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What Is Shilajit? Trials, Doses and Why Purity Matters
Shilajit is a blackish-brown, tar-like exudate that seeps from layers of rock in the Himalayas, the Hindu Kush and other mountain ranges, formed gradually from plant and mineral remains; it is a humic substance, not a mushroom, a herb or an animal product.1 Supplements standardise it to fulvic acid, and seven human trials exist: testosterone in men aged 45 to 55 at 500 mg a day for 90 days, sperm counts in 28 infertile men, bone density in 60 postmenopausal women over 48 weeks, fracture union in 160 patients, and strength and collagen markers in young men.2, 3, 4, 5, 6, 7, 8 The heavy-metal reports come from raw resin and untested products, so purification and batch testing come first.9, 10, 12 It sits in the Wellgard mushroom guide because it is sold, searched and stacked alongside mushroom supplements, and because, like them, it has no authorised health claim in Great Britain.
What is shilajit, and why is it in a mushroom guide?
Shilajit (also mumijo, mumie, moomiyo, momiai, mineral pitch or asphaltum) is a mixture of humic substances with plant and microbial metabolites, exuded from rock in mountain regions and collected, cleaned and dried; in Ayurveda it is a rasayana, a rejuvenator.1 It belongs here because shoppers meet it alongside lion's mane and cordyceps, and the same rule applies: the Great Britain nutrition and health claims register has no row for shilajit, mumijo or fulvic acid, so no supplement may attach a health benefit to it.11
What is fulvic acid, and what else is in shilajit?
Fulvic acid is the small, water-soluble fraction of humic matter, the brown material left when plants decompose. Labels standardise shilajit extract to a fulvic acid percentage, often around half, because it is the constituent easiest to measure. The other proposed actives are dibenzo-alpha-pyrones, small aromatic molecules, plus proteins and a long list of minerals.6 Analysed Indian and Pakistani shilajit contained calcium, potassium, magnesium and iron, and also lead, arsenic and mercury above the limits the authors applied.9 A long mineral list on a label describes the material's geology; the trials measured specific outcomes.
What does shilajit do to your body? What the trials measured
| Trial | Who | Dose and length | What changed |
|---|---|---|---|
| Pandit 20162 | Healthy men aged 45 to 55; number not in the abstract | Purified extract 250 mg twice a day (500 mg), 90 days, placebo-controlled | Total and free testosterone and DHEAS higher than placebo; size of the difference not in the abstract; LH and FSH unchanged |
| Biswas 20103 | 35 infertile men with low sperm counts; 28 completed | Processed shilajit 100 mg twice a day (200 mg), 90 days, no placebo | Sperm count +61.4%, motility +12.4 to 17.4%, normal forms +18.9%, testosterone +23.5%; liver and kidney tests unchanged |
| Pingali 20224 | 60 postmenopausal women aged 45 to 65 with osteopenia | Standardised aqueous extract 250 or 500 mg a day, 48 weeks, placebo-controlled | Spine and hip bone density fell on placebo; the fall was smaller at both doses |
| Sadeghi 20205 | 160 adults after tibial fracture surgery, Tehran | Two 500 mg capsules a day (1 g), 28 days, placebo-controlled | Bone union at 129 days against 153 on placebo; side effects no different |
| Keller 20196 | 63 recreationally active men, average age 21 | 250 or 500 mg a day, 8 weeks, placebo-controlled | In the stronger half only, post-fatigue strength loss 8.9% at 500 mg against 17.0% at 250 mg and 16.0% on placebo |
| Neltner 20247 | 35 recreationally trained men, average age 21 | 500 or 1,000 mg a day, 8 weeks, placebo-controlled | A blood marker of collagen synthesis roughly doubled at 500 mg and nearly tripled at 1,000 mg; unchanged on placebo |
| Das 20168 | Overweight US adults; number not in the abstract | Purified extract 250 mg twice a day (500 mg), 8 weeks, then 4 more with exercise, no placebo | 17 connective-tissue genes more active in muscle biopsies at week 8; glucose, lipids and muscle-damage markers unchanged |
Four of the seven (Pandit, Biswas, Pingali and Das) describe their material as purified, processed or standardised extract; the Sadeghi, Keller and Neltner abstracts do not say.
Does shilajit actually work?
For the outcomes above, yes at the doses and durations tested, with the limits the table shows: one unrepeated testosterone trial that does not report the size of the change, one sperm study with no placebo group, one bone trial, and strength and collagen findings measured as markers rather than anything you would feel.2, 3, 4, 6, 7 For what shilajit is most often bought for, energy, libido, erections, sleep and body fat, no trial has measured any of them. The testosterone, sperm and erection questions are set out on what shilajit does for men.
What happens if you take shilajit daily or for 30 days?
The trials ran for 28 days to 48 weeks and measured at the end, so "what to expect after 30 days" has one answer from the data: the fracture trial saw its difference inside 28 days on 1 g a day; everything else was measured at eight weeks or later.5, 6, 7 Daily use at 200 mg to 1 g for up to 48 weeks produced no excess of adverse events over placebo in the trial that counted them, and left liver and kidney tests unchanged where checked.3, 4, 5, 8 Who should take care, and how to read a certificate of analysis, is on shilajit side effects.
When is the best time to take shilajit, and does it affect sleep?
Timing has never been tested. The trials split the dose, morning and evening with meals (250 mg twice a day in the testosterone and muscle trials, 100 mg twice a day after main meals in the sperm study).2, 3, 8 No trial measured sleep, and none reported drowsiness or wakefulness as a side effect, so "does shilajit make you sleepy?" and "is it good before bed?" have no evidence either way. Take it with food, as the trials did.
Purified or raw shilajit: why purity matters
Raw shilajit is scraped from rock and carries whatever the rock carried. A 2008 survey in JAMA of Ayurvedic products in general, not shilajit specifically, analysed 193 bought online: 20.7% contained detectable lead, mercury or arsenic, every one of those exceeded at least one acceptable-intake standard, and three-quarters claimed good manufacturing practice.10 A 2025 study measured thallium, a metal missing from the usual four-metal test, at up to 0.226 micrograms per gram in raw shilajit and up to 0.5 in finished supplements, higher in some products than in the crude material.12 The trials that describe their material used purified, processed or standardised extract; three abstracts do not say.2, 3, 4, 8 So "shilajit" on a label tells you the source; "purified", a fulvic acid percentage and a batch certificate showing lead, arsenic, cadmium, mercury and ideally thallium below stated limits tell you whether it resembles what was trialled.
Resin, gummies or capsules: what each delivers
Resin is the traditional form, a sticky paste dissolved in warm water or milk; the dose depends on the hand unless the label states a weight, and raw material is what the 2022 metal analysis sampled, while the 2025 thallium study sampled raw shilajit and finished supplements alike.9, 12 Capsules and gummies carry a weighed dose of dried extract, so the label states the milligrams per serving and, where standardised, the fulvic acid. No trial compared forms; the useful comparison is the label against the trial doses: 200 mg a day in the sperm study, 250 to 500 mg in the bone trial, 500 mg in the testosterone, strength and collagen trials, 1 g in the fracture trial.2, 3, 4, 5, 6, 7 A gummy that also carries vitamins or minerals may state those nutrients' authorised wording; the shilajit carries none, whatever the form.11
Frequently asked questions
Does shilajit reduce belly fat?
No trial has measured body fat, waist or weight on shilajit alone. The one trial in overweight adults took muscle biopsies and found glucose and lipids unchanged.8
Can women take shilajit?
The longest trial was in women: 60 postmenopausal women took 250 or 500 mg a day for 48 weeks and bone density held better than on placebo.4 It has not been tested in pregnancy or breastfeeding, so it is avoided then.
Is shilajit legal in the UK?
It is sold as a food supplement. Which forms and uses may be sold is decided by the Food Standards Agency's novel-food register, so check the register for the product type; no health claim is authorised for it.11
What is shilajit traditionally used for?
As a rejuvenator in Ayurveda, and in Persian medicine after fracture, which is where the Tehran trial came from.1, 5
Sources
- Agarwal SP, et al. Shilajit: a review. Phytotherapy Research, 2007. PubMed 17295385.
- Pandit S, et al. Clinical evaluation of purified Shilajit on testosterone levels in healthy volunteers. Andrologia, 2016. PubMed 26395129.
- Biswas TK, et al. Clinical evaluation of spermatogenic activity of processed Shilajit in oligospermia. Andrologia, 2010. PubMed 20078516.
- 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. PubMed 35933897.
- Sadeghi SMH, et al. Efficacy of Momiai in tibia fracture repair: a randomized double-blinded placebo-controlled clinical trial. Journal of Alternative and Complementary Medicine, 2020. PubMed 32310691.
- Keller JL, et al. The effects of Shilajit supplementation on fatigue-induced decreases in muscular strength and serum hydroxyproline levels. Journal of the International Society of Sports Nutrition, 2019. PubMed 30728074.
- Neltner TJ, et al. Effects of 8 weeks of Shilajit supplementation on serum pro-c1α1, a biomarker of type 1 collagen synthesis: a randomized control trial. Journal of Dietary Supplements, 2024. PubMed 36546868.
- Das A, et al. The human skeletal muscle transcriptome in response to oral Shilajit supplementation. Journal of Medicinal Food, 2016. PubMed 27414521.
- Aldakheel RK, et al. Rapid determination and quantification of nutritional and poisonous metals in vastly consumed Ayurvedic herbal medicine (rejuvenator Shilajit) by humans using three advanced analytical techniques. Biological Trace Element Research, 2022. PubMed 34800280.
- Saper RB, et al. Lead, mercury, and arsenic in US- and Indian-manufactured Ayurvedic medicines sold via the Internet. JAMA, 2008. PubMed 18728265.
- Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register. gov.uk.
- Kamgar E, Zembrzuska J, Zembrzuski W. Quantifying of thallium in Shilajit and its supplements to unveil the potential risk of consumption of this popular traditional medicine. BMC Chemistry, 2025. PubMed 39827344.
This article is general information, not medical advice. Shilajit has not been tested in pregnancy, breastfeeding or under-18s; anyone taking a regular medicine, or with a liver, kidney, iron or gout condition, should ask a pharmacist or GP first.
