Shilajit and Medication: What You Should Know About Possible Interactions
Leila WehrhahnUpdated:Key points at a glance:
Shilajit may influence blood pressure and blood sugar levels, and interactions with medicines are possible. Extra caution is advised with anticoagulants and antiplatelet medicines; people taking warfarin are often advised to have their INR monitored. L-thyroxine is typically taken at least 4 hours apart from other supplements, with TSH levels checked after 6 to 8 weeks. Many people start with a low dose, around 250 to 500 mg daily, and keep a record of their values for 2 to 4 weeks. It is advisable to choose only laboratory-tested products with a certificate of analysis (CoA). Pregnant individuals, children, and people with liver or kidney conditions should only use such products after consulting a doctor.
Shilajit is a traditional ayurvedic preparation. If you take medicines regularly, it is worth looking closely at possible interactions. This article explains in clear terms where potential risks may lie, who should be particularly cautious, and how you can test Shilajit in a careful way – including a monitoring checklist and quality criteria.
Who is this article for? For anyone who would like to use Shilajit and who takes medicines regularly – for example for high blood pressure, diabetes, thyroid problems or blood thinning.
- Shilajit may influence blood pressure and blood sugar levels; interactions are possible.1, 2
- Particular caution with anticoagulants (e.g. warfarin/DOACs) and antiplatelet drugs (e.g. aspirin/clopidogrel) – watch for signs of bleeding; with warfarin, INR should be checked more frequently.3, 4
- L‑thyroxine: leave a 4‑hour gap between this and Shilajit, iron or calcium supplements; check TSH after 6–8 weeks.5, 6
- Start low (e.g. 250–500 mg/day of purified Shilajit), record your readings (BP, blood sugar, and if applicable INR/TSH) for 2–4 weeks.
- Look for products tested in a laboratory with a certificate of analysis (CoA) covering heavy metals, PAHs and microbiology.7, 8
Answer 6 questions in the compatibility check:
🧪 Shilajit Compatibility Check
Find out if there are any known risk factors that could contraindicate taking Shilajit.
Question 1 of 8
Why are interactions with Shilajit possible?
Shilajit contains, among other components, fulvic acids and minerals. These may influence the absorption of other substances in the gut (chelation/competition for absorption) and thereby affect medicine levels. Small studies have also described indications of effects on blood pressure, blood sugar and hormone regulation. Specific data on the enzymes/transporters involved are limited; the following notes are therefore partly precautionary recommendations.1, 2, 9
Shilajit may influence the absorption of medicines and affect certain body measurements. Robust data are limited – so it is sensible to proceed step by step with monitoring.
Shilajit Capsules
Who should be particularly cautious?
- Pregnant or breastfeeding people (limited data; possible contamination risk), and children and adolescents under 18 years of age.7
- People with kidney or liver disease.
- People with haemochromatosis/high ferritin levels (consider the iron content).1
- Those with a known tendency to bleed, or immediately after surgery.
- People with immune suppression/organ transplantation (immunomodulatory effects are discussed – only use after medical approval).10
- People with joint inflammation/gout or raised uric acid: close monitoring is advisable as a precaution (data are limited).
🧪 Shilajit Compatibility Check
Find out if there are any known risk factors that could contraindicate taking Shilajit.
Question 1 of 8
The following notes are for guidance and do not replace individual medical advice.
Check your readings particularly closely at the beginning.
Possible interactions by medicine group
Blood pressure medicines (ACE inhibitors, ARBs, beta‑blockers, diuretics)
Some indications suggest that Shilajit may affect blood pressure parameters. In a small study as an add‑on to antihypertensive therapy, changes in oxidative stress were observed; clinically relevant additional blood pressure lowering is considered possible. Start at a low dose, measure your blood pressure 1–2 times daily (morning/evening) and watch for dizziness or fainting episodes.2
Antidiabetic medicines
Insulin and sulfonylureas: a higher risk of low blood sugar is considered possible – during the first 1–2 weeks, measure more frequently and adjust the dose only in consultation with a healthcare professional. Metformin/GLP‑1/SGLT‑2: the risk of low blood sugar is generally lower, but it is still advisable to monitor blood sugar closely. The evidence base is small (preclinical/small studies), so a cautious approach is recommended.9, 11
Anticoagulants (e.g. warfarin, apixaban, rivaroxaban, dabigatran)
Humic substances (related compounds such as humic acids) have shown effects on platelet activation and coagulation in experimental work; the direction and clinical relevance in humans remain unclear and may depend on dose. With warfarin, INR should be checked closely; with DOACs, watch for signs of bleeding (bruising, blood in urine/stool, very heavy periods). Only start after discussing with a doctor or other prescriber.3, 4
Antiplatelet medicines (e.g. aspirin, clopidogrel)
Watch for bruising, nose or gum bleeding and prolonged bleeding times. If any of these occur, stop taking Shilajit and seek medical assessment.3
Thyroid hormones (L‑thyroxine)
Minerals can reduce the absorption of L‑thyroxine. Leave a 4‑hour gap between L‑thyroxine and Shilajit as well as iron and calcium supplements; have TSH checked after 6–8 weeks.5, 6, 12
Immunosuppressants
Shilajit and its components are sometimes discussed as having immunomodulatory properties; robust human data are lacking. After transplantation or with autoimmune diseases, only use after medical approval and with close monitoring.10
Unclear/rare interactions
Psychotropic medicines: no consistent evidence; if you take sedating medicines, start particularly low and watch for daytime sleepiness (theoretical consideration). Testosterone/hormone therapies: some individual studies report hormonal effects of Shilajit; monitoring is mainly relevant if you are already on hormone therapy.13
Be especially cautious with anticoagulants and antiplatelet medicines, monitor more closely if you take blood pressure or diabetes medicines, and keep a 4‑hour gap with L‑thyroxine.
Intake, dosage, timing & monitoring
- Start low: for example 250 mg/day of purified Shilajit; after 3–7 days, increase to 250 mg twice daily (maximum 500 mg/day), depending on tolerance and medical feedback.13
- Take with water; keep a 2–4‑hour gap to L‑thyroxine, iron and calcium (4 hours is preferable for L‑thyroxine).5, 6
- Monitoring in the first 2–4 weeks: blood pressure, blood sugar, and where relevant INR (warfarin) and TSH (for thyroid). Keep a brief diary.
- If you notice issues (marked drops in blood pressure, low blood sugar episodes, signs of bleeding), do not increase the dose or pause and consult a healthcare professional.
Interaction overview (compact)
| Medicine group | Possible interaction | Required monitoring | Interaction level |
|---|---|---|---|
| Blood pressure medicines (ACE inhibitors, ARBs, beta‑blockers, diuretics) | Blood pressure lowering may be enhanced | Blood pressure 1–2×/day, watch for dizziness/fainting | Moderate2 |
| Antidiabetics – insulin/sulfonylureas | Risk of low blood sugar ↑ | Check blood sugar frequently; dose changes only by doctor | Moderate11 |
| Antidiabetics – metformin/GLP‑1/SGLT‑2 | Blood sugar may be affected | Review blood sugar trends | Unclear11 |
| Anticoagulants (warfarin, DOACs) | Clotting may be altered; bleeding risk possible | INR (warfarin), watch for signs of bleeding (DOACs) | High3, 4 |
| Antiplatelet medicines (aspirin, clopidogrel) | Tendency to bleed potentially ↑ | Observe for bruising and mucosal bleeding | Moderate3 |
| Thyroid hormones (L‑thyroxine) | Absorption ↓ through mineral binding | Leave 4‑hour gap; TSH after 6–8 weeks | High5, 6 |
| Iron/calcium supplements | Mutual reduction in absorption | Leave 2–4‑hour gap; ferritin if needed after 8–12 weeks | Moderate5, 12 |
| Immunosuppressants | Immunomodulation possible | Only after medical approval; clinical review | Unclear10 |
| Testosterone/hormone therapy | Hormone status may theoretically be altered | Monitoring mainly if a therapy is already in place | Unclear13 |
Product quality & purity (CoA check)
- Purified product (purification/standardisation, e.g. fulvic acid content), clear batch number and traceability.1
- CoA from an independent laboratory: heavy metals (Pb, Hg, As, Cd), microbiology, pesticides, PAHs (PAH4).7, 8
- PAH limits: within the EU there are maximum levels for food and some food supplements (PAH4, benzo[a]pyrene). Ask for numerical values in the CoA.8
- Avoid unclear information on origin; be aware of reports of heavy metal contamination in ayurvedic products.7, 14
Choose only purified, laboratory‑tested products with a complete CoA (heavy metals, PAHs, microbiology) and clear standardisation.
When to stop and contact a healthcare professional?
- Heavy or persistent bleeding, unusual bruising, black stools.
- Repeated low blood sugar episodes, fainting, chest tightness, palpitations.
- Severe allergic reactions (breathlessness, swelling, rash).
- Persistent severe dizziness, fainting, new neurological symptoms.
Frequently asked questions
Can I take Shilajit with metformin?
This combination is generally considered possible, but you should measure your blood sugar levels more often in the first 1–2 weeks. Clinically relevant low blood sugar is less common with metformin alone than with insulin/sulfonylureas.11
How much time should I leave between L‑thyroxine and Shilajit?
Leave a four‑hour gap between L‑thyroxine and Shilajit/iron/calcium; check TSH after 6–8 weeks.5, 6
Can I combine Shilajit with rivaroxaban/apixaban/warfarin?
Only after medical advice. With warfarin, INR should be checked more frequently; with DOACs, watch clinically for signs of bleeding.3
Does Shilajit raise blood pressure?
Available indications tend to point more towards possible lowering or modulation. Measure your blood pressure regularly, especially if you are already on treatment.2
How can I recognise a “clean” product?
Prefer providers that offer a complete CoA (heavy metals, PAHs, microbiology), clear standardisation (e.g. fulvic acid content) and transparent information on origin.7, 8
What dose is commonly used?
A frequently used range is 250–500 mg/day of purified Shilajit, often split into 2 doses – adjust individually to tolerance and medical advice.13
Back to the most frequent questions
How to check your product’s quality (CoA checklist)
Recommendations for using Shilajit carefully
- Medical advice: if you take medicines regularly, speak to your doctor, pharmacist or other healthcare professional beforehand.
- Quality: look for purified and laboratory‑tested Shilajit. Further information on potential effects can be found in the article Shilajit: potential effects & use; a suitable product is the Shilajit capsules from Nordic Oil.
- Dosage: start low and increase gradually.
- Observation of side effects: typical effects and warning signs are summarised in the article Shilajit: possible side effects.
Conclusion
Shilajit is often used by people looking to support their everyday wellbeing. At the same time, caution is advisable if you are on long‑term medication. Starting slowly, keeping suitable intervals to critical medicines and documenting your measurements can help you to assess Shilajit use in a more informed and cautious way.
Legal notice (EU/UK): Food supplements are not a substitute for a balanced diet and a healthy lifestyle. This article is for information only and does not replace medical advice. Do not make decisions about treatment without consulting a healthcare professional.
Medically reviewed by: Nordic Oil pharmacy team • Last medical review: 01/09/2025
Sources & evidence
- Shilajit: A Natural Phytocomplex with Potential Procognitive Activity (review). Int J Alzheimers Dis. 2012.
- Purified Shilajit in elderly patients with hypertension (RCT, 30 days). Indian J Physiol Pharmacol.
- Humic Acids Inhibit Platelet Activation to Reduce Venous Thromboembolism (animal/ex‑vivo). Front Pharmacol. 2022.
- Humic substances and coagulation times (in vitro). 1990; and Humic substances shorten prothrombin time (in vitro).
- Levothyroxine – Administration (spacing from calcium/iron ≥4 h). StatPearls (updated monograph).
- Calcium formulations reduce levothyroxine absorption (human study). Thyroid. 2011; and PDR monograph.
- Lead, mercury, and arsenic in Ayurvedic medicines sold online. JAMA. 2008; and FDA alert on heavy metals in ayurvedic products.
- EU Regulation No 835/2011: maximum levels for PAHs and consolidated overviews, e.g. Legislation.gov.uk.
- Therapeutic Potential of Fulvic Acid in Chronic Inflammatory Diseases and Diabetes (review). J Diabetes Res. 2018.
- Review on Shilajit used in traditional Indian medicine (critical discussion of immunomodulation). J Ethnopharmacol. 2011.
- Systematic review/meta‑analysis of ayurvedic remedies in T2DM (includes Shilajit sub‑data). Front Pharmacol. 2022.
- NHS leaflet: levothyroxine – influence of calcium/iron and timing.
- Purified Shilajit increases testosterone in healthy volunteers (RCT, 250 mg twice daily). Andrologia. 2015.
- Medsafe (NZ) safety alert on heavy metals in ayurvedic products. 2024.