Shilajit Safety: Side Effects, Heavy Metals, Thallium and Who Should Avoid It

Shilajit is sold as "natural" and "ancient", and both words lull people into skipping the question that matters before any supplement: what could go wrong? For shilajit the honest answer has two parts. The first is the ordinary list of side effects and cautions that comes with any active substance: stomach upset, allergic reactions, and groups of people who should stay away. The second is more specific to this ingredient. Shilajit forms in rock, and rock contains metals. Whether a given jar is harmless or hazardous depends less on shilajit itself than on where it was collected, how it was processed, and whether anyone tested it.

This guide brings together what the published research and expert guidance actually say about shilajit safety: the reported side effects, the laboratory analyses of heavy metals including a 2025 study of thallium, the independent product tests, the groups advised to avoid it, and the limits of what is known about long-term use. It also corrects several statements that appeared on our own earlier pages and says where our own product stands.

It is one of five connected guides. For the overview see the complete shilajit guide, for doses see the dosage guide, and for choosing a product see the buying guide.

Where safety information on shilajit comes from

Safety evidence comes in four grades, and it helps to keep them separate. The strongest is a randomised trial that records adverse events. For shilajit these exist, but they are small. The second is case reports, which describe individual people who had a problem after taking a product. They cannot tell us how common a problem is but they can flag one that trials would miss. The third is laboratory analysis of products, which measures what is in them. For shilajit this is the most informative category, because the main concern is what the product contains. The fourth is expert guidance, in which clinicians and reviewers draw on the first three plus mechanism and experience to say who should be cautious.

No regulator has published a safety assessment of shilajit that we could find. In most countries it is sold as a supplement or food, and a supplement's maker is generally responsible for its safety without pre-market review. Our buying guide explains how this works in the United States, the United Kingdom and Canada. The practical consequence is stated by Cleveland Clinic: with supplements, "you can't know for sure what you're taking", unless someone has tested it and shown you the result.

What side effects have been reported

Table 1 lists the side effects and cautions we could trace to a source, with the strength of the evidence for each. We give the source in every case, because several items that appear on seller pages without a source turned out to be either exaggerated or unsupported.

Two corrections are needed against earlier versions of this site. First, we previously wrote that hormonal effects in women, such as acne and irregular periods, were "more strongly associated with unregulated or adulterated products than with pure shilajit". We found no source for that. The source we did find, Cleveland Clinic, attributes those effects to a possible rise in testosterone, which would be a property of the substance itself. Second, we previously described the frequency of stomach upset in general terms. No trial abstract we read reports how often it happened, so the honest statement is that it is commonly mentioned and its frequency is unknown.

The anaphylaxis case deserves a careful reading because it shows how to weigh a single report. The authors did not conclude that shilajit caused the reaction. They concluded that it can act as a cofactor, a trigger that adds to other risk factors, in a person at high risk such as someone with mast cell activation syndrome, and they reported the case to alert doctors to ask about complementary medicines when they investigate exercise-induced anaphylaxis. It is a reminder that a substance which is fine for most people can matter a great deal to a person with a particular condition. It is not evidence that shilajit is dangerous for the general population.

The main risk: what is in the jar

Shilajit is defined by where it forms. As we explain in the complete guide, it seeps from rock cliffs at altitude, where the surrounding minerals, water and organic matter contribute to what comes out. A 2020 geological study of Tibetan shilajit found the exudation points on steep slopes of slate and carbonaceous slate at 2,000 to 4,000 metres. The mineral bed can hold metals as well as the calcium and potassium that make shilajit "mineral-rich". Unlike a plant grown in a field, there is no farmer controlling the soil, and no two collection sites are the same.

The evidence on what is actually found comes from four kinds of source, summarised in Table 2 and discussed below.

The first two rows are the direct evidence. The 2021 analysis of Indian and Pakistani shilajit is the study most relevant to products from the Karakoram and Himalayan belt. It used laser-induced breakdown spectroscopy and confirmed its results with ICP-OES/MS and EDX, and reported that both countries' shilajit contained lead, arsenic and mercury above permissible limits in amounts the authors describe as exceeding the standards. The sample counts are not in the abstract, so we cannot say what proportion of shilajit that means, and we would not generalise it to every jar. We can say that raw shilajit from this region is not automatically clean.

The thallium study is worth understanding because thallium is rarely on a supplement's certificate. Thallium is a toxic metal that the authors say bioaccumulates in the kidneys and bones. They tested 13 crude shilajits from five countries and 5 commercial supplements and measured it in both groups, with the highest crude value in an Iranian sample and the highest overall in a supplement. Two of the study's messages are easy to miss. One is that processing does not necessarily remove a metal, since some supplements contained more thallium than the crude shilajit. The other is that the amount in a single tablet was small, up to 0.095 micrograms, and the authors compare it with a maximum dose of 15 micrograms and a normal dietary intake of less than 2 micrograms a day. Figure 1 puts those numbers on one scale.

Read fairly, the thallium chart is reassuring about a single tablet of the products tested and unsettling about what nobody has measured: the cumulative effect of years of daily use, and the thallium content of products that were not in the study. The authors called for standardised testing and safe thallium limits for these products, which do not yet exist.

Why testing matters more than origin or price

Buyers reach for shortcuts: choose a famous mountain, pay more, avoid the raw form. The evidence suggests none of these is reliable. Both Indian and Pakistani shilajit contained metals above permissible limits in the 2021 analysis, so the country of origin did not make one clean. Processing did not reliably help either: in the 2025 study, some supplements contained more thallium than the crude shilajit. And in the independent test of eight commercial products, the range of fulvic acid content and the price per 100 mg varied enormously, which means price and label tell you about marketing, not about purity.

The broader literature on Ayurvedic medicines shows the same pattern. Saper and colleagues bought 230 Ayurvedic products from 25 websites in 2005, analysed the 193 that arrived by x-ray fluorescence, and reported in JAMA in 2008 that 20.7% contained detectable lead, mercury or arsenic. The rate was almost the same in products made in the United States (21.7%) as in India (19.5%), so a Western label did not protect the buyer. Products made by rasa shastra, the traditional practice of deliberately combining herbs with metals and minerals, had a much higher rate (40.6% against 17.1% for the rest). Every product that contained metals exceeded at least one standard for acceptable daily intake. Figure 2 shows the figures. Shilajit is not a rasa shastra product and these were not shilajit specifically, but the study is a good illustration of what happens when supplements are sold without routine testing.

Why these particular metals matter

The metals that come up in shilajit testing are the ones public health agencies have studied most because they cause harm at low exposures and build up over time. Table 5 summarises what the World Health Organization and other authorities say about each. The point of the table is not to alarm but to show why "small amounts" is not automatically the same as "harmless" for this group of substances.

Notice how many of the entries mention the kidneys, and how many mention pregnancy or children. That is the reasoning behind the advice in Table 4 for people with kidney disease and for pregnant women. It is not that shilajit has been shown to harm them, it is that the metals a poorly made product might contain harm exactly those groups most.

Reading the ConsumerLab result carefully

The most reassuring piece of evidence on shilajit contamination is the 2024 ConsumerLab test, and it is worth understanding what it does and does not show. ConsumerLab bought eight products and had them analysed. It reported that lead, cadmium, arsenic and mercury in all eight were below levels of concern when taken as one dose a day, and its summary adds that some products would exceed strict limits on lead if taken more than once a day. It also reported that one product could not be approved for a different reason, a fulvic acid content far higher than its label claimed, which shows that the label of a shilajit product can be wrong in either direction.

Three limits apply. Eight products are a sample, and the brands that ConsumerLab chose to test are ones that sell widely, so the result speaks for well-known products and not for the many small sellers of loose resin. Second, the test was of specific lots at one time; a different batch of the same brand may differ. Third, the "levels of concern" are expressed as amounts per daily dose, so the conclusion depends on taking the labelled serving, and the note about lead at more than one dose a day is a reminder that doubling the dose can move a product from acceptable to not. All of this points to the same practical advice: the reassurance belongs to the tested lots of the tested products, and for anything else you need the seller's own batch report.

How to turn a laboratory number into a daily exposure

Lab reports state metals as a concentration, usually micrograms per gram, which is the same as parts per million. What matters for your body is the amount you swallow a day, and that is the concentration multiplied by the weight of product you take. For example, 0.5 micrograms per gram in a 0.5 gram dose delivers 0.25 micrograms. The same relationship is used by regulators, who set a permitted daily exposure for each metal and work out the allowable concentration by dividing that limit by the daily dose. The smaller the dose, the higher the concentration that can be allowed for the same exposure, and the larger the dose, the lower. Table 3 works the arithmetic for thallium using the reported values and two illustrative cases.

Table 3 makes two points. First, the dose you take matters, but the concentration matters as much: a product ten times more contaminated delivers ten times the metal at the same dose, which is why the certificate matters. Second, the smaller amount in a food-format product such as our bite scales down the exposure from any given concentration, since 50 mg of shilajit carries a tenth of the material that 500 mg does. That is a genuine advantage, but it is not a substitute for a test: we do not know the concentration in our shilajit, and the fifth row assumes a number to show the arithmetic.

The old version of this page carried a table of metal limits in parts per million attributed to the United States Pharmacopeia and to World Health Organization guidance. We could not verify those figures against the source documents, and the USP chapter on elemental contaminants works by daily exposure per dose as described above, not by a single ppm limit, so we have removed the table rather than leave numbers we cannot stand behind.

Who should avoid shilajit

Guidance on who should not take shilajit comes from clinicians and reviewers, not from trials, because trials excluded these groups or did not study them. Table 4 lists the groups that a physician quoted by Cleveland Clinic advises should avoid it, the reasoning, and what we found in the literature. Where our earlier pages listed groups without support, we say so.

We have narrowed the list from the earlier version of this page. It included sickle cell disease, gout and high uric acid, and an "immunostimulatory effect" described as established. We could not find a source for the first two, and the immune claim rests on preliminary research, so we removed those items instead of repeating them. That does not mean they are safe. It means we cannot show that they are dangerous, and the sensible reading of the broader list is that anyone with a medical condition or on regular medication should ask a doctor before using shilajit.

What is known about long-term use

The longest human study we found ran for 48 weeks. Nobody has studied shilajit taken every day for years, so the honest position is that long-term safety is unknown, not that it is proven safe or proven harmful. Two features of shilajit make that gap more important than usual.

The first is accumulation. Some metals, thallium among them, build up in the body's tissues. The authors of the thallium study say it bioaccumulates in the kidneys and bones, and that long-term consumption of supplements could lead to accumulation. A single tablet of the products they tested added 0.095 micrograms, about 5% of the upper bound of normal dietary intake and 0.6% of the reference maximum. Small daily amounts over years are what accumulate. We are not saying this is happening. We are saying that nobody has measured it, which is a reason for caution before making shilajit a lifelong habit.

The second is that the popular safeguard of "cycling", taking a week off every two months, does little for this problem. If a product contains a metal, stopping for one week in eight cuts your exposure by one eighth, which is not a meaningful protection, and no study has tested whether cycling helps in any other way. A better safeguard is a tested product, a modest dose, and periodic review with a doctor of whether you still need it. If you use shilajit long term, tell your doctor and ask whether any monitoring is appropriate for your circumstances. There is no established monitoring protocol for shilajit users, and we would not invent one.

If you think you have had a reaction

Stop taking it. Symptoms that could signal an allergic reaction, such as hives, swelling of the face or throat, wheezing or difficulty breathing, dizziness or fainting, need emergency medical care immediately. For milder problems such as stomach upset or headache, stopping is usually enough, and it is worth telling your doctor if symptoms persist or if you have other conditions. Keep the packaging and note the batch number, as that helps if the product needs to be investigated. In the United States, side effects from supplements can be reported to the FDA's MedWatch system, and other countries have similar reporting systems run by their medicines regulators. Reports are how regulators and researchers learn about rare problems that trials are too small to detect.

Where our Shilajit Choco Bites stand on safety

Our Shilajit Choco Bites contain approximately 0.05 g (50 mg) of shilajit each, which is a tenth of the most common trial dose and a much smaller exposure to anything in the shilajit than a resin or capsule serving. The product page also states that they are recommended for adults aged 40 and over and are not suitable for people with hemochromatosis.

What we cannot yet tell you is what is in our shilajit. We have not published a batch-matched heavy metal report for it on this site. Earlier pages said the shilajit was tested, while our previous safety page said documentation was still being finalised and would be linked once available. The unsupported wording is gone, and until a batch report exists you should treat the contamination question as open for our product, as you should for any product that cannot show one.

There is one more point specific to a chocolate product. The chocolate base is a possible source of lead and cadmium in its own right. Testing by Consumer Reports of 28 dark chocolate bars, which we describe in our chocolate guide, found lead alone in 10 of them, cadmium alone in 8, both in 5, and neither in 5. So the metals question for a chocolate-based shilajit product covers the cocoa as well as the shilajit, and a full test would need to cover the finished product.

Raw resin, purified extract and "wild" shilajit

A common marketing idea is that the rawer and wilder the shilajit, the better. The safety evidence points the other way. Cleveland Clinic, citing a 2024 research review, states that raw shilajit often contains aluminium, arsenic, cadmium, chromium, mercury, thallium, lead and fungus. Raw material is what comes out of the rock, along with whatever else was in the crack. That is why traditional practice, and every clinical trial we found, used shilajit that had been purified or processed in some way, and why the trials describe their material as purified, processed or standardised, not "raw".

The reverse is not automatically true either. Purified does not mean clean, as the thallium study shows: some finished supplements contained more thallium than the crude shilajit measured in the same paper. Purification can remove sand, debris and some contaminants, but it cannot be assumed to remove all metals, and a supplement can also add fillers, excipients or other raw materials that bring their own residues. What separates a safe product from an unsafe one is neither the word "raw" nor the word "purified". It is a laboratory result for the actual batch.

The practical consequence is a warning about one particular kind of purchase: loose resin from an informal seller, a market stall, or an unverified overseas listing, with no laboratory paperwork and no named lot. Such a product may be excellent, and you have no way to know. Since the metals discussed above cannot be seen, smelled or tasted, the appearance of authenticity, a dark colour, a tarry texture or a mineral smell, tells you nothing about what it contains. If the seller cannot show a report, the safe assumption is that it is untested.

What we still do not know

A safety guide that ends with reassurance would be misleading, because most of the important safety questions about shilajit are simply unanswered. Here is what we could not find.

• Long-term safety. No study beyond 48 weeks, and none of daily use for years.
• Safety in pregnancy, breastfeeding and childhood. No studies. Advice to avoid it rests on the absence of data and on the effects of possible contaminants.
• Interactions with medicines. No published interaction studies with diabetes, thyroid, blood pressure, blood-thinning or immune-suppressing medicines, so the warnings are precautionary.
• How often side effects occur. The trial abstracts we read do not give frequencies, so we cannot say how common stomach upset or headache is.
• Safe limits for thallium. The authors of the 2025 study call for them, which implies they are not established for supplements.
• How representative testing is. The published analyses cover a few dozen samples from a handful of countries. Nobody has tested a random sample of what is on sale.
• Whether purification removes metals reliably. Some supplements had more thallium than the crude material, so purification is not a guarantee.

Better evidence would look like a large, independent, placebo-controlled trial that records adverse events systematically and measures blood and urine metal levels before and after, plus routine batch testing published by sellers. Until that exists, your protection is a tested product, a moderate dose and a doctor who knows what you are taking.

What we corrected from our earlier safety pages

Because this page replaces several older ones, here is what changed. We removed the table of ppm limits attributed to the USP and WHO, which we could not verify. We removed the statement that hormonal side effects in women are "more strongly associated" with adulterated products. We removed sickle cell disease, gout and high uric acid from the list of groups to avoid because we found no source, and we widened the list to include the groups named in current clinical guidance. We removed the claim that no dependency or withdrawal effects have been documented, since nobody has studied that question. We added the 2025 thallium study, the 2021 analysis of Indian and Pakistani shilajit, and the case reports. And we corrected our description of our own product: we have not published a batch-matched heavy metal report for its shilajit, whatever earlier pages implied.

A checklist before you take any shilajit

1. Do you have a medical condition, take any medicine, or are you pregnant, breastfeeding or trying to conceive? If so, ask a doctor first.
2. Can the seller show a laboratory report for this batch, naming the lab and method, with results for lead, arsenic, cadmium, mercury and ideally thallium?
3. Does the report's batch number match the one on your product?
4. Is the dose stated in milligrams of shilajit, and are you staying within the range that has been studied, 200 mg to 1,000 mg a day?
5. Have you decided how long you will try it and how you will judge whether it did anything?
6. Do you know what you will do if you have a reaction?
7. Are you sure you are not buying it to replace something that has better evidence, such as sleep, exercise, diet or a doctor's advice?

Frequently asked questions

Is shilajit safe?

In small trials of purified preparations at 200 mg to 1,000 mg a day for up to 48 weeks, no serious problems were reported. But those trials were small and short, several abstracts say nothing about safety, and the main risk, contamination with heavy metals, depends on the product, not on shilajit itself.

Does shilajit contain heavy metals?

It can. A 2021 analysis found lead, arsenic and mercury above permissible limits in some Indian and Pakistani shilajit, and a 2025 study measured thallium in crude shilajit and supplements. Independent testing of eight commercial products found lead, cadmium, arsenic and mercury below levels of concern at one dose a day.

Who should not take shilajit?

Physician guidance advises avoiding it in pregnancy, breastfeeding, when trying to conceive, in children, and with hemochromatosis, autoimmune conditions, diabetes, heart or blood pressure problems, blood thinners, and liver or kidney disease.

Can I take shilajit every day for years?

Nobody knows. The longest human study lasted 48 weeks. Because metals can accumulate, a tested product and periodic review with a doctor are sensible.

Are your Choco Bites tested?

We have not published a batch-matched heavy metal report for the shilajit in them. We say so plainly and suggest you weigh that.

This article is for general information and is not medical advice. It has not been evaluated by the FDA, Health Canada, the MHRA or any other regulator, and shilajit or any product containing it is not intended to diagnose, treat, cure or prevent any disease. If you are pregnant, breastfeeding, managing a health condition or taking medication, speak to a qualified healthcare provider before using it.

Sources

1. Cleveland Clinic. Shilajit: benefits, side effects and uses (health.clevelandclinic.org/shilajit-benefits).
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5. ConsumerLab.com. Shilajit supplements found to contain high amounts of fulvic acid (26 September 2024), and review summary.
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10. Das A, El Masry MS, Gnyawali SC, et al. Skin transcriptome of middle-aged women supplemented with natural herbo-mineral Shilajit. J Am Coll Nutr 2019;38(6):526-36. PMID 31161927.
11. Sadeghi SMH, et al. Efficacy of Shilajit in tibia fracture repair. J Altern Complement Med 2020;26(6):521-8. PMID 32310691.
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13. Consumer Reports testing of dark chocolate bars for lead and cadmium, as summarised in our chocolate guide.
14. World Health Organization. Fact sheets: Lead poisoning and health; Arsenic; Mercury and health.
15. ATSDR and UK Health Security Agency toxicological overviews of cadmium (kidney and bone effects of chronic exposure).