Guayusa Tea Benefits: What the Research Says

Guayusa tea is an Amazonian drink made from the leaves of a holly tree, and it’s increasingly sold as a “clean energy” alternative to coffee. Below we look at what guayusa tea actually contains, what the research says about its benefits, and how much caffeine you’re really getting.

Summary

The short version: guayusa tea is a caffeinated herbal tea with a long history of safe use in Ecuador. Its best-supported benefit is the one you’d expect from caffeine: two small, industry-linked trials found a guayusa extract improved alertness, mood and reaction time for a couple of hours. Most of the other guayusa tea benefits you’ll read about (antioxidant, anti-inflammatory, blood sugar, antibacterial) come from lab-dish and animal studies, not from people drinking the tea.

What is guayusa tea?

Guayusa (say “gwhy-YOU-sah”) is Ilex guayusa, an evergreen tree in the holly family that grows in the upper Amazon, mainly in Ecuador. Its leaves have been brewed as a tea for centuries, and it’s still an everyday drink in Ecuador today [1,2].

Traditionally, guayusa is a morning drink. Anthropologists working with the Achuar (Jívaro) people of Peru and Ecuador described strong leaf brews taken at dawn as a stimulant, with a ritual that also stopped people from taking in too much caffeine [3].

Guayusa is a close cousin of yerba mate (Ilex paraguariensis), another caffeinated holly. When guayusa was assessed for sale in the European Union, Ireland’s food safety authority judged a water extract of the leaves to be substantially equivalent to yerba mate extract, for use as a tea and in food supplements [4].

What’s in guayusa tea?

The main active ingredients are:

• Caffeine, plus a smaller amount of theobromine (the mild stimulant found in chocolate) [1,4].
• Chlorogenic acids, a family of plant compounds also found in coffee. In guayusa leaves, chlorogenic acid is the main polyphenol (a broad group of plant compounds that act as antioxidants in lab tests) [5].
• Flavonoids such as quercetin, and carotenoids (plant pigments), mainly lutein [5].

That makes guayusa chemically similar to other caffeinated hollies like yerba mate and yaupon, which mainly contain polyphenols and caffeine-type alkaloids [6]. How a tea is processed matters too: one study found blanched (briefly heated) guayusa leaves kept most of their polyphenols, while fermented leaves lost a good share [5].

How much caffeine is in guayusa tea?

More than many people expect. In the data reviewed for the EU assessment, guayusa leaf extract contained about 20 to 58 mg of caffeine per 100 mL, compared with about 9 to 15 mg for yerba mate extract [4]. For an 8 oz (240 mL) cup, that works out to roughly 45 to 140 mg, so anywhere from a cup of black tea to a cup of coffee, depending on how strong you brew it.

The guayusa extract capsules used in research are stronger still: 600 mg of extract contained 120 mg of caffeine [7].

Guayusa tea benefits for energy, focus and mood

This is where the human evidence is, and it’s limited to two short-term trials of the same commercial guayusa extract.

• University of Iowa, 2024: 25 young adults took 600 mg or 1,200 mg of guayusa extract (120 or 240 mg caffeine) or a placebo on separate days. Both doses improved mood, perceived energy and speed on reaction tests. The higher dose made women more jittery, and both doses raised blood pressure by about 4 to 5 mmHg. The extract’s maker supplied the capsules [7].
• 2023 trial: a single 650 mg dose of the same extract improved several attention and reaction-time tests, plus self-rated focus and mental clarity, over two hours compared with placebo. It also raised blood pressure from baseline [8].

Neither trial compared guayusa with the same dose of plain caffeine, so we can’t say guayusa does anything that a cup of coffee wouldn’t. Some researchers think compounds like chlorogenic acids and theobromine may smooth out caffeine’s effects, but that idea still needs testing [9]. For background on what caffeine itself can do, see our article on caffeine as an ergogenic aid.

Does guayusa tea fight oxidative stress and inflammation?

Oxidative stress is damage caused by unstable molecules called free radicals; antioxidants help neutralize them. Guayusa leaves score high on standard test-tube antioxidant tests [5].

In a 2017 lab study, guayusa teas had about half the polyphenol-based antioxidant capacity of regular tea (Camellia sinensis), but protected human gut cells from oxidative stress about as well as regular tea did. In mouse immune cells, guayusa reduced nitric oxide (a marker of inflammation) by 10 to 30% [10].

These are cell studies. Nobody has yet shown that drinking guayusa tea lowers oxidative stress or inflammation in people.

Other possible guayusa tea benefits (mostly lab and animal studies)

Antibacterial effects

In a 2018 lab study, guayusa extracts slowed the growth of some bacteria linked to gum disease when applied directly to bacteria in a dish [11]. That doesn’t tell us whether drinking the tea affects your mouth or gut bacteria.

Blood sugar

In a 1989 study, mice fed guayusa showed a slower rise in blood sugar after their insulin-making cells were damaged with a drug (a common lab model of diabetes) [12]. A 2025 study in 13 diabetic rats found guayusa tea helped keep blood sugar from rising over three weeks and was linked to better nerve control of blood vessels [13].

Chlorogenic acid, guayusa’s main polyphenol, is also the compound behind green coffee extract, where human results have been modest at best. There are no human trials of guayusa tea and blood sugar, so it shouldn’t be used to manage diabetes.

Cancer

You may see claims that guayusa has “anti-cancer” properties. These come from lab studies of individual compounds found in many holly plants, not from studies of guayusa tea in people [6]. There’s no evidence that drinking guayusa tea lowers cancer risk.

Guayusa tea side effects and safety

Guayusa tea appears to be about as safe as other caffeinated teas. A 2020 safety review found no history of adverse effects or product safety alerts despite wide use, and concluded its known chemistry poses no greater risk than green tea or yerba mate [1]. In rats given a concentrated guayusa drink for 90 days, the effects seen matched those of the same amount of plain caffeine, with no extra toxicity from the other ingredients [14].

The main thing to watch is the caffeine:

• The US FDA says up to about 400 mg of caffeine a day is not generally linked to negative effects in most healthy adults. Too much can cause a racing heart, jitters, anxiety, upset stomach, headaches and poor sleep [15].
• Count guayusa alongside your coffee, tea, energy drinks and pre-workouts. A few strong cups of guayusa can add up quickly.
• Guayusa can raise blood pressure a little in the short term [7,8], so check with your doctor if you have high blood pressure or a heart condition.
• If you’re pregnant, trying to get pregnant or breastfeeding, talk with your health care provider about how much caffeine is right for you [15].
• Avoid it late in the day if caffeine affects your sleep.

The bottom line on guayusa tea

Guayusa tea is a pleasant, caffeinated holly tea with a long track record of safe use. Its one clear benefit in people is a short-term lift in alertness and mood, which is most likely down to its caffeine. The antioxidant, anti-inflammatory, antibacterial and blood sugar claims are interesting but still rest on lab and animal studies. If you enjoy it, treat guayusa like coffee or green tea: a nice drink, not a health treatment, and keep an eye on your total caffeine.

This article is for general information only and isn’t medical advice. Talk to your doctor or another qualified health professional before starting a new supplement. See our medical disclaimer.

References

1. Wise G, Negrin A. A critical review of the composition and history of safe use of guayusa: a stimulant and antioxidant novel food. Crit Rev Food Sci Nutr. 2020;60(14):2393-2404. doi:10.1080/10408398.2019.1643286
2. Noriega P, Moreno E, Falcón A, et al. Guayusa (Ilex guayusa Loes.) ancestral plant of Ecuador: history, traditional uses, chemistry, biological activity, and potential industrial uses. Molecules. 2025;30(13):2837. doi:10.3390/molecules30132837
3. Lewis WH, Kennelly EJ, Bass GN, et al. Ritualistic use of the holly Ilex guayusa by Amazonian Jívaro Indians. J Ethnopharmacol. 1991;33(1-2):25-30. doi:10.1016/0378-8741(91)90156-8
4. Food Safety Authority of Ireland. Substantial equivalence opinion: Ilex guayusa. 2017. fsai.ie (PDF)
5. García-Ruiz A, Baenas N, Benítez-González AM, et al. Guayusa (Ilex guayusa L.) new tea: phenolic and carotenoid composition and antioxidant capacity. J Sci Food Agric. 2017;97(12):3929-3936. doi:10.1002/jsfa.8255
6. Gan RY, Zhang D, Wang M, Corke H. Health benefits of bioactive compounds from the genus Ilex, a source of traditional caffeinated beverages. Nutrients. 2018;10(11):1682. doi:10.3390/nu10111682
7. Helwig NJ, Schwager LE, Berry AC, et al. Acute, dose-response effects of guayusa leaf extract on mood, cognitive and motor-cognitive performance, and blood pressure, heart rate, and ventricular repolarization. J Int Soc Sports Nutr. 2024;21(1):2379424. doi:10.1080/15502783.2024.2379424
8. La Monica MB, Raub B, Ziegenfuss EJ, et al. Acute effects of naturally occurring guayusa tea and Nordic lion’s mane extracts on cognitive performance. Nutrients. 2023;15(24):5018. doi:10.3390/nu15245018
9. Schuster J, Mitchell ES. More than just caffeine: psychopharmacology of methylxanthine interactions with plant-derived phytochemicals. Prog Neuropsychopharmacol Biol Psychiatry. 2019;89:263-274. doi:10.1016/j.pnpbp.2018.09.005
10. Pardau MD, Pereira ASP, Apostolides Z, et al. Antioxidant and anti-inflammatory properties of Ilex guayusa tea preparations: a comparison to Camellia sinensis teas. Food Funct. 2017;8(12):4601-4610. doi:10.1039/c7fo01067b
11. Gamboa F, Muñoz CC, Numpaque G, et al. Antimicrobial activity of Piper marginatum Jacq and Ilex guayusa Loes on microorganisms associated with periodontal disease. Int J Microbiol. 2018;2018:4147383. doi:10.1155/2018/4147383
12. Swanston-Flatt SK, Day C, Flatt PR, et al. Glycaemic effects of traditional European plant treatments for diabetes. Studies in normal and streptozotocin diabetic mice. Diabetes Res. 1989;10(2):69-73. PubMed 2743711
13. Mello TC, Dias DDS, Bernardes N, et al. Ilex guayusa tea improves glycaemia and autonomic modulation in female streptozotocin-induced diabetic rats. Pharmaceuticals (Basel). 2025;18(3):316. doi:10.3390/ph18030316
14. Kapp RW, Mendes O, Roy S, et al. General and genetic toxicology of guayusa concentrate (Ilex guayusa). Int J Toxicol. 2016;35(2):222-242. doi:10.1177/1091581815625594
15. US Food and Drug Administration. Spilling the beans: how much caffeine is too much? fda.gov