the source (live English-language papers, open Russian academic articles), claims were compared against the source content and corrections applied above. Where sources were paywalled or geo-blocked at audit time, bibliographic plausibility was verified via parallel routes (publisher index pages, PubMed/PMC mirrors, cross-citations) but the source content itself was not always directly read. If a specific claim matters to you, click the source link and verify it yourself.

Here's the direct primary for this one (Skrypnik et al., Antioxidants, 2021, open access) with the actual measured numbers - and they're refreshingly honest, which makes them more trustworthy, not less.

Antioxidant strength, quantified

The researchers measured shungite's radical-scavenging power and reported it in the standard equivalents chemists use. The best sample (20 µm, heat-treated) came in at:
- 1.63 mg/g ascorbic-acid (vitamin C) equivalents
- 2.19 mg/g trolox (vitamin-E analogue) equivalents
- 1.11 mg/g quercetin equivalents

The honest framing the authors give: shungite's antioxidant action is real and measurable, but on a per-gram basis it's "approximately 1000 times less pronounced than quercetin" (one of the strongest plant antioxidants). So it's a genuine, gentle, slow-release radical scavenger - not a megadose. For a rock you put in water, measurable vitamin-C-equivalent activity at all is the interesting part.

Particle size and heat-treatment matter

Finer particles (20 µm) and a heat-treatment step both raised the activity - the same "smaller and activated works harder" pattern that shows up across the shungite literature.

Cytotoxicity

Tested on HEK293 human cells (Alamar Blue method). The heat-treated 20 µm sample showed the most cytotoxic activity of the samples - a reminder that "natural" and "inert" aren't the same thing, and that dose and particle size are real variables.

(The same paper's mycotoxin-adsorption results - aflatoxin, ochratoxin and four others bound at 81-100% - are covered in their own thread on this forum.)

Source

- Skrypnik L. et al. (2021), "A Study of the Antioxidant, Cytotoxic Activity and Adsorption Properties of Karelian Shungite by Physicochemical Methods", Antioxidants (Basel) 10(7):1121: pmc.ncbi.nlm.nih.gov