Is Shilajit Safe? The Heavy Metals Question

Raw shilajit is scraped from rock, and rock contains metals. Untested shilajit can carry lead, arsenic, mercury and cadmium, and published analyses have found them above permissible limits in commercial samples. Purified and tested shilajit is a different product: the EU sets maximum levels for lead, cadmium and mercury in food supplements, and a batch-specific laboratory report shows whether a jar sits under them. The one we sell does, by a wide margin, and the report is linked from the product page. Whether shilajit is safe is therefore not one question but two: is this particular jar clean, and are you someone who should be taking it at all.

This is the article that matters most in the category and the one most shops skip. It gives the actual legal limits from the regulation, the literature on what raw and commercial shilajit has been found to contain, one real certificate compared against the limits line by line, and a checklist for reading any report a seller sends you.

Why contamination is the default, not the exception

Shilajit is a humic exudate that has sat in mineral rock for centuries, and it carries what the rock carried. That is not a defect in an otherwise clean category. It is the starting condition of the raw material, which is why Ayurveda developed a purification step for it long before anyone could measure lead in parts per million.

The literature bears this out. A 2022 study in Biological Trace Element Research by Aldakheel and colleagues analysed the two kinds of shilajit most widely sold, from India and Pakistan, by three independent methods: laser-induced breakdown spectroscopy, ICP-OES/MS and EDX. Both samples were rich in calcium, sulphur and potassium, and both contained aluminium, strontium, manganese, barium, zinc, nickel, boron, chromium, lead and arsenic “in amounts that exceeded the standard permissible limit”, with mercury detected in the Indian sample. The authors describe the work as significant “for creating awareness among people suffering due to overdose of this product”. That is two commercial samples, not a survey of the market, but it is exactly what an unpurified or poorly purified material looks like under a spectrometer.

A 2025 study in BMC Chemistry by Kamgar and colleagues looked at a metal no regulation limits in supplements: thallium. Using anodic stripping voltammetry, they measured thallium in natural shilajit from several countries at up to 0.226 micrograms per gram, and in commercial shilajit supplements at up to 0.5 micrograms per gram. The finding that matters is the comparison: “the concentration of thallium in some supplements was higher than in crude Shilajit”. Processing had concentrated it, or introduced it, rather than removing it. One pill of the worst supplement delivered up to 0.095 micrograms of thallium, which is a small number, but the authors’ concern was long-term daily consumption, and thallium is not on any standard certificate.

The same group’s 2026 paper in the Journal of Trace Elements in Medicine and Biology ran twelve samples from different origins through ICP-MS and found wide variability in the toxic elements, including cobalt, nickel, lead, cadmium and mercury, though in those twelve samples “toxic metals were present below established toxicity thresholds”. Two conclusions sit side by side in that literature. Origin decides a great deal, so two honest jars genuinely differ. And the processing step can make things worse as well as better, so purification without testing is a story, not a result.

What purification does and does not do

The traditional process is shodhana. The raw material is dissolved in water, sometimes with herbal decoctions, the rock, sand and plant debris that do not dissolve are filtered out, and the clear liquid is slowly reduced, traditionally in the sun and now at low heat, back to a resin. A modern producer does the same thing with filter grades and controlled temperatures. Done properly, it removes the insoluble matter, which is where a large part of the grit and a portion of the mineral load sits.

It does not remove what dissolves. Metals bound to the small organic molecules that make shilajit what it is travel with them through the filter. The 2026 ICP-MS study found most metals in shilajit associated with low molecular weight complexes, which is to say the fraction that dissolves and stays. Purification is necessary. It is not sufficient, and a jar that says “purified” and shows no test result has told you half of what you need to know.

Modern practice adds the second half: the finished batch is sent to a laboratory, each metal is measured, and the result is written down with a batch reference. Everything below is about reading that document.

The EU maximum levels, from the regulation itself

Shilajit is sold in the EU as a food supplement, and the contaminants regulation for food is Commission Regulation (EU) 2023/915 of 25 April 2023, which replaced Regulation (EC) No 1881/2006. Article 9 states plainly that “Regulation (EC) No 1881/2006 is repealed”, so anyone still quoting the 2006 numbers is quoting a document that no longer applies, even though for these three metals the figures carried across unchanged. Annex I of the 2023 regulation sets these maximum levels for food supplements:

Contaminant	Annex I point	Maximum level in food supplements
Lead	3.1.28	3.0 mg/kg
Cadmium	3.2.21.1	1.0 mg/kg
Cadmium, supplements at least 80 per cent dried seaweed, seaweed products or dried bivalve molluscs	3.2.21.2	3.0 mg/kg
Mercury	3.3.2	0.10 mg/kg
Inorganic arsenic	3.4	no food supplement entry: the limits apply to rice and rice products, infant formulae, baby food and fruit juices

Three things to notice. The cadmium exception for seaweed-based supplements is why a sea moss or bladderwrack capsule can legally carry three times the cadmium of a shilajit resin, which is worth knowing if you buy both. There is no inorganic arsenic limit for food supplements at all; the arsenic rows in the regulation are about rice, infant food and fruit juice, so a certificate that reports arsenic is reporting it against the laboratory’s own reference or a foreign standard, not an EU legal limit. And there is no entry for thallium anywhere in the table, which is why the 2025 BMC Chemistry paper matters: the metal the recent literature worries about is the one nobody is required to test for.

In Great Britain the retained version of the 2006 regulation applies with the same three figures for supplements: lead 3.0, cadmium 1.0 (3.0 for seaweed-based), mercury 0.1 mg/kg. So for a buyer anywhere in Europe the numbers to hold in your head are three, one and a tenth.

One real certificate, compared line by line

Here is what a batch report looks like when it is done properly, using our supplier’s laboratory certificate for the shilajit resin we sell. It was issued in February 2026 by an accredited laboratory, the analysis is stated as accredited to ISO 17025:2017, the sample is identified as shilajit resin with a laboratory reference, and the metals were measured by ICP-MS.

Metal	Certificate result	EU maximum for food supplements	Margin
Lead	0.44 mg/kg	3.0 mg/kg	about one seventh of the limit
Cadmium	below 0.2 mg/kg (not detected at the reporting limit)	1.0 mg/kg	at least five times under
Mercury	0.03 mg/kg	0.10 mg/kg	under a third of the limit
Arsenic	0.02 mg/kg	no EU limit for supplements	reported for completeness

The same document reports aflatoxins below 0.1 ppb, pesticides not detected, and microbiology within the USP <2021> and <2022> limits for dietary supplements, alongside the composition figures discussed in the definition article: 73.8 per cent fulvic acid, 14.7 per cent humic acid, 14.3 per cent moisture and 11.8 per cent ash.

Read the table honestly. Lead at 0.44 mg/kg is not zero; it is a real, measured presence at about a seventh of the legal ceiling, which for a material that has spent centuries in rock is a good result and not a miraculous one. Cadmium was not detected, but the reporting limit was 0.2 mg/kg, so the honest statement is “below 0.2”, not “free of cadmium”. Mercury and arsenic were measured at levels close to the bottom of what the method resolves.

What the certificate does not cover matters as much. It describes the resin, and only the resin. Our capsule blends are separate products with other ingredients and have no third-party test of their own, which we say on their pages rather than borrowing the resin’s report for them. And it describes one batch: a certificate is a statement about the material that was tested, and a seller who shows a two-year-old PDF for a jar filled last month is showing you history.

What a proper lab report has to say

A certificate of analysis is only useful if it is specific. Before you trust one, look for every item on this list.

1. Each metal named, with a measured value. Lead, cadmium, mercury and arsenic at minimum. “Heavy metals: pass” is not a result. “Lead: 0.44 mg/kg” is.
2. A detection or reporting limit. “Not detected” means nothing without the limit at which the method stops seeing. Below 0.2 mg/kg and below 0.002 mg/kg are very different claims.
3. The method. ICP-MS is the standard for trace metals. A certificate that names no method is a certificate that could have been typed by anyone.
4. A batch or lot reference that matches the jar. This is the item most often missing. A report without one describes some shilajit, somewhere, once.
5. The laboratory’s name and accreditation. ISO 17025 is the international standard for testing laboratories. A named, accredited third party is the difference between a test and a claim.
6. A date, and a sensible one. Resin is stable, but a certificate older than the batch it supposedly covers is not covering it.
7. The limits it is compared against. A good report states the reference, whether that is Regulation (EU) 2023/915, a pharmacopoeia or the laboratory’s own specification, so you know what “pass” means.

If a seller cannot or will not send this document, that is your answer. A purification story, a mountain range and the words “lab tested” without the PDF are marketing. The rest of the buying checklist, including the things you can check on the jar itself, is in how to spot real shilajit, and the European sellers who publish reports are the subject of where to buy shilajit in Europe.

Why the limits are not zero, and what a margin means

Lead, cadmium and mercury are in soil, water and every plant grown in them. The regulation sets levels “at a strict level, which is reasonably achievable by following good agricultural, fishery and manufacturing practices”, in its own words, rather than demanding an absence that no food could meet. A supplement that reports zero for every metal at a very low detection limit is either extraordinarily clean or reporting badly, and the second is more common.

The margin matters more than the pass. A lead result at 2.9 mg/kg passes the regulation and is a jar we would not sell; at a typical 300 mg daily dose it is still a small absolute intake, but it tells you the material was not well purified and that the next batch may not pass. A result at 0.44 mg/kg tells you the process works with room to spare. When you compare two certificates, compare the numbers, not the verdicts.

What a daily dose actually delivers

Maximum levels are written per kilogram of product, and nobody eats a kilogram of shilajit. The arithmetic for a real serving is worth doing once, because it is the arithmetic a regulator does. At a typical resin dose of 300 mg per day, a batch at the lead ceiling of 3.0 mg/kg delivers 0.9 micrograms of lead a day. Our certificate’s 0.44 mg/kg delivers about 0.13 micrograms. For mercury, the ceiling of 0.10 mg/kg is 0.03 micrograms in a 300 mg dose and the certificate’s 0.03 mg/kg is 0.009 micrograms. These are small absolute quantities, which is why the regulation can tolerate a non-zero level, and they are also why the margin between a result and the ceiling matters more than the pass mark: the regulation is written for a whole diet, and a supplement is one contribution to it, taken every day for months.

That is also the reason a low reporting limit is worth paying for. A laboratory that reports cadmium as “below 0.2 mg/kg” has told you the batch is under the limit by a factor of five. One that reports “below 0.01 mg/kg” has told you something twenty times more precise about the same jar.

If your jar came without a certificate

Ask the seller for one, by batch number, in writing. A serious seller has it and sends it the same day. If the answer is a stock PDF with no batch, a screenshot with no laboratory name, or a paragraph about the mountains, treat the jar as untested, because it is. The published analyses above are what untested commercial shilajit has looked like when somebody finally measured it, and they are not reassuring.

Do not try to test it yourself with a flame or a water test; those checks, covered in how to spot real shilajit, can tell you whether a resin is resin, and nothing about metals. Metals are measured by a spectrometer or not at all.

Who should still not take it

A clean certificate settles the contamination question. It does not make shilajit appropriate for everyone.

Iron-overload conditions. Shilajit is iron-bearing, and iron is not a contaminant in this material, it is a constituent. In a 91 day rat study in the Asian Pacific Journal of Tropical Biomedicine, liver iron was raised in the group given 5,000 mg/kg, the highest dose. The NHS describes haemochromatosis as an inherited condition in which iron builds up over many years and can damage the liver, joints, pancreas and heart. Anyone with haemochromatosis or another iron-overload diagnosis should not take shilajit, however clean the batch.

Pregnancy and breastfeeding. No trial has recruited pregnant women, and a published case report links six months of mumijo in pregnancy to a licorice-like syndrome. Avoid.

Children. Not tested. Not for them.

Prescribed medication. No interaction studies exist. Ask a doctor or pharmacist first.

Shilajit is not authorised for any health claim in the EU, and nothing on this page should be read as suggesting it acts on any condition. Its side effects in trials, mostly mild digestive complaints, and the case reports that exist are in shilajit side effects.

The short version

Untested shilajit can carry lead, arsenic and mercury above permissible limits, and processing can concentrate thallium rather than remove it. The EU limits for food supplements are 3.0 mg/kg lead, 1.0 mg/kg cadmium and 0.10 mg/kg mercury, with no supplement limit for arsenic or thallium. A proper certificate names each metal, its value, its detection limit, the method, the laboratory and the batch. Ours reports lead at 0.44, cadmium below 0.2, mercury at 0.03 and arsenic at 0.02 mg/kg, and it covers the resin only. Read the numbers, not the verdict, and if a seller has no numbers, buy elsewhere.

Once the jar is clean, the next question is practical: how to take it. And if you want to know what the fulvic and humic percentages on the same certificate mean, what is fulvic acid is where that is explained.