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What’s guarana and what does it do for the body?
Written byH&B editorial team
Reviewed byHeeral Tomlinson
A caffeine-packed vine from Brazil’s Amazon rainforest, guarana contains up to four times more caffeine than coffee beans. But does it deliver a longer-lasting energy lift? Let’s unpack the buzz
Summary
1What’s guarana?
Guarana is a vine that grows in the Brazilian Amazon. Usually, ‘guarana’ refers to the seeds – these look a bit like eyeballs in a red shell.
2Guarana may reduce tiredness
It’s no surprise that guarana products, including energy drinks and supplements, may help deliver a pick-me-up thanks to their caffeine content.
3Is guarana just caffeine?
Guarana is very high in caffeine – more than coffee beans – but there’s more to it than caffeine alone.
Consider yourself a caffeine fiend? Coffee, tea or energy drinks, most of us rely on a brew to get through the day. But one caffeinated corker you might not have heard of is guarana. Containing up to four times the caffeine in coffee beans, the slightly creepy-looking seed has its own potential benefits.1 So, what’s the buzz about...?
What’s guarana?
Guarana is a vine that grows in the Brazilian Amazon.1 Usually, ‘guarana’ refers to the seeds – these look a bit like eyeballs in a red shell. Traditionally, local tribes brewed these culturally significant seeds to make an energy drink but today you’ll see guarana drinks on supermarket shelves across the world.1 Its secret? The seeds contain up to four times as much caffeine as coffee, making guarana the most caffeine-rich plant in the world.1 You'll find guarana in tablets and capsules, on its own, combined with other ingredients or in some drinks.
What are the potential benefits of guarana?
1. Guarana may reduce tiredness
It’s no surprise that guarana products, including energy drinks and supplements, may help deliver a pick-me-up thanks to their caffeine content. The EU Committee on Herbal Medicinal Products (HMPC) has concluded that guarana seed can be used for the relief of tiredness and weakness.2 However, this is based on long-standing use rather than scientific evidence, so more research is needed to confirm these benefits.
2. Guarana may support alertness and cognitive speed
There’s some evidence to suggest that guarana may support long-term memory, based on studies among healthy adults using 75mg guarana per day (containing 12% caffeine).3,4,5 Guarana (125mg/kg body weight) also improved cyclists’ reaction time compared to a placebo both before and after exercise in a 2022 study.6 However, this data is emerging and more research is needed to form any conclusions.
However, this suggests that guarana might improve some aspects of attention or processing speed. But it’s difficult to tell whether this is because of its caffeine content or whether these potential effects apply to guarana alone.
3. Guarana may have antioxidant effects
Guarana seeds contain a range of antioxidants, including tannins (also found in tea and wine), saponins (found in soy beans) and catechins (found in green tea).1,5,7-11 A small study in 2016 found that guarana may help the body fight harmful molecules called free radicals. These molecules can cause oxidative stress, which is linked to ageing.12 After taking guarana for 15 days, participants also had higher levels of natural antioxidant enzymes – substances in the body that help protect cells from damage.
However, the study was small and only involved people who were overweight, so we need more research to know if the same benefits apply to everyone.
How much guarana’s safe to take?
There are no official guidelines on how much guarana is safe to take, so speak to your doctor before taking guarana supplements and only drink guarana energy drinks in moderation.
Guarana FAQs
You shouldn’t take guarana if you:2,13
- are under 18
- pregnant
- on medication for anxiety
- sensitive to caffeine
- experience stomach or gut ulcers
- have hyperthyroidism (overactive thyroid)
- have cardiovascular problems, including high blood pressure or arrhythmia
- have insomnia
- use stimulant drugs
There are no official reported side effects when taken in recommended doses.2 But, like other high-caffeine substances, taking too much may lead to symptoms like anxiety, heart palpitations, stomach upset and restlessness.14
Guarana is very high in caffeine – more than coffee beans – but there’s more to it than caffeine alone. It’s also a source of certain antioxidants and it can be used for flavour.11 It’s described as bitter and earthy, similar to dark chocolate or coffee.
No type of caffeine is healthier than another, but you might get slightly different benefits or effects from different sources. For example, coffee beans have a different makeup to guarana seeds – but neither’s objectively ‘healthier’ than the other. Instead, pay attention to what’s added to your caffeine source. For example, a black espresso is considered ‘healthier’ than a sweetened latte or a sugary energy drink.
The final say
Next time you spot a guarana energy drink on the shelves, you’ll know a little more about this eyeball-like pick-me-up. Whether you want something to sip whilst you're exercising or you’re interested in daily supplements, it’s always a good idea to check with your doctor first.
Want to broaden your beverage horizons? Browse our ‘natural’ energy drink picks or make a fruity high-protein iced matcha at home...
Disclaimer – This article provides informational advice and is not a substitute for medical care. Working with experts for accuracy, we take great care to ensure the information is up-to-date and relevant. However, you should always consult your GP or healthcare professional before using supplements or alternative products, particularly if you have medical conditions or are under supervision.
1. Smith N, Atroch AL. Guaraná’s Journey from Regional Tonic to Aphrodisiac and Global Energy Drink. Evid Based Complement Alternat Med [Internet]. 2007 Dec 5 [cited 2026 Feb 6]; 7(3): 279-82. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2887323/
2. European Medicines Agency (EMA). Paulliniae semen – herbal medicinal product [Internet]. EMA [cited 2026 Feb 6]. Available from: https://www.ema.europa.eu/en/medicines/herbal/paulliniae-semen
3. Haskell CF, Kennedy DO, Wesnes KA, Milne AL, Scholey AB. A double-blind, placebo-controlled, multi-dose evaluation of the acute behavioural effects of guaraná in humans. J Pyschopharmacol [Internet]. 2007 Jan [cited 2026 Feb 6]; 21(1): 65-70. Available from: https://pubmed.ncbi.nlm.nih.gov/16533867/
4. Kennedy DO, Haskell CF, Wesnes KA, Scholey AB. Improved cognitive performance in human volunteers following administration of guarana (Paullinia cupana) extract: comparison and interaction with Panax ginseng. Pharmacol Biochem Behav [Internet]. 2004 Nov [cited 2026 Feb 6]; 79(3): 401-11. Available from: https://pubmed.ncbi.nlm.nih.gov/15582012/
5. Hack B, Macedo Penna E, Talik T, Chandrashekhar R, Millard-Stafford M. Effect of Guarana (Paullinia cupana) on Cognitive Performance: A Systematic Review and Meta-Analysis. Nutrients [Internet]. 2023 Jan 14 [cited 2026 Feb 6]; 15(2): 434. Available from: https://pubmed.ncbi.nlm.nih.gov/36678305/
6. Gurney T, Bradley N, Izquierdo D, Ronca F. Cognitive effects of guarana supplementation with maximal intensity cycling. Br J Nutr [Internet]. 2023 Jul 28 [cited 2026 Feb 6]; 130(2): 253-60. Available from: https://pubmed.ncbi.nlm.nih.gov/36146946/
7. National Cancer Institute (NIH). Tannin [Internet]. NIH [cited 2026 Feb 6]. Available from: https://www.cancer.gov/publications/dictionaries/cancer-terms/def/tanninhttps://www.cancer.gov/publications/dictionaries/cancer-terms/def/tannin
8. National Cancer Institute (NIH). Saponin [Internet]. NIH [cited 2026 Feb 6]. Available from: https://www.cancer.gov/publications/dictionaries/cancer-terms/def/saponin
9. National Cancer Institute (NIH). Catechin [Internet]. NIH [cited 2026 Feb 6]. Available from https://www.cancer.gov/publications/dictionaries/cancer-terms/def/catechin
10. UC Davis Department of Nutrition. Nutrition & Health Info Sheets for Health Professionals – Catechins and Epicatechins [Internet]. UC Davis Department of Nutrition [cited 2026 Feb 6]. Available from: https://nutrition.ucdavis.edu/outreach/nutr-health-info-sheets/pro-catechins
11. Torres EAFS et al. Effects of the consumption of guarana on human health: A narrative review. Compr Rev Food Sci Food Saf [Internet]. 2022 Jan [cited 2026 Feb 6]; 21(1): 272-95. Available from: https://ift.onlinelibrary.wiley.com/doi/epdf/10.1111/1541-4337.12862
12. Yonekura L et al. Bioavailability of catechins from guaraná (Paullinia cupana) and its effect on antioxidant enzymes and other oxidative stress markers in healthy human subjects. Food Funct [Internet]. 2016 Jul 13 [cited 2026 Feb 6]; 7(7): 2970-8. Available from: https://pubmed.ncbi.nlm.nih.gov/27302304/
13. Drugs.com. Guarana [Internet]. Drugs.com [reviewed 2025 Jul 24; cited 2026 Feb 6]. Available from: https://www.drugs.com/mtm/guarana.html
14. NHS Fife. Caffeine [Internet]. NHS Fife [cited 2026 Feb 6]. Available from: https://www.nhsfife.org/media/f7r7z2nz/caffeine-handout.pdf
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