Why heavy metals are an unavoidable conversation in shilajit

Shilajit is a geological exudate — a black, resinous compound that seeps from the cracks of high-altitude Himalayan rock during summer warming. Because it forms in direct contact with mineral-bearing rock at altitudes between 14,000 and 18,000 feet, its mineral inheritance reflects exactly the local geology. That is part of what gives authentic Himalayan shilajit its distinctive composition. It is also the reason heavy metals — at trace levels — are unavoidable in any honest shilajit sample.

The chemistry literature confirms this. Carrasco-Gallardo et al. 2012 (PMID 22482077) describes shilajit as a complex natural phytocomplex rich in fulvic acid, dibenzo-alpha-pyrones, humins, trace minerals and organic compounds carried up from the rock matrix. Stohs 2014 (PMID 23733436) reviews the safety profile of properly sourced and purified shilajit and concludes it is safe at recommended doses — but explicitly flags heavy-metal and free-radical contamination from improperly sourced or insufficiently purified material as the dominant safety risk in the global market.

The honest framing for an Indian buyer in 2026 is therefore not "is there any metal at all?" — there always is, just as there is in spinach, brown rice, or sea fish. The question is whether a specific batch tests at or below pharmacopeial limits, and whether the testing was done by a third party who has no commercial reason to lie about it.

The four standard metals — what every shilajit COA should already report

The Indian Ayurvedic Pharmacopoeia (API) and the broader Ayurvedic herbal pharmacopeial framework specify limits for four primary heavy metals in finished herbal products. These are the minimum any credible shilajit COA must report:

• Lead (Pb) — the highest-volume historical contaminant in herbal supplements globally; well-characterised neurotoxic profile in chronic exposure.
• Arsenic (As) — present in Indian groundwater and some mineral-rich soils; tested as total arsenic, sometimes speciated into inorganic / organic forms.
• Mercury (Hg) — historically a concern from amalgamation and certain traditional preparations; essentially non-existent in properly sourced raw resin but tested as a control.
• Cadmium (Cd) — present at trace levels in some mineral matrices; tested against API limits.

Each metal has a pharmacopeial maximum, typically expressed in parts per million (ppm) of the finished product. An accredited lab quantifies the actual measured level using ICP-MS or equivalent and compares it to the limit. A batch passes only if it sits at or below the limit on every metal — a single failure on any one is a fail.

Our published Certificate of Analysis for batch B023724DC25 shows "Pass" on lead, arsenic, mercury and cadmium against API limits. You can read the full certificate on our Lab Results archive, which also publishes the analytical-report (A.R.) number you can use to verify the report independently with Eurofins.

The fifth metal — why 2025 changed the panel

In 2025 a peer-reviewed paper in BMC Chemistry by Kamgar et al. (PMID 39827344) reported on the toxic-element profile of commercial shilajit samples sourced from the Indian market. Alongside the four standard heavy metals, the investigators specifically screened for thallium (Tl) — a metal that is rarely on default Ayurvedic herbal panels but is well documented as a contaminant of certain mineral-rich substrates.

The paper detected measurable thallium across several of the commercial samples tested. That single result is significant for two reasons. First, thallium is highly toxic at very low concentrations — it has historically been used as a rodenticide and is no longer permitted in agricultural use in most jurisdictions because of its toxicity profile. Second, thallium is not part of the default API herbal-product panel, which means a shilajit batch could clear "all heavy metals tested" on a conventional panel and still carry thallium that was simply never measured.

From 2025 onward, the responsible position for any Indian shilajit brand is to add thallium to the panel. Not because the API specification formally requires it yet, but because the published research has moved — and a credible 2026 product can no longer hide behind a four-metal report when the fifth metal has been documented in the same market.

Our long-form explanation of the Kamgar paper, including what it measured and what it does and does not claim, is at Thallium in Shilajit — What the 2025 Research Shows.

What most Indian shilajit COAs do not show

If you read a sample of public Certificates of Analysis from Indian shilajit brands available in 2026, three patterns recur:

1. No third-party lab is named. The certificate is on a brand letterhead with no external accredited laboratory or A.R. number. There is no audit path — only the brand's word.
2. Only four metals are reported. Lead, arsenic, mercury, cadmium — the older standard. No thallium. From 2025 onward, that is an open gap rather than a passing grade.
3. Fulvic acid is "reported" without a method. A number like "high" or "above 75%" appears, but no analytical method (for example, API spectrophotometric quantification) is named. A number without a method is a marketing claim, not a measurement.

None of these patterns mean a product is unsafe — they mean the safety claim is unverifiable. For a substance whose entire health proposition depends on what is in the bottle, that is the same thing in practice.

For a full buyer's checklist on reading a shilajit COA — what a credible certificate must contain, line by line — see the Lab Results page, which includes a section called How to Read a Shilajit COA.

What our Eurofins panel reports

The Yeti Life's testing partner is Eurofins India, a third-party accredited analytical laboratory in Bangalore. For every batch we release, Eurofins runs the full pharmacopeial panel against the Indian Ayurvedic Pharmacopoeia (API) specification:

• Fulvic acid (API spectrophotometric method) — quantified to a number, with the method named on the certificate.
• Heavy metals (five-metal panel from 2025 onward) — lead, arsenic, mercury, cadmium against API limits, plus thallium against a conservative published threshold per the Kamgar standard.
• Microbial contamination — total plate count plus key pathogens (Salmonella, E. coli, yeasts and molds) against the API standard.
• Dibenzo-alpha-pyrone authenticity markers — the chromoprotein complex that Ghosal 1991 (PMID 1921793) identified as the specific compound separating real shilajit from humic-acid powders and peat substitutes.

A batch only enters the public archive after every line clears testing. Failed batches are destroyed, not downgraded or sold under a different brand.

Methodology & what this review does not claim

This review does not present a head-to-head comparison of competing Indian shilajit brands' lab data. We have not laboratory-tested competitor resin ourselves, and we will not publish numbers we have not measured. What we do publish is two things: (a) our own complete Eurofins panel for every batch we release, and (b) summaries of published peer-reviewed work — most importantly the 2025 Kamgar thallium paper above — with direct PubMed links so any reader can verify our framing against the original source.

The single quantitative claim we will make is the one we can support with documents you can audit: for batch B023724DC25, every metal on the four-metal API panel clears the corresponding pharmacopeial limit, and our 2025-onward cadence adds thallium to the panel per the Kamgar standard. The certificate carrying these results is on this site, and the A.R. number on it can be verified directly with Eurofins.

What to ask any brand you are considering

1. Is the lab named? Is it third-party and accredited? Is there an A.R. number on the certificate?
2. Does the COA match the specific batch number printed on the jar — not a generic brand-level certificate?
3. Are the four standard metals (lead, arsenic, mercury, cadmium) tested against named API limits — and is thallium also reported?
4. Is fulvic acid quantified with a named method (for example, spectrophotometric), or just described in marketing language?
5. Is there a published certificate for the batch you are buying, or only for last year's batch?

If a brand cannot answer those five questions with documents, the rest of the marketing copy does not matter — there is nothing to audit.

Frequently asked questions