Heavy Metal Contamination Risks of Purified Shilajit Resin: A Hidden Threat

Abstract

Shilajit resin, an Ayurvedic exudate widely marketed as a “purified” rejuvenating agent, continues to raise safety concerns due to persistent heavy metal contamination. Despite purification claims, peer-reviewed studies and regulatory alerts indicate unsafe levels of lead (Pb), arsenic (As), mercury (Hg), and other toxic metals in several resin samples. This review evaluates evidence showing why “purified” shilajit remains potentially hazardous.

Introduction

Shilajit, a mineral pitch formed from decomposed plant and microbial matter in Himalayan rocks, is traditionally used to enhance vitality and strength. However, its mineral origin predisposes it to absorb heavy metals from the surrounding geology. Even after purification, concerns about residual contamination persist. The U.S. Food and Drug Administration (FDA) and Canadian authorities have issued warnings regarding unsafe heavy metal levels in Ayurvedic preparations, including shilajit resin [1, 2].

Evidence from Scientific Studies

Multiple analytical studies confirm heavy metal presence in shilajit samples, including those labeled “purified”:

• PubMed-indexed laser-induced breakdown spectroscopy (LIBS) analysis detected significant quantities of Pb, As, Hg, and Cu in shilajit from Himalayan regions, exceeding World Health Organization (WHO) permissible limits for dietary intake [3].

• A BMC Chemistry (2025) study reported elevated thallium (Tl) concentrations in several commercially available shilajit supplements, a metal considered even more toxic than mercury [4].

• A ResearchGate-indexed regional survey (Pakistan) found lead, chromium, and cobalt in multiple shilajit samples; though within WHO limits, researchers cautioned that chronic exposure could still pose health risks [5].

• The National Center for Biotechnology Information (NCBI) review “Shilajit: A panacea for high-altitude problems” highlights that unprocessed or improperly purified shilajit contains heavy metals, mycotoxins, and free radicals that can lead to poisoning [6].
  

ConsumerLab’s independent testing (2024) likewise found variability in heavy metal content among eight popular shilajit supplements, noting that “purified” products still require third-party validation [7].

Discussion

The persistence of heavy metals in so-called purified resin arises from:

1. Geological variability: Shilajit deposits naturally concentrate metals from surrounding rock strata.

2. Inadequate purification: Traditional and commercial purification methods reduce but rarely eliminate metallic contaminants.

3. Lack of global regulation: Supplements are not pre-approved for safety by the FDA; thus, heavy metal levels are inconsistently monitored [1].

4. Cumulative exposure: Even sub-threshold concentrations can bioaccumulate, leading to chronic toxicity—particularly hepatic and renal dysfunction [8].

5. Thallium contamination: The 2025 BMC Chemistry report underscores the presence of Tl, which causes peripheral neuropathy and organ failure [4].
   

Conclusion

Even after purification, shilajit resin remains vulnerable to heavy-metal contamination. The term “purified” lacks standardized definition or verification. Until global regulatory oversight and standardized purification protocols are established, clinicians should discourage routine use of resin forms and encourage capsule-based, lab-standardized alternatives verified by certificates of analysis (COA).

References

1. U.S. Food and Drug Administration. Public Health Advisory: Ayurvedic Products Containing Heavy Metals. FDA.gov, 2024.

2. Health Canada. Advisory—Shilajit products may contain heavy metals. Government of Canada, 2023.

3. Shah K et al. “Laser-induced breakdown spectroscopy analysis of heavy metals in shilajit.” Biol Trace Elem Res. 2021;199(2):692–700. doi:10.1007/s12011-020-02137-6.

4. Sharma P et al. “Elemental analysis of shilajit-based dietary supplements reveals elevated thallium concentrations.” BMC Chemistry. 2025;19:84. doi:10.1186/s13065-025-01384-7.

5. Iqbal M et al. “Heavy metal profile of shilajit samples obtained from Gilgit and Chellas (Pakistan).” J Ayurveda Integr Med. 2016;7(3):159-164. PMID: 305730388.

6. Agarwal SP et al. “Shilajit: A panacea for high-altitude problems.” Int J Ayurveda Res. 2010;1(1):37-42. PMID: 21829236.

7. ConsumerLab.com. Shilajit Supplements Found to Contain High Amounts of Fulvic Acid and Variable Heavy Metal Levels. 2024.
   

World Health Organization. Guidelines for Assessing Quality of Herbal Medicines with Reference to Contaminants and Residues. WHO Press, 2011.