Ayurvedic medicines and heavy metals: what UK patients should know

Ayurveda is based on ancient Indian writings and combines products, mostly from plants but sometimes from animal, metal and mineral sources, with diet, exercise and lifestyle. NIH calls it one of the world's oldest medical systems and notes that it remains one of India's traditional healthcare systems. Many UK users meet it through herbs such as turmeric, ashwagandha or triphala sold as supplements, which are a different matter from the metal-containing preparations discussed here.

Most herbal preparations simply contain plants. The safety conversation changes only when the formulation involves processed metals or minerals, or when a product has been made without quality control, so the heading "Ayurvedic" is not itself the warning sign.

NIH states that the US Food and Drug Administration warns that the metals in some Ayurvedic products make them potentially harmful. A 2015 survey of people using Ayurvedic preparations found that 40 percent had elevated blood levels of lead and some also had elevated mercury. Among the supplements tested, about one in four had high lead and almost half had high mercury. A 2015 case report in the US Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Report linked elevated blood lead in a 64-year-old woman to Ayurvedic preparations bought over the internet. NIH adds that arsenic poisoning from such products, though rare, has been reported.

Those figures describe the products and users studied, not every Ayurvedic item sold. They nonetheless explain why UK public health authorities treat unregulated imported remedies as a distinct route of heavy metal exposure, alongside industrial and household sources.

Lead, mercury and arsenic accumulate in the body. Lead mainly affects the nervous system, blood, kidneys and blood pressure, and children and pregnant women are especially vulnerable. Mercury can injure the brain and kidneys, and arsenic can affect skin, nerves, liver and the heart. Symptoms are often vague at first, such as abdominal pain, constipation, headache, tiredness, irritability, tingling in the hands and feet or memory problems, which is one reason diagnosis is delayed.

Diagnosis is by blood or urine testing arranged through a GP or specialist. Clinicians who treat a patient with unexplained anaemia, abdominal pain, neuropathy or kidney disease are encouraged to ask about herbal products, since the MHRA advises healthcare professionals to enquire about herbal medicine use whenever a reaction is suspected.

Ayurvedic herbal products sold in Great Britain as medicines for minor conditions can be registered under the traditional herbal registration scheme, which requires evidence on safety, quality and traditional use. A registered product carries a THR number and certification mark. The MHRA says THR products are assessed for quality, safety and patient information, whereas other herbal products may be unlicensed or sold as food supplements without that assessment.

The MHRA also warns that the quality of unlicensed herbal products can be poor and variable, that deliberate adulteration with potentially toxic ingredients such as heavy metals and arsenic has occurred, and that product information may be lacking. The NHS advises against buying unlicensed herbal medicines online and recommends asking a pharmacist before using one alongside prescribed medicines.

• A THR number or product licence number shows the product was assessed; its absence on a medicine-style product is a prompt to ask questions.

• Products bought abroad or online may not meet UK standards, and the MHRA may be unable to act against sellers outside the UK.

• Illegal ingredients, including prescription drugs, are most often found in products sold for slimming or erectile dysfunction.

NIH advises not to use Ayurvedic medicine to postpone seeing a conventional healthcare provider, to talk to a conventional provider before using Ayurvedic products if you have a health condition, to take particular care in pregnancy and breastfeeding, and to tell all your healthcare providers about the complementary approaches you use. In practice that means showing your GP or pharmacist the actual packaging and ingredient list.

Ask any practitioner whether a product contains metals or minerals, where it was made, and whether it has been tested for heavy metals, and be cautious if the answers are vague. If you have been taking a product regularly and develop persistent abdominal pain, constipation, anaemia symptoms, numbness or mood and memory change, a GP can arrange blood tests. Children, pregnant women and anyone planning a pregnancy should be assessed promptly if exposure is suspected.

Suspected reactions to herbal products can be reported to the MHRA through the Yellow Card scheme, which asks for the brand name, ingredient list, manufacturer, any registration number and ideally a photograph of the label. For severe reactions, the MHRA suggests keeping a sample in case testing is needed. Call 999 for collapse, seizures, severe breathing difficulty or confusion, and use NHS 111 for urgent advice about a suspected poisoning that is not an emergency.