Shilajit Side Effects: What You Should Know

Shilajit is often discussed in connection with a range of potential health-related uses, but as with any food supplement, there may also be side effects. In particular, improper use or poor product quality can be associated with unwanted reactions. This article outlines which shilajit side effects have been reported in the literature and how you may be able to minimise potential risks.

While clinical studies have reported generally positive findings with standardised shilajit extracts, researchers also highlight a number of safety considerations that should be taken into account before use (1,2).

Shilajit Capsules

✓ High-quality, natural Shilajit from the Himalayas

✓ With 50% fulvic acid & 12% humic acid

✓ 500 mg Shilajit extract per capsule

✓ Extract ratio 50:1 (equivalent to 25,000 mg Shilajit resin per capsule)

£18.00

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What is shilajit? Composition & standardisation

Shilajit is a natural rock resin from high mountain regions (including the Himalayas), formed over centuries from plant material. It contains humic substances such as fulvic and humic acids, as well as minerals and organic compounds. Commercially, it is available as a resin, in capsules and as a powder; reputable manufacturers indicate the fulvic acid content (%) and use purified, standardised extracts (1–5). You can find an overview of the effects and dosage of shilajit in our guide.

Next: who should be particularly cautious when considering shilajit?

Who should be cautious? (Contraindications, special groups)

• Known iron overload (e.g. haemochromatosis), transfusion-related iron overload or persistently high ferritin. Ferritin/transferrin saturation should be assessed beforehand (7,8).
• Severe kidney or liver disease: benefits and risks should be evaluated by a doctor.
• Autoimmune diseases, gout/raised uric acid: discuss in advance with a healthcare professional.
• Pregnancy/breastfeeding: not recommended due to lack of data (2).
• Tendency to allergies to ingredients or humic substances: start with a low dose and monitor carefully.

Why this matters: some of the potential risks relate to interactions and iron metabolism – more on this in the next section.

Common side effects

Purified, standardised shilajit has generally been reported as well tolerated over 8–14 weeks in several studies, with no serious adverse events described in those settings (2–5). In practice, sensitive individuals may sometimes experience mild, usually temporary symptoms – often in connection with a dose increase that is too rapid or when taken on an empty stomach.

Gastrointestinal (common)

• Typical symptoms: nausea, loose stools/diarrhoea, abdominal cramps, bloating.
• Possible triggers: increasing the dose too quickly or taking it without food.
• Prevention: increase the amount gradually (see Safe use), take with a meal and ensure adequate fluid intake (2–5).

CNS-related symptoms (occasional)

• Dizziness or tiredness – typically reported in the first 3–7 days of use.
• What to do: reduce the dose for a few days or adjust the time of day (e.g. take in the evening with food); if symptoms persist, seek medical advice (2–5).

Allergic/hypersensitivity reactions (rare)

• Rarely: skin rash, itching, swelling. If suspected, stop taking the product immediately and seek medical assessment (2).

Warning signs: stop immediately and seek medical advice

Continue to the section on interactions to help reduce risks when using shilajit alongside medicines.

Interactions with medicines – what is known

Depending on individual circumstances, shilajit could potentially influence the effects of certain medicines. During the first 2–3 weeks, it can be sensible to monitor yourself more closely and to consult a healthcare professional if you take regular medication.

• Antidiabetic medicines: A potentially additive blood sugar-lowering effect has been discussed; in animal data, a strengthening of the effect of metformin/glibenclamide was observed (6). Practical approach: measure blood glucose more frequently at the beginning (e.g. 2–4 times per week) and, if signs of low blood sugar occur, have your dose checked by a doctor.
• Antihypertensive medicines: Some clinical/physiological studies indicate effects on endothelial function and vascular markers; an additional reduction in blood pressure is considered possible, although the evidence is limited (11). Practical approach: measure blood pressure regularly at home during the first 1–2 weeks.
• Iron supplements: Fulvic and humic acids bind minerals and may influence iron availability; in animal data, fulvic acid acted as a useful iron source, while humic acid altered iron homeostasis (7,8). Practical approach: leave a gap of 2–3 hours between the two intakes and follow lab checks (ferritin/TSAT) as prescribed.
• Anticoagulants/antiplatelet medicines: Evidence for direct interactions is limited and unclear – with long-term medication, discuss use in advance with a doctor.

The next section looks at iron balance – an important topic for certain groups.

Shilajit and its impact on iron balance

Shilajit contains minerals and humic substances; fulvic acid has been shown in animal models to act as a source of iron and to influence iron distribution (7,8). For healthy individuals, this is generally not considered problematic. However, anyone prone to iron overload should be particularly careful.

• Checklist – who should be especially careful?
  • Haemochromatosis or transfusion-related iron overload
  • Raised ferritin/transferrin saturation without a clear cause
• Practical steps: Have ferritin/transferrin saturation checked before starting; if you have a history of disorders of iron metabolism, always discuss use with a doctor.

Why quality matters here: inadequately purified products may contain additional problematic metals.

Quality & contamination: how to choose safely

Quality plays a key role in safety. Analyses of shilajit and shilajit-containing supplements have found measurable levels of thallium as well as variable amounts of essential and potentially toxic metals – routine, independent testing is therefore considered important (9,10).

How can shilajit be used as safely as possible? The next section looks at this in more detail.

Safe use: dosage, timing, titration

• Start low: Begin with 25–50% of the manufacturer’s recommended amount, monitor for 3–7 days and increase gradually if it is well tolerated (2–5).
• Take with a meal: this may help reduce the likelihood of gastrointestinal symptoms.
• Timing: test your own tolerance; if you feel tired, take it in the evening, if you feel more energised, take it in the morning.
• Cycling (optional): for example, 8–12 weeks of use followed by a 1–2 week break; evidence is limited, so this should be decided individually.
• Sensitive groups: kidney/liver disease, autoimmune disease, gout/hyperuricaemia – use only after medical advice.

The next section contains a brief but important note for pregnant and breastfeeding women.

Pregnancy & breastfeeding

How robust is the overall evidence base? The following section summarises this briefly.

How robust is the evidence?

• Several small, placebo-controlled or open-label studies with standardised extracts report good tolerability over 8–48 weeks, with no serious adverse events described (2–5,12).
• Limitations include small sample sizes, heterogeneous preparations/dosages and surrogate endpoints; information on side effects is not always recorded in detail (2–5).

What does this mean in practice? Use cautious dosing, prioritise quality (COA), pay close attention to potential side effects and discuss possible interactions if you take long-term medication.