Yerba mate
Maté, Paraguay tea, Paraguay herb, Jesuit’s tea, Brazil tea, French houx maté; Ilex paraguariensis A. St.-Hil.; in pharmacy Mate folium
- Known today as
- Ilex paraguariensis, an evergreen of the family Aquifoliaceae native to Paraguay, Uruguay, and parts of Brazil and Argentina. Grieve describes a large white-flowered shrub growing wild near streams and widely cultivated, with alternate, large, broadly toothed leaves and a red fruit the size of pepper grains. The leaves, dried by heat and powdered, make the drink; LiverTox finds caffeine in it at about the strength of tea or coffee, with theobromine, theophylline, and polyphenols.
- Kind
- Plant, in 1 older authority
- Constituents
- caffeine, theobromine, theophylline, and 1 more
- Earliest authority here
- Grieve, A Modern Herbal (1931) (A Modern Herbal, 1931)
- In other databases
- Plants of the World Online · GBIF · Wikidata
Caution. Not for people with stomach or duodenal ulcers, high blood pressure, irregular heartbeat or other heart disorders, an overactive thyroid, or conditions needing restricted fluids; not under eighteen, nor in pregnancy or breast-feeding, nor at bedtime. People taking MAO inhibitors should use it with caution, and its caffeine increases the side effects of sympathomimetic drugs. The 2025 meta-analysis recorded mucosal irritation, insomnia, rapid heartbeat, angina, headache, and stomach upset among adverse events. LiverTox rates it a possible but rare cause of clinically apparent liver injury.
Yerba mate: what was it used for?
A stimulating, sustaining drink. Grieve writes that its name yerba “signifies the herb par excellence,” that the consumption in South America is vast, “drunk at every meal and hour,” and that the tea is so sustaining it is sometimes the only refreshment carried on a journey of several days. She gives it as tonic, diuretic, diaphoretic, and “powerfully stimulant,” causing purging and vomiting in large doses.
Yerba mate: what does modern science say?
The European Medicines Agency’s herbal committee accepts the leaf as a traditional herbal medicine, “exclusively based upon long-standing use,” for symptoms of fatigue and weakness and to increase the amount of urine to flush the urinary tract in minor urinary complaints (monograph of 2010). A 2025 meta-analysis of thirteen randomised trials found that in pre-diabetes it may lower post-meal glucose, HbA1c, and insulin resistance, on two trials each, but found no significant effect on blood fats, fasting glucose, waist, or body mass. LiverTox, revised in 2024, notes that the general health claims for it have not been shown in rigorous, adequately powered trials.
Pharmacognosy & Toxicology
- Constituents
- caffeine ChEMBLat about the strength of tea or coffee
- theobromine ChEMBL
- theophylline
- polyphenols
- Mechanism
- Not established in the sources read for this entry.
- Standing
- European Union herbal monograph (2010): traditional use, “exclusively based upon long-standing use,” for fatigue and weakness and to flush the urinary tract in minor urinary complaints.
- European Medicines Agency, Committee on Herbal Medicinal Products. European Union herbal monograph on Mate folium (Maté Leaf). EMA/HMPC/580539/2008, 6 May 2010. Read in full · the text read
- European Medicines Agency, Committee on Herbal Medicinal Products. Assessment report on Mate folium. EMA/HMPC/580545/2008, 6 May 2010. Read in part · the text read
- Li D, et al. (2025). Yerba Maté and its impact on glycemic control and metabolic health: a systematic review and meta-analysis. Frontiers in endocrinology. PMID 41244043. Abstract read · the text read
- LiverTox: Clinical and Research Information on Drug-Induced Liver Injury, “YerbaMate.” National Institute of Diabetes and Digestive and Kidney Diseases, updated 2024. NCBI Bookshelf. Read in full · the text read
The abstract of each source, beneath its citation. For Club members. About the Club or sign in.
Constituent names open the compound’s record at PubChem, and “ChEMBL” beside a name opens its record at ChEMBL, the European Bioinformatics Institute’s database of bioactive molecules. Where a mechanism line was checked against ChEMBL (ChEMBL 37, read 1 October 2026), the check is shown with the measured value and its source paper, or says plainly that nothing has been measured. Doses are as the references give them, for description only; this is not medical advice. Each source carries the result of its check against Crossref, PubMed, or the authority’s page: see Verification.
Yerba mate: what lore surrounds it?
LiverTox records that the drink was first used by the native Guarani people and later popularised by the missionary Jesuits. Grieve adds that two of its North American relatives, Ilex vomitoria and I. dahoon, the cassena and dahoon holly, are emetic, and that a decoction was used by the Indians of North Carolina as yaupon, the ceremonial black drink.
Yerba mate: what did the older authorities say?
- Grieve, A Modern Herbal (1931)
- ‘Maté’ comes from the name of the vessel in which it is infused, with burnt sugar or lemon juice added; it is sucked through a tube, usually of silver, with a bulb strainer at the end, and the cup is passed round. Large sums were paid to the government for leave to gather the leaves, and Paraguay exported five to six million pounds a year.
Sources
- Grieve, M. A Modern Herbal, “Paraguay Tea.” As published on botanical.com. Read in full · the text read
- European Medicines Agency, Committee on Herbal Medicinal Products. European Union herbal monograph on Mate folium (Maté Leaf). EMA/HMPC/580539/2008, 6 May 2010. Read in full · the text read
- European Medicines Agency, Committee on Herbal Medicinal Products. Assessment report on Mate folium. EMA/HMPC/580545/2008, 6 May 2010. Read in part · the text read
- Li D, et al. (2025). Yerba Maté and its impact on glycemic control and metabolic health: a systematic review and meta-analysis. Frontiers in endocrinology. PMID 41244043. Abstract read · the text read
- LiverTox: Clinical and Research Information on Drug-Induced Liver Injury, “YerbaMate.” National Institute of Diabetes and Digestive and Kidney Diseases, updated 2024. NCBI Bookshelf. Read in full · the text read
Verification
- Checked
- October 1, 2026
- Passes
- Every sentence read against its sources, in the pass over the remaining 343 entries
- The Standing line checked against the authority it names (EMA, WHO, FDA, CITES, Commission E)
- Every dated or regulatory claim checked by category across the database
- Sources
- 5 cited: 3 read in full, 1 read in part, 1 abstract read. 1 with the abstract on file.
- Corrections
- None were needed.
What was checked, how, and what was found is set out on the Verification page. A checked source is one whose record was found; it does not make the entry medical advice.
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Cite This Entry
Version 1 · first published October 17, 2026
- Chicago
“Yerba mate.” In Materia Medica, edited by B. C. P. Statema. Version 1. The Thinking Press, 2026–. Last modified October 17, 2026. https://thethinkingpress.org/materia-medica/yerba-mate.
- MLA
“Yerba mate.” Materia Medica, edited by B. C. P. Statema, version 1, The Thinking Press, 17 Oct. 2026, thethinkingpress.org/materia-medica/yerba-mate. Accessed 17 Oct. 2026.
- APA
Yerba mate. (2026, October 17). In B. C. P. Statema (Ed.), Materia medica (Version 1). The Thinking Press. Retrieved October 17, 2026, from https://thethinkingpress.org/materia-medica/yerba-mate
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See Also
Sharing caffeine, theobromine, theophylline
Theobroma cacao · Camellia sinensis · Coffea arabica · Kola nut · Paullinia cupana
Also in M. Grieve
Alder buckthorn in M. Grieve · Witch hazel in M. Grieve · Bearberry in M. Grieve · Sumac in M. Grieve · everything M. Grieve names →
Drawing on the same sources: Grieve
Aconite · Yellow dock · Adder’s-tongue fern · the bibliography →
Nearby in the alphabet
Yew (Taxus baccata) · Yellow stainer (and whose crushed stem base smells of phenol) · Zedoary (of the ginger family, a bitter, camphor-scented root from India) · Abracadabra (one letter shorter each time, into a narrowing triangle) · Yarrow (Achillea millefolium) · Wormwood, oil of (Artemisia absinthium)
Historical description, not medical advice.
