Siddha Preparations: Herbal, Mineral and Metal-Based Medicines and Their Risks

Urgent first

If someone may have swallowed a toxic product, call Poison Help at 1-800-222-1222 in the US, or 911 in an emergency. In one reported case of metal poisoning from a Siddha product, the signs were severe headache, vomiting, speech trouble, unsteady walking, tremor and a seizure. [1] See poisoning urgent help.

What Siddha preparations include

The Ministry of AYUSH dossier says Siddha drugs come from plants, minerals and animal products, and that compound drugs include poly-herbal, herbo-mineral and mineral preparations. [2] It describes 32 traditional forms of internal medicine, such as decoctions, powders, pills, medicated oils and ghee, and a group it calls exclusive to Siddha: sublimates, consolidations, solidifications, amalgams, calcined caustic compounds, "quintessence" and a "master pill." [2]

Several of these are metal- or mineral-based. Examples in the dossier include parpam (a calcined "calx" prepared from minerals or metals), chendooram (calcined red oxides or sulphides) and kattu (a process that converts volatile mercury and arsenic compounds into a non-volatile form). [2] The dossier calls mercury the "sheet anchor of Siddha therapeutics." [2] A 2026 case review adds that Siddha drug preparation deliberately processes metals, including mercury, mica, copper and arsenic, with herbs, using heating, soaking and grinding. [1]

Most Siddha medicines are not metal-based. Many are herbal. This page is about the metal-based ones because that is where the documented risks sit. We do not give recipes, doses or ways to prepare anything.

How the tradition and government describe safety

The dossier says Siddhars described possible adverse effects when a preparation is made incorrectly, and states that a proper purification process (called chutti), correct dosage and duration will ensure safety, so "perfectly processed drugs can be safely used." [2] That is the tradition's and government's claim. It is not a test of any product you can buy.

What regulators say in India

According to the dossier:

• Siddha drugs are made under licenses from state authorities and regulated under India's Drugs and Cosmetics Act 1940, and Good Manufacturing Practice rules (Schedule T) apply. [2]
• A national board, ASUDTAB, gives technical advice on Ayurveda, Siddha and Unani drugs. [2]
• The government set up a pharmacovigilance (drug safety reporting) scheme from 2017-18, with the National Institute of Siddha as a Siddha centre. [2]
• The dossier itself says it is "the need of the hour" to prove these drugs are safe with comprehensive safety data. [2]
• A 1954 Act restricts misleading advertisements of certain cure claims. [2]

What the documented harms look like

Evidence of harm (case reports). In a 2026 Singapore case, a 58-year-old woman had cerebral edema, seizure and ataxia after taking unlabeled capsules sold as Siddha medicine for their purported anti-cancer effects. Lab analysis found arsenic, mercury and lead far above permissible levels, and her blood lead was very high. [1] She recovered gradually after stopping the capsules and receiving chelation. [1]

The case authors say Siddha has been much less often linked to heavy metal poisoning than Ayurvedic medicine, report only a few previous cases, and note that several studies found safe metal levels in some Siddha formulations. [1] Case reports cannot tell us how common poisoning is, and no one has shown that licensed, tested products are unsafe or safe overall.

A separate 2026 case report describes a skin reaction in a woman taking a Siddha herbo-mineral preparation containing purified sulphur. It cleared when the product was stopped. The authors say limited safety data exist for Siddha medicines. [3]

Evidence from the wider Indian-medicine literature

In a 2008 JAMA study of Ayurvedic medicines sold online, about one in five (20.7%) of 193 products tested had detectable lead, mercury or arsenic, and every metal-containing product exceeded at least one standard for acceptable daily intake. [4] That study tested Ayurvedic, not Siddha, products. We cite it because both traditions use similar metal-processing ideas. NCCIH likewise warns about lead, mercury and arsenic in some Ayurvedic preparations. [5]

Practical cautions

• A label, a "traditional" claim or a seller's word is not proof of testing. Unlabeled capsules were the problem in the Singapore case. [1]
• Tell your doctor and pharmacist about every Siddha product, because herbs and minerals can interact with prescribed medicines. [6]
• Pregnancy, breastfeeding, children, kidney or liver disease and long-term medicines call for a clinician's advice first. See Ayurveda, pregnancy and children for a closely related discussion.
• Do not stop or swap a prescribed medicine for a Siddha product.
• If you have symptoms that could be metal poisoning, tell a clinician what you have taken. A product sample helps testing. [1]

Read heavy metals in traditional medicines, Ayurvedic heavy metals and product quality and product quality and contamination.

Finding a practitioner or "Siddha near me"

We do not list sellers or practitioners. Ask who made the product, whether it is licensed where you live, and whether a batch has been tested for metals. See questions to ask a traditional healer.