Shilajit and heavy metals: lead, arsenic, mercury

Shilajit seeps out of rock, and it carries some of that rock’s metals with it. That includes useful minerals such as calcium, magnesium, iron and zinc, but also toxic ones: lead, arsenic, mercury, cadmium and thallium. Whether a particular jar is safe depends on where the shilajit was collected, how it was processed and whether anyone checked.

The research is genuinely mixed. Some careful analyses found toxic metals below safety thresholds; others found them well above. That inconsistency is the point: you cannot tell from the label, the price or the country of origin. You can only tell from a lab test of the batch.

Which heavy metals have been found in shilajit?

A 2024 review counted around 65 metals reported in shilajit, including toxic ones such as lead, arsenic, cadmium, mercury, aluminium and copper. It concluded that levels were usually below the limits set by the WHO and US FDA for herbal medicines, “except in few studies where exceeded levels were reported”, and that taking shilajit “without knowing permissible levels of metals is not safe” (Hussain and Saeed, 2024).

Here is what individual studies found:

To put the mercury result in context: 0.76 µg/g is the same as 0.76 mg/kg, more than seven times the GB legal maximum of 0.10 mg/kg for food supplements. That was a single product tested over a decade ago, so it says nothing about any brand on sale today. It does show that contaminated shilajit has reached the online market.

Does purified shilajit have fewer heavy metals?

Not necessarily. Purification removes sand, soil and plant debris, but metals bound to the humic substances in shilajit can stay. In the 2025 thallium study, some finished supplements contained more thallium than crude shilajit, and the authors called for “regular monitoring and standardized testing” (Kamgar et al., 2025). A 2026 analysis found that most metals in shilajit are bound to small molecules under 10 kDa, the same size range as humic acid and metal complexes (Kamgar et al., 2026), which helps explain why they are hard to wash out.

You will also see claims that the fulvic and humic acids in shilajit “detox” heavy metals. The 2024 review discussed this idea but concluded that the data on metal detoxification “still needs to be clarified” (Hussain and Saeed, 2024). Don’t rely on it.

Why does a small amount of lead matter?

Because it builds up. A tiny amount taken daily for months adds to the body’s total burden in a way a one-off dose does not. The harm from contaminated traditional remedies is well documented:

• A 2002 systematic review from the University of Exeter found 15 case reports and 6 case series of serious harm from heavy metals in traditional Indian remedies, mostly lead (Ernst, 2002).
• An Indian hospital found 73 people with lead poisoning from Ayurvedic medicines among patients investigated for unexplained stomach pain. All had anaemia and abnormal liver tests; some had high blood pressure, nerve symptoms or kidney injury (Mehta et al., 2017).
• In New York in 2011 to 2012, six pregnant women were found to have lead poisoning linked to Ayurvedic medicines made in India, some of which were up to 2.4% lead (CDC, 2012).
• Lead also raises uric acid. In a large US survey, people with the highest blood lead levels, still within the range then considered acceptable, had a 3.6-fold higher risk of gout than those with the lowest (Krishnan et al., 2012). See shilajit, gout and uric acid.

None of these reports singled out shilajit, but shilajit is sold through the same channels, often by the same suppliers.

What are the legal limits in the UK?

In Great Britain, food supplements must not exceed these maximum levels, measured in the product as sold (Regulation 1881/2006, as retained in UK law):

The right-hand column is simple arithmetic (limit multiplied by 0.5 g) to show the scale. A product that meets the limits contributes very little; one that exceeds them could contribute many times more. Shilajit bought from overseas sellers on marketplaces may never have been tested against these limits at all. Our UK legal status page explains how shilajit is regulated.

How can I check a shilajit product for heavy metals?

Ask the seller for a certificate of analysis (CoA) for the batch number printed on your jar, not a generic or years-old one. A useful certificate:

• comes from an independent, accredited laboratory, not the seller;
• reports actual results for lead, arsenic, cadmium and mercury, ideally by ICP-MS;
• gives results in mg/kg (or ppm, which is the same thing) so you can compare them with the GB limits above;
• names the lab and the date, so you could check it.

If a seller cannot or will not provide one, buy elsewhere. Our guide to reading a certificate of analysis walks through a real example, and raw vs purified shilajit explains why raw resin carries the most uncertainty.

Who is most at risk from heavy metals in shilajit?

Pregnant women, because lead exposure before birth can affect a baby’s brain development and growth (CDC, 2012); breastfeeding women and children, as a precaution; people with kidney disease, also as a precaution, since lead poisoning can damage the kidneys (Mehta et al., 2017); and anyone taking shilajit daily for many months. If you have taken an untested product and have symptoms such as stomach pain, constipation, tiredness or pallor, tell your GP, who can arrange a blood lead test. For a broader view of risks, see our safety overview.