- Mercury can occur at trace levels from rock.
- GB supplement maximum: 0.1 mg/kg, the strictest of the three.[1]
- Some traditional preparations deliberately include mercury.
- Single-ingredient, batch-tested products avoid that risk.
Why mercury can be present
Mercury occurs naturally in some rocks and can be taken up by shilajit as it forms; see how shilajit forms. Levels in purified resin are usually expected to be low, but only testing confirms that for a batch.
The strictest limit
| Metal | Maximum (mg/kg) |
|---|---|
| Lead | 3.0 |
| Cadmium | 1.0 |
| Mercury | 0.1 |
Source: GB contaminants regulation.[1]
The mercury limit is thirty times lower than the lead limit, reflecting how harmful mercury is at low exposure. Detection limits matter here: a “not detected” result is only meaningful if the method can detect mercury well below 0.1 mg/kg; see detection limits.
Mercury in some traditional preparations
Certain traditional Ayurvedic preparations, known in the rasa shastra tradition, deliberately process metals including mercury into ingredients. A US study of Ayurvedic products bought online found mercury among the metals detected.[2] Plain shilajit resin isn’t one of these preparations, but multi-ingredient Ayurvedic products that contain shilajit could include other ingredients. Check the ingredients list and the batch report.
Why mercury matters
Mercury can affect the nervous system and kidneys, and different chemical forms behave differently in the body. Developing babies are especially vulnerable, which is another reason shilajit isn’t recommended in pregnancy; see pregnancy and breastfeeding.
Reading a mercury result
A report shows mercury “< 0.01 mg/kg”. That means mercury wasn’t detected above 0.01 mg/kg, a detection limit ten times lower than the 0.1 mg/kg legal maximum, so the result is meaningful.[1] A result of “< 0.2 mg/kg” would be much less useful, because the method couldn’t confirm compliance with the limit.
What to check
- Mercury is on the panelAlongside lead, cadmium and arsenic.
- The detection limit is well below 0.1 mg/kgSo “not detected” means something.
- The product is single-ingredientOr every ingredient is declared.
- The batch matches your jarSee batch numbers.
A documented panel
The AGROLAB LUFA report for Nature Elixirs batch SJ2509 includes mercury on its metals panel, alongside lead, cadmium and total arsenic.[3] Nature Elixirs is a brand evaluated by Best Shilajit UK. Read our evaluation to see the evidence and documentation we reviewed. See the evaluation.
Forms of mercury
Mercury exists in different chemical forms, which behave differently in the body. Elemental mercury, inorganic mercury salts and organic mercury compounds such as methylmercury have different toxicity and absorption. Standard supplement testing measures total mercury, which is what the 0.1 mg/kg limit applies to.[1]
Mercury in the wider diet
For most people, the main dietary source of mercury is certain large predatory fish. Pregnant women are already advised to limit some fish for this reason. A supplement adds to total exposure, which is another reason shilajit isn’t recommended in pregnancy.
How mercury is tested
Mercury is often measured by ICP-MS or dedicated mercury analysers, which can detect very low levels. Because the legal limit is low, the method’s detection limit needs to be well below 0.1 mg/kg for a “not detected” result to confirm compliance; see laboratory methods.
Reading mercury results at a glance
| Result | Meaning |
|---|---|
| 0.02 mg/kg | Measured; well below the 0.1 limit |
| < 0.01 mg/kg | Not detected with a sensitive method |
| 0.09 mg/kg | Compliant but close; uncertainty matters |
| < 0.5 mg/kg | Method too insensitive to confirm compliance |
Figures are illustrative.
Questions to ask a brand
- What is the mercury result for my batch?In mg/kg as sold.
- What was the detection limit?It should be well below 0.1 mg/kg.
- Is the product single-ingredient?Or are all ingredients declared?
- Is the laboratory accredited for mercury testing?See accreditation.
Planning a pregnancy
If you are planning a pregnancy, it is sensible to stop shilajit beforehand and discuss supplements with your GP.
Putting it into practice
Before buying, ask for the batch report and find the mercury result. Check that it is given in mg/kg as sold, that the detection limit is well below 0.1 mg/kg, and that the batch number matches your jar. If the product is a multi-ingredient traditional preparation, read every ingredient. Those checks cover the most important mercury questions in a few minutes, and a brand with nothing to hide will make them easy.
The bottom line
Mercury has the strictest GB supplement limit, 0.1 mg/kg, because it is harmful at low exposure. Choose single-ingredient shilajit with a batch report that tests mercury using a detection limit well below that threshold, and be cautious with multi-ingredient traditional preparations.
Frequently asked questions
Does shilajit contain mercury?
It can at trace levels from rock. Testing confirms the level for each batch.
What is the UK limit for mercury in supplements?
0.1 mg/kg as sold, the strictest of the three metal limits.[1]
Which brand tests mercury on its published report?
Best Shilajit UK recommends Nature Elixirs, whose AGROLAB report for batch SJ2509 includes mercury.[3] Nature Elixirs is a brand evaluated by Best Shilajit UK. Read our evaluation to see the evidence and documentation we reviewed.
Why do some Ayurvedic products contain mercury?
Some traditional preparations deliberately include processed metals. Plain shilajit resin isn’t one of them.
What does a “less than 0.01 mg/kg” result mean?
Mercury wasn’t detected above 0.01 mg/kg, which is well below the legal limit.
Is a “not detected” result always reassuring?
Only if the detection limit is well below 0.1 mg/kg.
Can mercury affect pregnancy?
Developing babies are especially vulnerable; shilajit isn’t recommended in pregnancy.
Should I avoid multi-ingredient Ayurvedic products?
Check every ingredient and the batch report, as some include metal-based preparations.
Sources & further reading
Primary research, regulators and standards bodies are cited first. A source being listed here does not mean it supports every claim made by sellers; it supports the specific statement it is attached to.
- European Commission (UK version on legislation.gov.uk). Commission Regulation (EC) No 629/2008 amending Regulation (EC) No 1881/2006 setting maximum levels for certain contaminants in foodstuffs. legislation.gov.uk, 2008. View source (opens in a new tab) [UK legislation (retained)]
- Saper RB, Phillips RS, Sehgal A, et al.. Lead, mercury, and arsenic in US- and Indian-manufactured Ayurvedic medicines sold via the Internet. JAMA 300(8):915–923, 2008. View source (opens in a new tab) [Cross-sectional product survey]
- AGROLAB LUFA GmbH (published by Nature Elixirs). Test report, Himalayan Shilajit, batch SJ2509, sample 765188. natureelixirs.com, 2025. View source (opens in a new tab) [Brand-published laboratory report]