What 'Third-Party Tested' Really Means, and Why Most Shilajit Brands Skip It

Quick answer: Third-party tested means an independent lab with no financial stake in the result ran the tests and published a certificate of analysis showing what is actually in the product. For shilajit this matters more than for most supplements. Shilajit is a mineral resin that absorbs elements from mountain geology over centuries. The same process that deposits 80-plus trace minerals and high-density fulvic acid can also deposit heavy metals. A full, genuine COA for shilajit shows fulvic acid percentage, heavy metal levels for arsenic, mercury, lead, and cadmium, mycotoxin screening, and Prop 65 compliance. Most brands do not publish the complete version because it costs real money, and it tells you exactly what is and is not in the product.

Why shilajit needs independent testing more than most supplements

Shilajit forms over thousands of years as plant matter and mineral deposits are compressed in high-altitude rock. That geological process is the source of its 80-plus trace minerals and the fulvic acid that gives it most of its recognized value.

The same geological exposure that deposits those minerals can also deposit arsenic, mercury, lead, and cadmium. Whether those contaminants are present in a finished tablet at a safe level depends on where the shilajit was sourced and how thoroughly it was purified.

A 2024 review documented that shilajit can carry trace heavy metals from its source geology, and it also found that the humic substances in shilajit actively bind and help neutralize approximately 12 of those metals (https://pubmed.ncbi.nlm.nih.gov/38393486/). Well-purified, high-fulvic-acid shilajit is actually more capable of managing mineral load than raw, low-grade product. But binding is not the same as eliminating. The only way to know the levels in a finished product is to measure them.

A 2021 ICP-MS analysis of commercial shilajit products confirmed that thoroughly tested samples met FDA limits for arsenic, mercury, lead, and cadmium (https://pubmed.ncbi.nlm.nih.gov/34800280/). The key phrase there is thoroughly tested. Products that were not submitted to the same analytical standard were not on the same footing.

There is also a geography factor. A 2025 study found that thallium levels in shilajit vary considerably by source region. Iranian shilajit averaged 0.226 micrograms per gram while Indian shilajit averaged 0.007. Shilajit from the Altai mountains was not flagged as a concern in that analysis (https://pmc.ncbi.nlm.nih.gov/articles/PMC11743217/). Source transparency is part of what a real test supports.

What a complete COA for shilajit should show

A certificate of analysis is only useful if it covers the right measurements. For shilajit, that means at minimum 4 things.

Fulvic acid percentage. This is the primary active compound. The human clinical trials on shilajit used extracts standardized to at least 50% fulvic acid. A brand that cannot tell you the exact percentage with a lab result does not know what is in the product.

Heavy metal panel. Arsenic, mercury, lead, and cadmium at minimum, with the measured values compared against FDA and Prop 65 limits. Some panels also screen for thallium given the geographic variation noted above.

Mycotoxin screening. Shilajit is an organic resin. If the purification step is incomplete, mold metabolites can survive processing. A genuine COA screens for these.

Batch identification. A real COA carries a specific batch number. That number allows any result to be traced back to a production run. A COA without a batch number is a reference document, not a verification of what you are holding in your hand.

What Prop 65 compliance actually means

California's Proposition 65 is a right-to-know law that requires companies to warn consumers if a product contains listed chemicals above certain thresholds, including arsenic, mercury, lead, and cadmium. Meeting Prop 65 compliance means testing confirmed the levels are below those thresholds.

The Prop 65 limits are more conservative than basic FDA requirements, which is why they serve as a meaningful benchmark. Passing them means the product was tested against a tighter standard than the federal minimum.

A brand that claims Prop 65 compliance should be able to point you to the specific COA values that support that claim. The statement alone, without the numbers behind it, is just a marketing line.

Why most brands publish an incomplete version

Lab testing costs money and time. A full panel from an accredited, independent laboratory runs several hundred to several thousand dollars per batch depending on what is screened.

More importantly, if a brand has a product with a low fulvic acid content, an elevated heavy metal result, or a failed mycotoxin screen, a complete third-party test makes that visible. An incomplete test or an in-house test does not.

There is no federal regulation requiring supplement brands to publish a COA at all. Many run only basic microbiological panels or select tests that return favorable results. Some publish documents from labs they own or partly fund, which is testing but not genuinely independent.

True third-party testing means the lab has no financial relationship with the brand and no stake in the outcome of the result.

The fulvic acid percentage tells you whether the product is real

Heavy metal testing tells you whether the product is safe. The fulvic acid percentage tells you whether the product is effective.

The research behind shilajit's recognized properties was done on standardized extracts. The 2022 Pingali clinical trial at Nizam's Institute of Medical Sciences, the first randomized, double-blind, placebo-controlled study to show a dietary shilajit ingredient improving bone density in postmenopausal women, used a shilajit extract standardized to at least 50% fulvic acid taken once daily after food (https://pubmed.ncbi.nlm.nih.gov/35933897/).

A tablet at 10% or 15% fulvic acid is not the same formulation. A claim that it produces the same results is not supported by the research, because the research was done on a specific preparation.

When a brand says their product works like the clinical studies show, but cannot tell you the fulvic acid percentage with a lab result, those 2 things do not fit together.

What to look for when evaluating a brand

Ask whether the COA is from an accredited, independent lab. ISO 17025 is the international standard for testing laboratories. NSF, USP, and state-licensed equivalents are meaningful too.

Ask whether the results are batch-specific or a single historical reference test.

Ask whether the panel covers fulvic acid percentage, heavy metals, and mycotoxins together, or only some of them.

Ask whether the brand will share the specific values rather than just the compliance status.

A brand that answers these questions clearly and shows you the numbers is doing something that takes real resources. One that redirects to general purity language without specific data is telling you something too.

Our testing

Optimum shilajit comes from the Altai mountains, cold pressed and purified. Every batch is third-party tested at an independent, accredited laboratory for heavy metals, mycotoxins, and fulvic acid content, and is Prop 65 compliant in California. We are a small, family-owned company out of Florida. If you want to see the COA for your specific batch, the team is reachable directly.

Across every human clinical study ever done on shilajit, zero serious adverse events have been reported.

If you want to start with a product you can verify, you can find Optimum Shilajit here: https://www.liveoptimum.co/products/optimum-shilajit

Frequently asked questions

What does "third-party tested" actually mean for a supplement?

It means an independent lab with no financial relationship to the brand ran the analysis and issued the certificate. Tests run by a lab the brand owns or funds are not genuinely third-party, even if the results look official.

What should a shilajit COA include?

At minimum, fulvic acid percentage (50% or higher is the research standard), heavy metal levels for arsenic, mercury, lead, and cadmium compared against FDA and Prop 65 limits, mycotoxin screening, and a batch number to trace the specific production run.

Does shilajit naturally contain heavy metals?

Trace amounts can be present from the geological source. A 2024 review found the humic substances in shilajit actively bind approximately 12 heavy metals. Binding is not the same as elimination, though. A purification step plus independent testing is what brings levels below safe thresholds.

What is Prop 65, and why does it matter for supplements?

California's Proposition 65 requires disclosure when a product contains chemicals above specific thresholds, including several heavy metals. Meeting Prop 65 means testing confirmed the levels are below those conservative limits, a standard more stringent than basic FDA requirements.

Why does the fulvic acid percentage matter?

The human clinical trials on shilajit used extracts standardized to at least 50% fulvic acid. A product with a much lower percentage is a different formulation from the one studied, and comparing it to the clinical research is not accurate.

References

1. Heavy metals in shilajit and humic binding capacity (review 2024). https://pubmed.ncbi.nlm.nih.gov/38393486/
2. ICP-MS quantification of commercial shilajit products 2021. https://pubmed.ncbi.nlm.nih.gov/34800280/
3. Thallium content in shilajit supplements by source geography 2025. https://pmc.ncbi.nlm.nih.gov/articles/PMC11743217/
4. Pingali U, Nutalapati C. Shilajit extract reduces oxidative stress, inflammation, and bone loss to dose-dependently preserve bone mineral density in postmenopausal women with osteopenia: A randomized, double-blind, placebo-controlled trial. Phytomedicine. 2022;105:154334. https://pubmed.ncbi.nlm.nih.gov/35933897/