Shilajit Side Effects: Heavy Metals, Who Should Not Take It

In the human trials, purified shilajit at 200 mg to 1 g a day for 28 days to 48 weeks produced no more side effects than placebo, and the sperm study found liver and kidney blood tests unchanged.^{1, 3, 4} The documented risk arrives with untested material: 20.7% of 193 Ayurvedic products bought online contained detectable lead, mercury or arsenic; raw Indian and Pakistani shilajit exceeded permissible limits for several metals; and a 2025 study found thallium in finished supplements at up to 0.5 micrograms per gram, higher in some than in the raw resin.^{5, 6, 7} The other cautions are precautions rather than recorded harms: iron overload, gout, blood pressure and blood-sugar medicines, pregnancy and breastfeeding, under-18s. What shilajit is and what the trials found is on what is shilajit; the supplements it is sold alongside are in the Wellgard mushroom guide.

What are the side effects of shilajit?

Fewer than the forums suggest, if the material is purified and tested. The 160-patient fracture trial on 1 g a day for 28 days recorded adverse effects no different from placebo (p = 0.839).³ The 60-woman bone trial ran 48 weeks at 250 or 500 mg a day, the longest exposure on record.⁴ The sperm study at 200 mg a day found liver and kidney blood tests unchanged; the muscle study at 500 mg a day found glucose, lipids and muscle-damage markers unchanged.^{1, 2} No trial lists stomach upset, headache, dizziness or low blood pressure as an outcome; those appear on seller websites and in user posts, so they are neither confirmed nor ruled out. The real limit is size: a few hundred people have taken shilajit in a trial, none for longer than 48 weeks.

Does shilajit contain heavy metals?

Raw shilajit can, and so can untested finished products:

• A 2008 survey in JAMA analysed 193 Ayurvedic products bought online: 20.7% contained detectable lead, mercury or arsenic, every one of those exceeded at least one acceptable daily intake standard, and 75% of them claimed good manufacturing practice.⁵
• A 2022 analysis of Indian and Pakistani shilajit found lead, arsenic and mercury, with aluminium, strontium, nickel and chromium, above the permissible limits the authors applied.⁶
• A 2025 study measured thallium, which the usual four-metal panel misses, at up to 0.226 micrograms per gram in raw shilajit and up to 0.5 in commercial supplements, up to 0.095 micrograms per pill; some supplements carried more than the crude material.⁷
• A 2024 review found most reported levels below the limits it quotes for herbal medicines (lead and arsenic 10 parts per million, mercury 1, cadmium 0.2 to 0.3), a minority above, and concluded that consuming shilajit without knowing its metal levels is not safe.⁹

The trials that describe their material used purified, processed or standardised extract; purification separates that material from the raw resin in the contamination studies, so the certificate matters more than the origin story.^{1, 2, 4, 10}

How do you read a certificate of analysis?

A certificate of analysis (CoA) is the laboratory report for one production batch; any brand may publish one or send it on request, and it answers "how do I know it's real?" better than price or packaging. Five checks. The batch number matches the one on your pack; a certificate for another batch proves nothing about yours. The heavy-metal panel lists lead, arsenic, cadmium and mercury with a measured or "less than" figure against a stated limit, in micrograms per gram (parts per million) or per daily serving; "not detected" should come with the detection limit. Whether thallium is on the panel: it rarely is, and the 2025 study is the reason to ask.⁷ The extract is identified, with its fulvic acid percentage. The laboratory is named and accredited, the date recent. "Free from heavy metals" with no figures is a statement, not a test result.

Is shilajit safe to take every day?

Every trial gave it daily: twice a day with meals for 90 days in the testosterone and sperm studies, 48 weeks in the bone trial, 1 g a day for 28 days after fracture surgery.^{1, 3, 4, 10} Nothing there argues against daily use of a tested product at trial doses for the lengths tested. What no trial can tell you is what happens after a year, or what accumulates from an untested product: 0.095 micrograms of thallium in a pill is small once and a different proposition daily for years.⁷ A sensible pattern: a reason to take it, a dose at or below the trial doses, a tested batch, a review after 12 weeks.

Who should not take shilajit?

Iron overload: shilajit's iron content is real but rarely quantified on the label, and people treated for haemochromatosis are usually told to avoid iron supplements; the caution reads the mineral content, not a recorded harm.¹¹ Gout is too much uric acid in the blood; the warning on consumer sites has no trial behind it either way, so anyone with gout should ask first rather than assume it is safe.¹² Erectile dysfunction, low mood and tiredness are reasons to see a GP first; the men's questions are on what shilajit does for men.

Does shilajit affect the liver, kidneys, heart or blood pressure?

Liver: the sperm study found liver tests unchanged, and no published case of liver injury from shilajit was found; the study behind the "shilajit protects the liver" answer online was in rats fed a high-fat diet.^{1, 13} Kidneys: unchanged in the same study, no kidney case found, and nobody with existing liver or kidney disease has been studied, so ask first.¹ Heart and blood pressure: never measured in any shilajit trial, so "can a person with high blood pressure take shilajit?" has no evidence-based yes; ask the pharmacist who knows your medicines. The interaction table on the side effects of mushroom supplements marks every shilajit cell unstudied for this reason. As with any supplement, stop and seek advice for dark urine, pale stools, yellowing skin or eyes, or severe tiredness, and call 999 for swelling of the face or throat or difficulty breathing.

What should you avoid while taking shilajit?

No food, drink or medicine interaction has been documented; none has been studied. The lists on seller websites (no alcohol, no chickpeas, no radish) come from tradition, not research. The evidence-based list is short: untested resin and products with no batch certificate; stacking several mineral-rich supplements if you have iron or gout concerns; taking it alongside a prescribed medicine without telling your pharmacist or GP; pregnancy, breastfeeding and under 18. Never stop a prescribed medicine on the strength of a supplement.

Frequently asked questions

Is shilajit safe for a 20-year-old, and which age is best?

The strength and collagen trials were in men averaging 21, the testosterone trial in men aged 45 to 55; no trial has compared ages or included anyone under 18.^{8, 10} The reason to take it matters more than the age.

Are shilajit gummies safe?

A gummy is only as safe as its batch: the label states the milligrams of extract and the certificate tells you about the metals. The 2025 thallium data show finished products can carry more than raw resin, so check the certificate.⁷

Can women and girls take shilajit?

Adult women outside pregnancy and breastfeeding, yes: the longest trial was 48 weeks in 60 postmenopausal women with no safety signal; under 18, no data.⁴

Is shilajit bad before bed?

No trial measured sleep or reported wakefulness; the twice-daily trial doses included an evening dose with food.^{1, 10}

What should I do if I react to it?

Stop, keep the pack and batch number, and speak to a pharmacist, your GP or NHS 111. Report it through the MHRA Yellow Card scheme, which covers supplements as well as medicines; the batch number lets a contaminated lot be traced.¹⁴

Sources

1. Biswas TK, et al. Clinical evaluation of spermatogenic activity of processed Shilajit in oligospermia. Andrologia, 2010. PubMed 20078516.
2. Das A, et al. The human skeletal muscle transcriptome in response to oral Shilajit supplementation. Journal of Medicinal Food, 2016. PubMed 27414521.
3. 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.
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. PubMed 35933897.
5. Saper RB, et al. Lead, mercury, and arsenic in US- and Indian-manufactured Ayurvedic medicines sold via the Internet. JAMA, 2008. PubMed 18728265.
6. 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.
7. 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.
8. 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.
9. Hussain A, Saeed A. Hazardous or advantageous: uncovering the roles of heavy metals and humic substances in Shilajit (phyto-mineral) with emphasis on heavy metals toxicity and their detoxification mechanisms. Biological Trace Element Research, 2024. PubMed 38393486.
10. Pandit S, et al. Clinical evaluation of purified Shilajit on testosterone levels in healthy volunteers. Andrologia, 2016. PubMed 26395129.
11. NHS. Haemochromatosis. nhs.uk/conditions/haemochromatosis.
12. NHS. Gout. nhs.uk/conditions/gout.
13. Ghezelbash B, et al. Hepatoprotective effects of Shilajit on high fat-diet induced non-alcoholic fatty liver disease (NAFLD) in rats. Hormone Molecular Biology and Clinical Investigation, 2020. PubMed 32083445.
14. MHRA. Yellow Card: report a suspected side effect. yellowcard.mhra.gov.uk.

This article is general information, not medical advice. Shilajit is not taken in pregnancy, while breastfeeding or under 18; if you take any regular medicine or have a liver, kidney, iron or gout condition, ask your pharmacist or GP first, and never stop or change a prescribed medicine on the strength of a supplement.