Few side effects of shilajit are well documented, but it has been studied very little: a handful of small, short human trials and a few case reports. The clearest known risk is contamination with heavy metals such as lead, arsenic and mercury. If you are pregnant, breastfeeding, buying for a child, taking medicine or managing a health condition, follow your doctor's advice before taking it.
Below is what the published evidence shows about shilajit's risks, and where it runs out. Where no evidence exists, we say so rather than guess. This is not medical advice, and it gives no dosages.
At a glance
- The human trials that reported on safety were small (25 to 63 people) and short (28 days to 14 weeks); they reported few side effects, all mild.
- Two case reports describe serious events: high blood pressure with low potassium in a pregnant woman taking mumijo, and a possible contribution to anaphylaxis.
- The best-documented risk is heavy metals: a 2022 laboratory study found lead, arsenic and mercury above permissible limits in some Indian and Pakistani samples, and a 2025 study found thallium in some supplements.
- No published study or case report describes an interaction between shilajit and any medicine, so the question is unanswered rather than settled.
- No health body gives shilajit-specific advice for pregnancy, breastfeeding or children; ask a doctor first, and ask for a batch-coded heavy-metal report.
What side effects have been reported in human studies?
Very few, and mild. Most of the trials we opened reported no adverse effects linked to shilajit. A 28-day pilot in 25 men listed mild problems such as acne, rash, itching, indigestion, cough and fever in seven people. All cleared up without treatment, and the researchers judged most unlikely to be related to shilajit.
The human studies we opened that reported on safety are small.
| Study | Design and size | Length | What it reported on safety |
|---|---|---|---|
| Sharma and colleagues, 2003 | Placebo-controlled; 30 healthy volunteers aged 16 to 30 (20 took shilajit, 10 placebo) | 45 days | No significant change in blood pressure, pulse, body weight or blood counts; liver and kidney markers not adversely affected |
| Keller and colleagues, 2019 | Randomised, placebo-controlled; 63 recreationally active men (three groups of 21) | 8 weeks | "There were no reported adverse events" |
| Das and colleagues, 2019 | Randomised, placebo-controlled; 45 women aged 30 to 65 (three groups of 15) | 14 weeks | No adverse effect reported that was directly related to the supplement |
| Open-label pilot, 2026 | Single group, no placebo; 25 healthy men | 28 days | 7 of 25 (28 per cent) had mild, self-limiting events; none serious, none stopped the study |
Two cautions apply. First, these studies were short: the longest lasted 14 weeks. A longer, 48-week trial in women with low bone density exists, but its published summary does not report on side effects. The 2026 pilot's own authors say its 28 days cannot show long-term safety. Second, the Keller study was funded by Natreon Inc., and the Das study partly so. Operation Supplement Safety, a US Defense Department programme, notes more generally that some shilajit study results "could be biased" because the funding came from companies selling shilajit products.
What do case reports say about shilajit?
The published case reports are few, but two describe serious events. A Greek case report describes a pregnant woman with persistent high blood pressure and low potassium after six months of taking mumijo. An Italian report describes a woman whose anaphylaxis may have had shilajit as a contributing factor. Each is a single case.
The Greek report, published in 2018, concerns a 37-year-old woman referred by her obstetricians. After a full work-up, her doctors diagnosed a "licorice-like syndrome" caused by mumijo, another name for shilajit. She was treated with potassium and by stopping the mumijo. The authors called it the first such report in the literature.
The Italian report, from 2019, describes a 43-year-old woman who developed hives after a meal and shilajit, then lost consciousness with breathing difficulty and low blood pressure after exertion. Her doctors diagnosed exercise-induced anaphylaxis, with a possible mast-cell disorder. Prick and patch tests were negative and she declined an oral challenge, so its role was not proven. The authors' conclusion was that such substances "can be cofactors of anaphylaxis in patients with risk factors" (Losa and colleagues, 2019).
Operation Supplement Safety goes a little further. It lists life-threatening allergic reactions, increased blood pressure, disorientation, dizziness and cognitive disorder as adverse effects that shilajit has been "a suspected cause" of. Case reports show that something happened after shilajit, not how often it happens or that shilajit was certainly the cause.
Why are heavy metals the main concern with shilajit?
Because shilajit seeps from sedimentary rock and can contain heavy metals such as lead, cadmium, arsenic and mercury. Laboratory analyses have found lead, arsenic and mercury in some samples above permissible limits, and thallium in some commercial supplements. The FDA warns that heavy metals building up in the body can cause high blood pressure, kidney injury and nerve symptoms.
The analyses disagree on how common the problem is. A 2022 laboratory study of shilajit produced in India and Pakistan reported lead, arsenic and mercury, among other elements, "in amounts that exceeded the standard permissible limit" (Aldakheel and colleagues, 2022). A 2025 laboratory study measured thallium, a toxic metal, in natural shilajit and in shilajit supplements, and found more in some supplements than in the raw material (Kamgar and colleagues, 2025). On the other side, a 2024 review of published studies found reported metal levels in shilajit were below WHO and FDA limits "except in few studies", while concluding that taking shilajit "without knowing permissible levels of metals is not safe".
These are analyses of products, not studies of people, and our PubMed search found no case report tying heavy-metal poisoning to shilajit by name. The wider warnings concern Ayurvedic products in general. The FDA warns that unapproved Ayurvedic products containing harmful levels of heavy metals may cause heavy-metal poisoning, and that these products "typically are not labeled to contain heavy metals". The US National Center for Complementary and Integrative Health notes that some Ayurvedic preparations may contain lead, mercury or arsenic "in amounts that can be toxic".
According to the FDA, the effects of chronic exposure include:
- high blood pressure
- kidney injury
- fatigue
- stomach and gut symptoms such as abdominal pain, constipation, diarrhoea, nausea and vomiting
- nerve symptoms such as tingling in the fingers or toes, weakness in the limbs, dizziness and confusion
The FDA adds that chronic exposure to arsenic may increase the risk of cancer, and that metals in a mother's body may pass into her breast milk.
Does shilajit interact with medicines?
Nobody knows. We found no human study, clinical guideline or case report describing an interaction between shilajit and any specific medicine. That is an absence of evidence, not evidence that it is safe to combine. If you take any prescription medicine, show the product to your doctor or pharmacist before starting.
Operation Supplement Safety lists raised blood pressure as a suspected effect, and the Greek case report involved high blood pressure and low potassium. Neither shows an interaction, but both are reasons for your doctor to know you take it.
Shilajit is also sold as a testosterone product. A 2023 systematic review of such supplements rated one purified shilajit extract "possibly effective" for men with late-onset hypogonadism, a low-testosterone condition (Morgado and colleagues, 2023). We found no study of shilajit in people with hormone-sensitive conditions or on hormone treatment. If either applies to you, that is a question for your doctor.
Who should avoid shilajit or ask a doctor first?
Anyone pregnant or breastfeeding, anyone buying for a child, anyone on prescription medicine, and anyone with high blood pressure, kidney problems, allergies or a mast-cell disorder should ask a doctor before taking shilajit. No health body we found gives shilajit-specific rules for these groups, so the decision belongs with your doctor.
- Pregnancy. We found no guideline that addresses shilajit in pregnancy. We found no trial of shilajit in pregnant women; the 2003 study, for example, enrolled only volunteers who were not pregnant. The only report we found involving pregnancy is the Greek case above. NCCIH advises anyone pregnant or nursing to consult their health care provider, because some Ayurvedic products may contain things that could be harmful.
- Breastfeeding. No body we found addresses shilajit specifically. The FDA's warning that heavy metals in a mother's body may pass into breast milk is the relevant general point.
- Children. We found no published study of shilajit in children. The FDA warns that adults and children can become very sick when heavy metals accumulate in the body.
- High blood pressure or kidney problems. Raised blood pressure is a suspected effect of shilajit, and high blood pressure and kidney injury are among the effects the FDA lists for heavy-metal exposure.
- Allergies or a mast-cell disorder. Allergic reactions are a suspected effect, and the Italian case involved a possible mast-cell disorder.
- Anyone on medicine. Interaction evidence is absent, as above.
If you already take shilajit and notice symptoms such as those in the FDA's list, talk to a doctor and mention the product by name.
How can you lower the risk if you choose to take it?
By knowing what is in the jar. Operation Supplement Safety says that without laboratory testing there is no way to know a shilajit product's actual ingredients or whether it is free of heavy metals. In practice, that means asking for a heavy-metal report for the batch you are buying.
Home checks, explained in our guide on how to identify pure shilajit, can reveal grit or added fat but cannot detect heavy metals. Operation Supplement Safety also suggests looking for a third-party certification seal on the label.
Agree with your doctor whether to take it, rather than relying on a label or a website, including ours. Our article on how shilajit resin is prepared covers dissolving and storage; your doctor's advice comes first.
The short version
The small, short human trials of shilajit reported few side effects, and those were mild, but the longest of those lasted 14 weeks and some were company-funded. Two case reports link shilajit or mumijo to high blood pressure with low potassium, and possibly to anaphylaxis. The best-documented risk is heavy-metal contamination, found in laboratory analyses of some products. There is no published evidence on interactions with medicines, and no health body we found gives shilajit-specific advice for pregnancy, breastfeeding or children, so follow your doctor's advice before taking it.
Sources
Further reading behind the figures above. Himdhara's own numbers — yields, batch results — come from our production records and the batch reports on the lab reports page.
- Operation Supplement Safety, Uniformed Services University (2024). Shilajit as a Dietary Supplement Ingredient. OPSS.
- US Food and Drug Administration. FDA warns about heavy metal poisoning associated with certain unapproved ayurvedic drug products. FDA.
- Stavropoulos K, Sotiriadis A, Patoulias D, et al. (2018). Pseudohyperaldosteronism due to mumijo consumption during pregnancy: a licorice-like syndrome. Gynecological Endocrinology.
- Hussain A, Saeed A (2024). 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.
- National Center for Complementary and Integrative Health. Ayurvedic Medicine: In Depth. NCCIH.