Heavy Metals in Herbal Tea: What Studies Found
What published studies measured for lead, arsenic, cadmium, chromium and aluminum in herbal teas and infusions, how much reaches the cup, and where the findings disagree.
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Short answer. Studies of herbal teas from many countries found measurable metals in the dry herbs, and the risk assessments in most of the abstracts we read judged ordinary tea drinking to be low risk. But some products exceeded reference limits, a few studies reached more worrying conclusions under other assumptions, and the studies cannot tell you about a particular product. We name no brands.
Dry herb versus the cup
Studies measure metals in the dry product and, separately, in the infusion. A study of herbs and teas used in herbal and fruit infusions (chamomile, elderberries, fennel, hibiscus, mate, peppermint, rooibos and rose hip) found that the share of each metal that moved into the infusion varied significantly but was mostly well below 100%. [1] So a number measured in the dry leaf overstates what is in the drink, but it does not show how much is.What the studies found
These are laboratory surveys and risk models. We read the abstracts, not the full papers.| Study (place, year) | What the abstract reports | Strength of evidence |
|---|---|---|
| 47 traditional and herbal teas from 13 countries (2018) | On average herbal teas had higher arsenic (0.26 mg per kg), cadmium (0.19) and lead (2.32) than traditional Camellia sinensis teas. Arsenic, cadmium and lead did not exceed the WHO limit for medicinal plants, except for one herbal tea with 1.1 mg per kg arsenic and 26.4 mg per kg lead. Chromium exceeded Canada's 2 mg per kg limit in 47% of herbal teas, and aluminum in the infusion exceeded a drinking-water guideline in 25% of herbal teas, though modeled weekly aluminum intake stayed below the provisional tolerable level. [2] | Survey with risk model |
| Tea bags of chamomile, lemongrass, anise, boldo and tea sold in Tacna, Peru (2022) | Cadmium exceeded the Codex and WHO level in two chamomile brands (0.210 mg per kg) and one lemongrass brand (0.134); the hazard index was below 1, which the authors read as negligible non-carcinogenic risk, though they call for more detailed studies. [3] | Survey with risk model |
| 17 peppermint tea products in Poland (2023) | Arsenic, lead and cadmium were present in all samples at relatively low levels; the toxicological assessment found no health hazard for weekly exposure. [4] | Survey with risk model |
| 80 rooibos products in South Africa (2021) | Chromium was higher than the WHO permissive limit of 1.3 mg per kg; hazard quotient and hazard index were well below 1, but the authors warn of possible chronic risk from accumulation and suggest regular monitoring. [5] | Survey with risk model |
| 243 coffee, tea and herbal tea products in Iran (2023) | Standard hazard quotients were below 1 and total hazard index showed no risk, but a probabilistic assessment gave a hazard index above 1, and arsenic and nickel had an estimated lifetime cancer risk of medium level. [6] | Survey; modeled risk differs by method |
| Systematic review of 49 papers on herbal teas (2023) | All commonly consumed herbal teas contained metals; the abstract says none met WHO requirements, and also that more than 70% of their health risks were acceptable. The review calls for better cultivation and avoiding low-quality herbal teas. [7] | Systematic review of surveys |
Overall: mixed. Metals are routinely detectable, estimated risks for typical intake were usually low, and results depend on the plant, the origin, the limit used and the modeling method. One abstract reports a probabilistic hazard index above 1 and a medium lifetime cancer risk estimate for arsenic and nickel; these are modeled estimates, not measured harm.
Why the numbers should be read with care
- Plant and part matter. A result for peppermint or rooibos does not transfer to another herb.
- Limits differ. Studies compare to Codex, WHO, Canadian, Mercosur or drinking-water values; the US tea-specific limits are not described in the sources we read.
- Samples are not the market. Each study bought products in one place at one time.
- Metals from other foods add up. The FDA says lead is toxic to people of any age, that the most serious effects occur during active brain development, and that no safe level of lead exposure has been identified. [8] The FDA also says a detected amount of lead does not necessarily mean a food should be avoided, and advises eating a variety of foods to limit exposure to a contaminant from any one food. [8]
Imported and traditional products
Reports on imported herbal teas and traditional medicine products are on separate pages: imported herbal teas and heavy metal concerns and Ayurvedic products and heavy metals. The studies on this page do not single out any tradition.Frequently asked questions
Is there lead in herbal tea?
Studies have detected lead in herbal teas, at widely varying levels. In one 47-tea survey, average lead in herbal teas was 2.32 mg per kg of dry tea, with one herbal tea at 26.4 mg per kg. [2] A Polish study of peppermint tea infusions found low levels and no health hazard for weekly exposure. [4]
Does the metal in the dry tea end up in my cup?
Not all of it. A study of several herbal infusion ingredients found transition rates mostly well below 100%. [1]
Are herbal teas higher in metals than regular tea?
In one survey of 47 teas from 13 countries, herbal teas had higher average arsenic, cadmium and lead than traditional teas, but higher chromium was found in a larger share of traditional teas. [2]
Does the research say herbal tea is unsafe?
No single answer. Most risk assessments in the abstracts found low risk, but one modeling approach in an Iranian study gave a hazard index above 1. [6]
Should I ask someone before giving herbal tea to a child?
Yes, a pharmacist or pediatric clinician can advise. The FDA notes lead is toxic at any age and most harmful during brain development. [8]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety and who should ask a clinician
- Children, pregnancy and breastfeeding. The FDA lead page names in utero exposure, infancy and early childhood as the most sensitive periods. [8] The studies above do not give tea-specific advice for these groups. Ask a pharmacist or clinician, and see children and teens and pregnancy and breastfeeding.
- Heavy drinkers of one tea. An abstract that studied tea consumption said chromium and aluminum intake deserve attention in heavy tea drinkers. [2]
- Quality checks. See testing and certifications and product quality and contamination.
- Whether metals in herbal tea matter for liver or kidney conditions is not described in the sources we read.
For other contaminants in teas see pesticide residues and the quality overview.
References
- Schulzki G, et al. Transition rates of selected metals determined in various types of teas (Camellia sinensis L. Kuntze) and herbal/fruit infusions. Food Chem. 2017;215:22-30. PubMed 27542446. Abstract read 2026-10-23.
- de Oliveira LM, et al. Metal concentrations in traditional and herbal teas and their potential risks to human health. Sci Total Environ. 2018;633:649-657. PubMed 29597162. Abstract read 2026-10-23.
- Portugal ÓB, Flores-Quispe M. Concentrations of arsenic, cadmium, and lead in herbal infusion tea bags marketed in Tacna, Peru. Environ Monit Assess. 2022;194(8):534. PubMed 35764709. Abstract read 2026-10-23.
- Jurowski K, et al. The Toxicological Safety Assessment of Heavy Metal Impurities (As, Pb, and Cd) in Mint Tea Infusions (Mentha piperita L.) Available in Polish Markets. Biol Trace Elem Res. 2023;201(5):2627-2635. PubMed 35779181. Abstract read 2026-10-23.
- Areo OM, Njobeh PB. Risk assessment of heavy metals in rooibos (Aspalathus linearis) tea consumed in South Africa. Environ Sci Pollut Res Int. 2021;28(42):59687-59695. PubMed 34145539. Abstract read 2026-10-23.
- Taghizadeh SF, et al. Assessment of Carcinogenic and Non-carcinogenic Risk of Exposure to Metals via Consumption of Coffee, Tea, and Herbal Tea in Iranians. Biol Trace Elem Res. 2023. PubMed 35462590. Abstract read 2026-10-23.
- Salmani MH, et al. Comparison of Essential and Toxic Metals Levels in some Herbal Teas: a Systematic Review. Biol Trace Elem Res. 2024;202(2):615-623. PubMed 37198356. Abstract read 2026-10-23.
- U.S. Food and Drug Administration. Lead in Food and Foodwares. Page current as of 6 January 2025. Read 2026-10-23.