Shilajit: Fulvic Acid, Mineral Composition, and the State of the Research

Few substances in traditional medicine sit as awkwardly at the intersection of geology, microbiology, and folklore as shilajit. It is not a plant, not a mineral in the strict sense, and not quite a fossil. It is a viscous, blackish-brown to dark-amber resin that oozes out of rock fissures in high-altitude mountain ranges during the warm months, and it has been used in Ayurveda for at least a thousand years under names like shilajit, mumijo, mumie, salajit, and moomiyo.

Modern interest is driven by a much narrower claim: that the resin's combination of fulvic acid, humic substances, dibenzo-alpha-pyrones (DBPs), and a long list of trace minerals delivers measurable effects on mitochondrial bioenergetics, testosterone, sperm parameters, and possibly cognition and longevity. The marketing has run far ahead of the evidence. This article walks through what shilajit is, what is actually in it, what the published trials show, where the contamination risks sit, and how to read a quality grade.

What shilajit actually is

The most widely cited origin model — proposed by Ghosal and colleagues in the 1990s and elaborated by Carrasco-Gallardo and Aguirre — is that shilajit forms over centuries from the slow microbial and oxidative decomposition of specific plant material, including Euphorbia royleana, Trifolium repens, and various mosses and lichens, trapped between rock layers at altitude. Heat, pressure, and microbial activity convert this material into a humified resin that periodically liquefies and seeps out of cliff faces during summer.

Geographic source matters more than most supplement labels admit. Composition differs measurably between:

• Himalayan shilajit — Nepal, India, Bhutan, Tibet. The most heavily studied source and the one referenced in most Ayurvedic texts.
• Altai shilajit (mumijo) — Russia, Mongolia, Kazakhstan. Often higher in humic substances and historically used in Soviet-era sports medicine.
• Caucasus shilajit — Georgia, Azerbaijan, parts of Iran.
• Andean shilajit — Peru, Chile. A more recent commercial source, with limited published characterisation.

Two products labelled "shilajit" from different ranges are not chemically interchangeable. Independent assays have shown several-fold differences in fulvic acid content and very different trace mineral profiles between Himalayan and Altai sources.

What is actually in it

The chemistry is genuinely interesting, but it is also where the marketing overstates the evidence. The major components — characterised in detail in Carrasco-Gallardo et al. 2012 Int J Alzheimers Dis — shilajit composition — are:

• Fulvic acid — the most quoted bioactive. Fulvic acid is a low-molecular-weight humic substance with chelating and antioxidant properties in vitro. Quality shilajit assays typically report 15 to 20 percent fulvic acid by mass, though some commercial products report figures that are not chemically plausible.
• Humic acid — higher-molecular-weight humic substance with weaker absorption and less direct bioactivity claim.
• Dibenzo-alpha-pyrones (DBPs) and DBP-chromoproteins — a class of small phenolic compounds proposed as the actual mitochondrial-active fraction. Ghosal's group argued DBPs act as electron carriers that can support coenzyme Q10 (CoQ10) at the inner mitochondrial membrane.
• 80-plus trace minerals — iron, magnesium, calcium, potassium, zinc, copper, selenium, and many others, in highly variable ratios depending on source rock.
• Small amounts of amino acids, phospholipids, and resins.

The "80-plus minerals" claim is real but uninformative. Soil and seawater also contain 80-plus elements; what matters is the concentration of each, the chemical form, and whether bioavailability is meaningful at the daily dose actually taken (usually 300 to 500 mg of purified resin).

The heavy metal contamination problem

This is the single most important practical issue with shilajit, and it does not get enough airtime in consumer marketing.

Because raw shilajit is, chemically speaking, a concentrated geological extract, it accumulates whatever heavy metals exist in the surrounding rock. Multiple independent surveys of raw, unprocessed shilajit sold in South Asian markets have detected lead, arsenic, and mercury at concentrations well above the limits set for dietary supplements in the EU, Australia, and the United States. Some samples have exceeded permissible daily intakes for lead by an order of magnitude.

Traditional Ayurvedic shodhana (purification) — repeated extraction in water or Triphala decoction, filtration, and slow concentration — was developed in part to reduce mineral and metal load. Modern industrial purification adds steps like reverse osmosis, activated carbon filtration, and standardisation to fulvic acid or DBP content. The branded ingredient most often cited in clinical trials, PrimaVie shilajit, is purified and standardised by Natreon and reports third-party heavy metal testing within US Pharmacopeia limits.

Stohs 2014 — shilajit safety review concluded that purified, standardised shilajit at typical supplemental doses appears safe in short-term trials, but explicitly warned that raw resin from unregulated sources cannot be assumed safe.

Practical implication: if a shilajit product does not publish a current certificate of analysis showing lead, arsenic, mercury, and cadmium within accepted limits (typically below 0.5 ppm lead, below 1 ppm arsenic, below 0.1 ppm mercury), treat it as unknown-quality.

The mitochondrial bioenergetics claim

The most-quoted mechanistic story for shilajit comes from animal work by Bhattacharyya, Ghosal, and colleagues. In rodent muscle preparations, shilajit (and isolated DBPs) appeared to support ATP production under conditions of fatigue and oxidative stress, and to interact with the CoQ10 cycle at the inner mitochondrial membrane. The proposed mechanism is that DBPs can shuttle electrons and stabilise reduced ubiquinol, slowing the recycling demand on CoQ10 itself.

That mechanism is biologically reasonable, but it has been demonstrated mostly in isolated mitochondria and animal models. Human studies that directly measure mitochondrial respiration after shilajit are rare and small. For broader context on why mitochondrial energy metrics are so hard to translate from rodents to humans, see mitochondria and cognitive performance.

The CoQ10 synergy claim is the most plausible single mechanism but should be read as preclinical. If the underlying interest is mitochondrial CoQ10 status, the form and absorption of CoQ10 itself matter far more than co-administration of shilajit — covered in ubiquinol vs ubiquinone bioavailability.

What the human trials actually show

The clinical evidence base for shilajit is small, mostly conducted on the PrimaVie-standardised ingredient, and weighted toward male reproductive and performance endpoints.

Testosterone and the Pandit 2016 trial

The most-cited human trial is Pandit et al. 2016 Andrologia — shilajit testosterone trial. It was a 90-day, randomised, placebo-controlled study in 75 healthy men aged 45 to 55. The shilajit arm took 250 mg of purified PrimaVie shilajit twice daily.

Outcomes reported: a statistically significant rise in total testosterone, free testosterone, and dehydroepiandrosterone sulphate (DHEAS) versus placebo, with no obvious safety signal. Effect sizes were modest, and the study population was a narrow band of middle-aged healthy men, not hypogonadal patients and not athletes.

Limitations matter. The trial was small, manufacturer-funded, and has not been independently replicated in a comparably sized cohort. It does not justify claims of treating clinical hypogonadism. It is a hypothesis-supporting trial, not a confirmatory one.

Spermatogenesis

A separate 90-day open-label trial in 60 oligospermic men reported improvements in sperm concentration and motility with 100 mg of purified shilajit twice daily. Open-label design and no placebo arm sharply limit the conclusions, but the direction of effect is at least consistent with the testosterone trial.

Exercise performance

A handful of small RCTs in resistance-trained males have reported improved muscle strength retention and supranormal hydroxyproline excretion (a connective-tissue turnover marker) at 500 mg/day PrimaVie. Sample sizes are typically under 70. Compared with the deeper RCT base for compounds like ashwagandha or cordyceps, shilajit's performance evidence is genuinely thin.

Cognition and longevity

This is where the marketing-to-evidence gap is widest. There are interesting preclinical lines — fulvic acid disaggregating tau fibrils in vitro, animal models of Alzheimer-like pathology — but no adequately powered human trial has shown cognitive benefit. Longevity claims have no human outcome data. They are extrapolated from animal antioxidant assays and from the broader literature on NAD+ and cellular energetics — a more rigorously studied space covered in NAD and cellular longevity.

The iron content controversy

Several independent assays have found that shilajit can contain substantial elemental iron — sometimes 4 to 20 mg per gram of resin, depending on source. At a typical 500 mg daily dose, that is a meaningful iron contribution, especially in formulations that do not disclose elemental mineral content.

For most adults this is unremarkable. For two groups it is potentially serious:

• People with hereditary haemochromatosis (HFE gene variants), who already absorb iron at abnormally high rates and are advised to avoid iron-containing supplements unless prescribed.
• Adult men and postmenopausal women with elevated ferritin for any other reason, in whom additional iron is unwanted.

This is a case where a "trace minerals" label is not adequate disclosure. A reasonable shilajit certificate of analysis should report total iron content per dose.

Quality grading and what to actually look for

Shilajit is sold in several forms, and the differences are not cosmetic.

• Raw resin — direct from rock collection, minimal processing. Highest contamination risk; unsuitable for routine consumption unless purified.
• Purified resin (shilajit shodhita) — water-extracted, filtered, concentrated. Standard high-quality product when sourced from a reputable manufacturer.
• Standardised extract (e.g. PrimaVie) — purified resin standardised to a stated fulvic acid percentage and DBP content, with documented heavy metal testing. This is what most of the clinical trials used.
• Shilajit powders and capsules — convenience format. Worth checking whether the powder is purified resin dried onto a carrier or a much weaker shilajit-bearing soil extract.

Reasonable quality checks before buying:

1. Current third-party certificate of analysis for lead, arsenic, mercury, cadmium.
2. Stated fulvic acid percentage (commonly 15 to 20 percent in genuine purified resin).
3. Geographic source disclosed (Himalayan, Altai, etc.).
4. Form clearly stated (raw, purified, standardised extract).
5. Iron content disclosed per serving.

Safety, interactions, and who should avoid it

Short-term human trials of purified shilajit at 250 to 500 mg/day have not reported significant adverse events. Theoretical and reported issues to consider:

• Heavy metal exposure from unpurified product — the dominant safety concern.
• Iron load for people with haemochromatosis or unexplained high ferritin.
• Possible additive effects with hypoglycaemic and antihypertensive medications, based on animal data; clinically unverified but worth flagging to a prescriber.
• Pregnancy and lactation — insufficient data; conventionally avoided.
• Autoimmune conditions — fulvic acid's immunomodulatory effects are mostly in vitro; insufficient human data to guide use.

Shilajit is not a stimulant in the caffeine sense and does not produce the acute energy effect that some marketing implies. Compared with the better-characterised adaptogen and hormonal-modulator literature on maca and ashwagandha, shilajit's clinical positioning is less defined.

Honest summary

Stripped of the marketing, shilajit is a chemically interesting humified resin with a small, mostly manufacturer-sponsored human evidence base in middle-aged male testosterone, sperm parameters, and short-duration exercise outcomes, plus a much larger preclinical literature on mitochondrial bioenergetics and CoQ10 interaction. The single strongest practical issue is not efficacy but contamination: raw shilajit from unregulated sources can carry heavy metals at problematic concentrations, and the consumer's most useful tool is a current certificate of analysis from a purified or standardised product.

The cognitive and longevity claims are not supported by adequate human trials. The performance and testosterone claims are supported by small RCTs that justify further investigation but not strong individual recommendations.

Key takeaways

• Shilajit is a humified mineral resin containing fulvic acid, humic acid, dibenzo-alpha-pyrones (DBPs), and 80-plus trace minerals; composition varies meaningfully by geographic source.
• The major safety concern is heavy metal contamination (lead, arsenic, mercury) in raw resin. Purified, standardised products with third-party COAs are the only reasonable consumer choice.
• The strongest human trial is Pandit 2016 (n = 75 healthy men, 90 days, PrimaVie 500 mg/day) showing modest testosterone rise; it has not been independently replicated.
• Mitochondrial and CoQ10 mechanisms are biologically plausible but mostly preclinical in humans.
• Iron content can be substantial and is a real consideration for people with haemochromatosis or elevated ferritin.
• Cognitive and longevity claims outrun the human evidence; treat them as hypotheses, not findings.