Shilajit: resin, labels and the research

Few supplements arrive looking like a tub of tar with a pedigree, and shilajit does. It's dark, sticky, smells somewhere between soil and old leather, and comes with a story involving Himalayan cliffs. Before you pick up a spoon, it's worth knowing what shilajit is, what the research has measured, and what's worth a look on the label besides the mountain on the front.

Here's the plot in one breath. Shilajit is a dark, humic-rich exudate collected from mountain rock, sold as raw resin, powder or purified extract. The human evidence is a few small trials, mostly of purified extracts and some funded by the extract's maker, looking at testosterone, sperm count, muscle fatigue and bone density. No human trial has tested whether it changes lifespan or ageing. Lab analyses of samples have found heavy metals, mostly low but not always. And on 8 October 2026 the Dutch herbal-preparations decree did not name it.

What is actually in the tub?

Shilajit (also written mumijo, mumie or asphaltum punjabianum) is a hard thing to define, and that's the first surprise. The European Commission's novel food consultation describes it as "a complex product of both organic and mineral origin", "not uniquely defined either in origin (animal, vegetable or mineral) or in composition", and characterised by humic and fulvic acids, dibenzo-α-pyrones and a range of minerals (EU novel food status consultation, mumijo).

Scientists are still working out the basics. A 2025 review found that its chemical composition "is not known with certainty", that more than 80% of its weight is humic substances and roughly a fifth is calcium, potassium and magnesium, and that people still disagree about whether it forms from decayed plants, animal matter or mineral seepage (Kamgar et al. 2025, Crit Rev Anal Chem). A 2026 analysis of eleven samples from Iran, India, Nepal, Russia and Kyrgyzstan quantified plant-derived phenolic acids across them, which supports the plant-origin idea, and showed large differences between regions (Kamgar et al. 2026, Sci Rep).

Fulvic acid is the name you'll see most. It's one fraction of the humic material, a mixture of organic acids rather than a single molecule. Products often quote a fulvic acid percentage, but we found no agreed standard for what a label's percentage should mean. The same goes for popular figures such as a fixed fulvic acid share or "80+ minerals": we found no source that backs them as facts about shilajit in general.

What has anyone measured in people?

Shilajit claims rest on three different kinds of evidence, and they shouldn't be blended: lab and animal work, a small number of human trials, and chemistry.

Lab and animal studies cover things like tau protein clumping in neurons or antioxidant behaviour. One example is a 2023 cell-culture study of fractions of Andean shilajit, which reported lower tau aggregation in those cells (Andrade et al. 2023, Pharmaceuticals). That's an interesting lead for researchers, and it doesn't tell us what happens in a person drinking it in warm water. Talk of mitochondria, brain health and "longevity" belongs in this category for now.

The human trials are small. The table lists what each one measured, which is not the same as what it proved.

• Study: Pandit et al. 2016, Andrologia; Who took part: Healthy men aged 45 to 55, randomised, double-blind, placebo-controlled; Preparation and dose: Purified shilajit, 250 mg twice daily; Length: 90 days; What was reported: Total testosterone, free testosterone and DHEAS rose more than with placebo; LH and FSH were maintained; Funding and limits: The abstract gives neither participant numbers nor funding
• Study: Biswas et al. 2010, Andrologia; Who took part: 60 infertile men screened; 35 with low sperm counts enrolled; 28 finished; Preparation and dose: Processed shilajit, 100 mg twice daily; Length: 90 days; What was reported: Total sperm count +61.4%, motility and testosterone (+23.5%) up compared with baseline; Funding and limits: No placebo group, so changes may not be due to shilajit; funding not reported in the abstract
• Study: Keller et al. 2019, J Int Soc Sports Nutr; Who took part: 63 recreationally active young men; Preparation and dose: PrimaVie shilajit, 250 or 500 mg a day, versus placebo; Length: 8 weeks; What was reported: In the subgroup of men with higher baseline strength, 500 mg a day was linked to a smaller strength loss after a fatiguing protocol (about 9% versus 16 to 17%); 250 mg showed no difference from placebo; Funding and limits: Funded by the extract's maker; authors declared no competing interests. The headline result came from a subgroup
• Study: Neltner et al. 2024, J Diet Suppl; Who took part: 35 recreationally trained young men; Preparation and dose: Shilajit, 500 or 1,000 mg a day, versus placebo; Length: 8 weeks; What was reported: Higher serum pro-collagen marker (a biomarker, not a measure of tendon or skin health); Funding and limits: Funding not reported in the abstract
• Study: Pingali & Nutalapati 2022, Phytomedicine; Who took part: 60 postmenopausal women with osteopenia; Preparation and dose: Standardised aqueous shilajit extract, 250 or 500 mg a day, versus placebo; Length: 48 weeks; What was reported: Less decline in bone mineral density than placebo; Funding and limits: Funding not reported in the abstract

What the trials add up to, topic by topic:

• Testosterone. The 2016 trial in healthy middle-aged men reported higher testosterone than placebo on a purified shilajit, and we found no independent replication. The 2010 sperm-count study had no control group. A rise in a blood marker isn't the same as feeling or performing better, and none of these abstracts report that it did.
• Fatigue and energy. The "fights fatigue" reputation mostly rests on muscle-fatigue measurements in one trial of young men, where the benefit appeared in a subgroup and at the higher dose. We didn't find a placebo-controlled trial in people with fatigue as a complaint. Open-label pilot studies exist, such as a 28-day trial in 25 men taking shilajit resin, but with no placebo group they can't separate the supplement from expectation (Yadav et al. 2026, Cureus).
• Longevity. We found no human trial that tested whether shilajit changes lifespan or the biology of ageing. The studies above measure hormones, strength, collagen markers and bone density in specific groups.
• Who paid. Keller 2019 was funded by the maker of the extract, and the abstracts of the other trials don't say who paid. Funding doesn't make a result wrong, but a finding applies to that extract, not to any tub with "shilajit" on it.
• Preparation. Trials used purified or processed extracts, in doses of 200 to 1,000 mg a day. The raw resin is a different, much less standardised material.

Heavy metals: what the labs found in the tub

Shilajit comes out of the ground, so asking "what else is in it?" is simply sensible. The results are mixed.

• Reassuring: In a 2026 analysis of twelve shilajit samples from several regions, toxic elements including lead, cadmium and mercury were below established toxicity thresholds, and rare earth elements looked like natural geology, not contamination (Kamgar et al. 2026, J Trace Elem Med Biol).
• Less reassuring: A study of two shilajit kinds sold widely, one from India and one from Pakistan, found toxic elements including arsenic, lead and mercury above the permissible limits it used, with more in the Indian sample (Aldakheel et al. 2022, Biol Trace Elem Res). A 2024 review that gathered published data found reported toxic-metal levels were mostly below WHO and FDA limits for herbal drugs, but a few studies exceeded them. The same review argued that the humic substances may bind some metals, though the evidence on that is unclear (Hussain & Saeed 2024, Biol Trace Elem Res).
• Thallium: A 2025 study of 13 crude samples and six commercial supplements found thallium at up to 0.226 µg/g in crude shilajit and up to 0.5 µg/g in the supplements, with some supplements higher than crude samples. The authors say that justifies regular monitoring and standardised testing. They calculated up to 0.095 µg of thallium in one pill (Kamgar et al. 2025, BMC Chemistry). The paper does not claim any product exceeded a safety limit.

The takeaway isn't "it's contaminated" or "it's clean". Metals vary by origin and product, a supplement can differ from the raw resin it came from, and a lab report tells you more than a mountain photo.

Safety: what the studies report, and where they go quiet

A 2014 review described shilajit's safety as "well documented" in animal and human studies, while asking for better-controlled work on standardised products (Stohs 2014, Phytother Res). The trials above reported no problems at the doses tested, but they were short, and several abstracts say little about safety at all.

Some specifics:

• Pregnancy. A published case report describes a 37-year-old pregnant woman with high blood pressure and low potassium, a "licorice-like" syndrome, after six months of taking a supplement called mumijo, which resolved after she stopped it (Stavropoulos et al. 2018, Gynecol Endocrinol). One case can't show how common this is. It's a reason to ask a doctor before using shilajit in pregnancy, not a measured risk.
• Hormones. Because trials measured testosterone and related hormones, anyone with a hormone-related condition or on hormone-affecting medicine has a good reason to ask a doctor or pharmacist first. Our guide to supplements and drug interactions explains the general method.
• Animal data. A 2026 rat study reported good short-term tolerability but also mild to moderate degenerative changes in liver and kidney tissue on histology, and the authors say it does not rule out tissue effects (Rizun et al. 2026, Pharmaceuticals). That's animals, one study and different samples, mentioned because long-term human safety data are thin.
• Long-term use. The longest controlled trial we found was 48 weeks, in postmenopausal women, and we found no long-term safety data on raw resin.

Before you trust the mountain photo: label questions

If you're comparing tubs, these questions do the most work.

1. Raw resin, powder or purified extract? The trials above used purified or processed shilajit. A tub of resin is not that.
2. Where does it come from, and can the seller show a batch test? Composition varies by region, and in the same analyses supplements differed from raw samples. A certificate of analysis for heavy metals (lead, cadmium, arsenic, mercury) for the specific batch is more informative than a claim about altitude.
3. What does the percentage mean? "Fulvic acid 60%" is a number with no agreed meaning; ask which method and which reference. Compare it with the doses studied in trials, which were weights of an extract, not percentages.
4. Is it sold as a food supplement or as some other food? More on that below.
5. Does the tub say how much to take, how often and who should avoid it? Don't count on it. In the thallium study above, none of the six supplement packs gave any information on chemical composition, heavy metals included.

Our guide to reading supplement labels covers the general approach.

Status in the EU and the Netherlands

Dated 8 October 2026; check current rules before buying or selling.

• EU novel food status. In a consultation under the EU Novel Food Regulation (2015/2283) with Germany as the recipient member state, mumijo (shilajit) was found not to be novel when used as or in food supplements, and novel when used as or in foods other than food supplements. The reasoning was that the file showed no significant EU consumption before 15 May 1997, but Czechia said it had been used in food supplements there before that date (EU consultation document). The consultation document is undated, so check the Commission's Novel Food Status Catalogue for the current entry. The practical point is that the form a product is sold in can change its status.
• Netherlands. The annex to the Dutch Warenwetbesluit Kruidenpreparaten, which lists botanicals that are banned or restricted in herbal preparations, does not name shilajit, mumijo or asphaltum (version in force since 1 July 2022, read 8 October 2026; wetten.overheid.nl). That isn't an approval of any product. We found no NVWA or RIVM statement about shilajit specifically, and a draft new supplement regulation exists that may or may not mention it, so check the current rules with the NVWA.
• Health claims. Which health claims a Dutch seller may make is a separate question from what the studies measured. The benefits reported in this article are research findings, not approved claims.

Where that leaves the tar

Shilajit is interesting and not yet proven. A handful of small trials, some with industry funding, reported higher testosterone markers, better sperm-count figures in an uncontrolled study, a muscle-fatigue effect in a subgroup and less bone loss in one group of women. Better trials would settle a lot.

The product is the variable. Region, processing and batch change what's inside, so studies on one extract don't carry over to a different tub, and metals are the main chemistry question, with both clean and not-clean samples on record. Longevity hasn't been tested in people yet.

Ask a doctor or pharmacist first if you're pregnant, take hormone-related medicine or manage a hormone condition.

Where to read next

Shilajit has neighbours, both in the adaptogen aisle and in the longevity one.

• Functional mushrooms and adaptogens: guide hub, for the six popular ingredients, each with its own guide, and a place to start.
• Ashwagandha: the plant behind the stress and sleep claims, for what the trials tested, what "adaptogen" means and the liver and thyroid cautions.
• Longevity: mechanisms versus human outcomes, for how to read a longevity label as a description of a mechanism rather than an outcome.

Written by Smart Supplements with AI assistance from the sources linked in the text. It has not been reviewed by a clinician.

Last updated: 12 October 2026

This article is for informational purposes only and is not intended as medical advice. Always consult a healthcare professional before starting any new supplement, especially if you take prescription medication.