Guayusa

For the Amazonian Kichwa, guayusa is a sacred plant associated with strength, vitality, fertility and success ^{27Reference 27Noriega et al. · 2025ReviewGuayusa (Ilex guayusa Loes.): ethnobotany, metabolites and research — reviewView study →}.

Early each morning the daughters-in-law of each family prepare the infusion. While it is drunk, the household tells stories, interprets dreams, dances, prays and weaves, and elders guide the younger members ^{27Reference 27Noriega et al. · 2025ReviewGuayusa (Ilex guayusa Loes.): ethnobotany, metabolites and research — reviewView study →}.

The infusion is also taken as a stomach tonic, to soothe body aches and to clean the mouth. Mixed with ginger, lime juice, chuchuwasi and cane liquor, it is taken for colds ^{27Reference 27Noriega et al. · 2025ReviewGuayusa (Ilex guayusa Loes.): ethnobotany, metabolites and research — reviewView study →}. On the skin it is used as an insect repellent and against snakebite ^{27Reference 27Noriega et al. · 2025ReviewGuayusa (Ilex guayusa Loes.): ethnobotany, metabolites and research — reviewView study →}.

Kichwa hunters wash the heads of their hunting dogs with the infusion, or give them small doses through the nose, to sharpen them for the hunt ^{27Reference 27Noriega et al. · 2025ReviewGuayusa (Ilex guayusa Loes.): ethnobotany, metabolites and research — reviewView study →}.

The Andean Kichwa of the Ecuadorian highlands adopted guayusa as a medicine, mainly for pain ^{27Reference 27Noriega et al. · 2025ReviewGuayusa (Ilex guayusa Loes.): ethnobotany, metabolites and research — reviewView study →}.

The Achuar of Amazonian Ecuador and Peru drink guayusa in a pre-dawn ritual called wayus, which strengthens community ties and purifies the body ^{26,27Reference 26Lewis et al. · 1991Ritualistic use of the holly Ilex guayusa by Amazonian Jívaro Indians — ethnobotanicalView study →Reference 27Noriega et al. · 2025ReviewGuayusa (Ilex guayusa Loes.): ethnobotany, metabolites and research — reviewView study →}.

Men drink copious amounts of a strong leaf decoction and then vomit. The vomiting is learned rather than caused by the plant, and it limits how much caffeine is absorbed ^{26Reference 26Lewis et al. · 1991Ritualistic use of the holly Ilex guayusa by Amazonian Jívaro Indians — ethnobotanicalView study →}. Women drink less and do not vomit ^{27Reference 27Noriega et al. · 2025ReviewGuayusa (Ilex guayusa Loes.): ethnobotany, metabolites and research — reviewView study →}.

The Shuar drink guayusa as a stimulant and for pain, though not as a daily ritual. The Secoya use it for physical ailments, and the Cofán in many drinks ^{27Reference 27Noriega et al. · 2025ReviewGuayusa (Ilex guayusa Loes.): ethnobotany, metabolites and research — reviewView study →}.

The Tsa’chi drink it and use the leaves in steam baths for menstrual complaints ^{27Reference 27Noriega et al. · 2025ReviewGuayusa (Ilex guayusa Loes.): ethnobotany, metabolites and research — reviewView study →}. Among the Shuar, Awajún and Achuar it is used for spiritual cleansing in ceremonies such as the Festival of Victory ^{27Reference 27Noriega et al. · 2025ReviewGuayusa (Ilex guayusa Loes.): ethnobotany, metabolites and research — reviewView study →}.

In mestizo towns of eastern Ecuador the infusion is drunk for pleasure with lemon juice and sugar, and added to liqueurs ^{27Reference 27Noriega et al. · 2025ReviewGuayusa (Ilex guayusa Loes.): ethnobotany, metabolites and research — reviewView study →}.

Bags of prepared guayusa leaves were found in a healer’s tomb in Bolivia, far from where the tree grows, dated to around 500 CE ^{27Reference 27Noriega et al. · 2025ReviewGuayusa (Ilex guayusa Loes.): ethnobotany, metabolites and research — reviewView study →}.

Eighteenth-century mission records describe guayusa for venereal disease and, taken with honey, for infertility. Jesuits in Ecuador sold the leaves in Quito as a cure for sexually transmitted disease ^{27Reference 27Noriega et al. · 2025ReviewGuayusa (Ilex guayusa Loes.): ethnobotany, metabolites and research — reviewView study →}.

In 1857 the British explorer Richard Spruce recorded guayusa plantations near Baños, Ecuador, and described the morning purging ritual ^{27Reference 27Noriega et al. · 2025ReviewGuayusa (Ilex guayusa Loes.): ethnobotany, metabolites and research — reviewView study →}.

In a randomised, double-blind, placebo-controlled crossover trial, 25 adults took 600 mg or 1,200 mg of a guayusa leaf extract ^{1Reference 1Helwig et al. · 2024RCTAcute, dose-response effects of guayusa leaf extract on mood, cognitive and motor-cognitive performance, and blood pressure, heart rate, and ventricular repolarization — randomized, double-blind, placebo-controlled crossover RCTView study →}. The 600 mg dose improved total mood disturbance, fatigue, perceived energy, and motor and psychomotor speed. The 1,200 mg dose improved psychomotor speed and shortened reaction time in a hop test ^{1Reference 1Helwig et al. · 2024RCTAcute, dose-response effects of guayusa leaf extract on mood, cognitive and motor-cognitive performance, and blood pressure, heart rate, and ventricular repolarization — randomized, double-blind, placebo-controlled crossover RCTView study →}.

Jitteriness rose with dose in women only, so the authors judged 600 mg the better dose for mood and cognition ^{1Reference 1Helwig et al. · 2024RCTAcute, dose-response effects of guayusa leaf extract on mood, cognitive and motor-cognitive performance, and blood pressure, heart rate, and ventricular repolarization — randomized, double-blind, placebo-controlled crossover RCTView study →}. Both doses raised systolic and diastolic blood pressure by 4–5 mmHg ^{1Reference 1Helwig et al. · 2024RCTAcute, dose-response effects of guayusa leaf extract on mood, cognitive and motor-cognitive performance, and blood pressure, heart rate, and ventricular repolarization — randomized, double-blind, placebo-controlled crossover RCTView study →}.

A second crossover trial gave a single 650 mg dose of a standardised extract (AmaTea Max). Over two hours it improved working-memory scores and reaction times, and self-rated clarity, focus and mood ^{2Reference 2La Monica et al. · 2023RCTAcute Effects of Naturally Occurring Guayusa Tea and Nordic Lion’s Mane Extracts on Cognitive Performance — randomized, double-blind, placebo-controlled RCTView study →}. It also reduced accuracy on one attention task and raised blood pressure from baseline ^{2Reference 2La Monica et al. · 2023RCTAcute Effects of Naturally Occurring Guayusa Tea and Nordic Lion’s Mane Extracts on Cognitive Performance — randomized, double-blind, placebo-controlled RCTView study →}.

An earlier double-blind crossover trial in 12 men gave 200 mg of caffeine from guayusa leaf extract, green coffee extract or synthetic caffeine. The guayusa caffeine was absorbed the same as synthetic caffeine, but raised epinephrine less ^{3Reference 3Krieger et al. · 2016RCTThe Safety, Pharmacokinetics, and Nervous System Effects of Two Natural Sources of Caffeine in Healthy Adult Males — double-blind crossover clinical trialView study →}.

Polyphenols and theobromine may shape the effects of caffeine in drinks like this, according to a review of caffeinated plants ^{4Reference 4Schuster et al. · 2019ReviewMore than just caffeine: psychopharmacology of methylxanthine interactions with plant-derived phytochemicals — reviewView study →}.

Four completed interventional trials of guayusa extracts are registered on ClinicalTrials.gov.

Gap: every trial is acute and uses a proprietary extract; there is no data on daily use and nothing testing the brewed tea as traditionally drunk.

Guayusa tea preparations carry 54–67 mg gallic-acid equivalents of polyphenols per gram. Their peroxyl-radical scavenging capacity was about half that of green and black teas, and they gave 60–80% protection against oxidative stress in Caco-2 cells, comparable to Camellia sinensis teas ^{5Reference 5Pardau et al. · 2017In vitroAntioxidant and anti-inflammatory properties of Ilex guayusa tea preparations: a comparison to Camellia sinensis teas — in vitro comparative studyView study →}.

The main phenolics are chlorogenic acid and other caffeoylquinic acids, along with quercetin glycosides. Lutein is the main carotenoid ^{6Reference 6García-Ruiz et al. · 2017In vitroGuayusa (Ilex guayusa L.) new tea: phenolic and carotenoid composition and antioxidant capacity — in vitroView study →}.

High antioxidant activity has been reproduced across independent extraction and infusion studies ^{6,7,8,9Reference 6García-Ruiz et al. · 2017In vitroGuayusa (Ilex guayusa L.) new tea: phenolic and carotenoid composition and antioxidant capacity — in vitroView study →Reference 7Kelebek et al. · 2024In vitroExploring the Impact of Infusion Parameters and In Vitro Digestion on the Phenolic Profile and Antioxidant Capacity of Guayusa — in vitroView study →Reference 8Chóez-Guaranda et al. · 2022In vitroEffect of solvent-solvent partition on antioxidant activity and GC-MS profile of guayusa — in vitroView study →Reference 9Arteaga-Crespo et al. · 2020In vitroOptimisation of ultrasound-assisted extraction of phenolic antioxidants from Ilex guayusa — in vitroView study →}, with water-based extracts giving the highest phenolic yield and antioxidant capacity ^{10Reference 10Cadena-Carrera et al. · 2023In vitroGreen-based methods to obtain bioactive compounds from guayusa (caffeine 2.27% of raw leaf) — in vitroView study →}.

Young leaves and some growing sites carry more phenolics ^{11,12Reference 11Villacís-Chiriboga et al. · 2018In vitroChanges in phytochemical composition, bioactivity and in vitro digestibility of guayusa leaves in different ripening stages — in vitroView study →Reference 12de Los Monteros-Silva et al. · 2025In vitroUnlocking the biochemical profile of Ilex guayusa: geographical and ontogenetic factors, antioxidant and α-glucosidase inhibition — in vitroView study →}.

Gap: no human study has measured an antioxidant marker after drinking guayusa.

In lipopolysaccharide-stimulated RAW 264.7 macrophages, guayusa tea preparations reduced nitric-oxide production by 10–30%, comparable to green tea ^{5Reference 5Pardau et al. · 2017In vitroAntioxidant and anti-inflammatory properties of Ilex guayusa tea preparations: a comparison to Camellia sinensis teas — in vitro comparative studyView study →}.

Aqueous and hydroalcoholic extracts of young leaves also showed high anti-inflammatory activity, above 65%, in a laboratory assay ^{11Reference 11Villacís-Chiriboga et al. · 2018In vitroChanges in phytochemical composition, bioactivity and in vitro digestibility of guayusa leaves in different ripening stages — in vitroView study →}.

Gap: no animal or human inflammation study has been published.

In streptozotocin-diabetic mice, guayusa slowed the development of high blood sugar and reduced glycated haemoglobin, excessive eating and drinking, and weight loss. It did not affect blood sugar control in healthy mice ^{13Reference 13Swanston-Flatt et al. · 1989AnimalGlycaemic effects of traditional European plant treatments for diabetes — streptozotocin diabetic mouse modelView study →}.

In a 2025 study of female diabetic rats, guayusa tea (3.0 g/L for 21 days) preserved vascular sympathetic modulation, a marker of outcome in this model, and this correlated with blood sugar. Blood pressure, heart rate and oxidative-stress measures did not change ^{14Reference 14Mello et al. · 2025AnimalIlex Guayusa Tea Improves Glycaemia and Autonomic Modulation in Female Streptozotocin-Induced Diabetic Rats — animal modelView study →}.

Guayusa leaves contain ursolic acid (0.7–1%) and amyrin esters. Ursolic acid was identified as the compound in guayusa extract that activates TGR5, a receptor involved in energy expenditure and insulin sensitivity ^{15,16Reference 15Chianese et al. · 2019In vitroBioactive triterpenoids from the caffeine-rich plants guayusa and maté (ursolic acid, TGR5 activation) — in vitroView study →Reference 16Huang et al. · 2021Triterpenoids from leaves of Ilex guayusa — phytochemical isolationView study →}.

Hydroethanolic leaf extracts inhibited α-glucosidase in vitro, with no effect on α-amylase ^{12Reference 12de Los Monteros-Silva et al. · 2025In vitroUnlocking the biochemical profile of Ilex guayusa: geographical and ontogenetic factors, antioxidant and α-glucosidase inhibition — in vitroView study →}.

Gap: all the data are from rodents or cell assays; there is no human blood-sugar trial.

Ethanolic leaf extracts inhibited Porphyromonas gingivalis and Prevotella intermedia, two bacteria involved in chronic periodontitis, and the extract fractions were also active against Fusobacterium nucleatum ^{17Reference 17Gamboa et al. · 2018In vitroAntimicrobial Activity of Ilex guayusa against periodontal bacteria — in vitroView study →}.

⚠ Extracts of young leaves showed no activity against Escherichia coli or Staphylococcus aureus ^{11Reference 11Villacís-Chiriboga et al. · 2018In vitroChanges in phytochemical composition, bioactivity and in vitro digestibility of guayusa leaves in different ripening stages — in vitroView study →}.

Gap: the activity has been tested only in vitro, against a narrow panel of oral bacteria.

Two in-vitro studies from one Colombian group found that guayusa leaf extract deposited phosphate and orthophosphate minerals on slices of teeth affected by amelogenesis imperfecta ^{18Reference 18Gutiérrez-Prieto et al. · 2022In vitroIn vitro mineral apposition analysis of two Colombian plant extracts on Amelogenesis imperfecta teeth — in vitroView study →}. The extract showed low toxicity to dental pulp stem cells ^{19Reference 19Sequeda-Castañeda et al. · 2024In vitroEvaluation of Colombian plant extracts on dental pulp stem cells — in vitro cytotoxicityView study →}.

A Piper marginatum extract tested alongside it gave better results ^{18Reference 18Gutiérrez-Prieto et al. · 2022In vitroIn vitro mineral apposition analysis of two Colombian plant extracts on Amelogenesis imperfecta teeth — in vitroView study →}.

Gap: the work is confined to tooth slices and cells in one laboratory, with no clinical data.

Toxicology. A standardised guayusa concentrate was negative in the Ames test and in a chromosome-aberration test in human lymphocytes. Its oral LD50 in female rats was above 5,000 mg/kg ^{23Reference 23Kapp et al. · 2016General and Genetic Toxicology of Guayusa Concentrate (Ilex guayusa) — animal and genotoxicity studyView study →}.

In a 90-day rat study, its effects matched those of a caffeine-only control: lower body weight and fat, higher liver enzymes (AST and ALT) and cholesterol, and adaptive enlargement of the salivary glands. Nothing pointed to harm from any other component ^{23Reference 23Kapp et al. · 2016General and Genetic Toxicology of Guayusa Concentrate (Ilex guayusa) — animal and genotoxicity studyView study →}. A guayusa-based drink showed no toxicity in mice at a single dose of 2,000 mg/kg ^{24Reference 24Paladines-Santacruz et al. · 2021AnimalAcute oral toxicity of a novel functional drink based on guayusa — animal modelView study →}.

Record of use. A review for EU novel-food authorisation found no history of adverse effects or safety notifications, and judged its known chemistry no greater a risk than green tea or yerba mate ^{25Reference 25Wise et al. · 2020ReviewA critical review of the composition and history of safe use of guayusa: a stimulant and antioxidant novel food — reviewView study →}.

Caffeine. Single extract doses raised systolic and diastolic blood pressure by 4–5 mmHg ^{1Reference 1Helwig et al. · 2024RCTAcute, dose-response effects of guayusa leaf extract on mood, cognitive and motor-cognitive performance, and blood pressure, heart rate, and ventricular repolarization — randomized, double-blind, placebo-controlled crossover RCTView study →}, and one extract raised blood pressure from baseline ^{2Reference 2La Monica et al. · 2023RCTAcute Effects of Naturally Occurring Guayusa Tea and Nordic Lion’s Mane Extracts on Cognitive Performance — randomized, double-blind, placebo-controlled RCTView study →}. People sensitive to caffeine, and those with heart-rhythm problems, uncontrolled high blood pressure or anxiety, should keep intake moderate or avoid it. EFSA considers up to 400 mg of caffeine a day safe for healthy adults, and notes that 100 mg close to bedtime can disturb sleep in some people ^{30Reference 30EFSA Panel on Dietetic Products et al. · 2015ReviewScientific opinion on the safety of caffeine — regulatory reviewView study →}.

Interactions. No drug-interaction study exists for guayusa, so the interactions known for caffeine apply: added stimulation with other stimulants, and competition with drugs cleared by the same liver enzyme.

Caffeine is cleared mainly by the liver enzyme CYP1A2, and in volunteers the CYP1A2 inhibitor fluvoxamine cut its clearance about fivefold and stretched its half-life from 5 to 31 hours ^{31Reference 31Jeppesen et al. · 1996A fluvoxamine-caffeine interaction study — healthy-volunteer crossover studyView study →}. Anyone taking fluvoxamine or another CYP1A2 inhibitor will feel a cup of guayusa much more strongly and for much longer.