guarana fruit

Guarana: benefits, dosage & side-effects

23 Nov 2022 • 1 min read

Find out all about guarana, including what it does, the benefits to taking it and how much you might need

Written by Jack Feeney on January 14, 2019 Reviewed by Gabriella Clarke on January 31, 2019


What is guarana and what does it do?

Guarana is a rainforest vine growing in the Amazon region in Brazil. Traditionally, Amazonian tribes brewed the seeds of the guarana plant to make an energy drink, and for hundreds of years, Brazilians have used it as an invigorating tonic.1 Its secret ingredient? The seeds contain four times more caffeine than coffee, making guarana the most caffeine-rich plant in the world.2 Guarana is available in tablets and capsules – either on its own or combined with other ingredients, often with ginseng. You can also find it in guarana drinks and smoothies.

Benefits of guarana

What does guarana do in the body?

Guarana seeds contain powerful antioxidants, including tannins, saponins and catechins,3 plus plant chemicals which stimulate the central nervous system, according to a 2010 study by the University of Florida.4 These include:
  • caffeine – guarana seeds contain 2-7.5% caffeine. This is the chief stimulant in guarana
  • theobromine and theophylline – there are traces of these two plant chemicals, both chemically related to caffeine; theobromine is also found in chocolate and tea5,6
As a result of these stimulants, scientists think guarana may have the following effects: It can reduce feelings of tiredness Guarana has energising effects on the body, relieving fatigue and weakness, according to the European Medicines Agency.7 Indeed, a 2008 study by Northumbria University found that people who drank a cocktail of guarana, vitamins and minerals felt less tired after performing a series of mentally challenging tasks than those who drank a placebo.8 It may improve your concentration Guarana could also improve mental performance. In a 2007 study in Nutrients, guarana boosted memory and concentration, although researchers suggested more studies are needed.9 It was also found to improve long-term memory and increase alertness, according to a 2007 study in the Journal of Psychopharmacology.10 It may protect your heart Guarana can help limit the oxidation of harmful LDL cholesterol, according to a 2013 Brazilian study in Lipids in Health and Disease.11 The oxidation of LDL cholesterol occurs when it is damaged by free radicals, which contributes to narrowing and hardening of the arteries – a condition that is linked to cardiovascular disease.12  A 2008 report by the University of Cincinnati also found that guarana can improve blood flow and may even help prevent blood clots.13


How much guarana is safe to take?

There are no official guidelines on how much guarana is safe to consume, but 75mg has been shown to have a positive effect.14 Guarana shouldn’t be taken by:15,16
  • children
  • pregnant women
  • anyone with stomach or gut ulcers
  • people heart problems, including high blood pressure and heart arrhythmia
  • those with an overactive thyroid


What are the side-effects of taking guarana?

Taken in excess, at doses of 250-300mg, guarana can produce similar symptoms to a high-caffeine intake including:17
  • insomnia
  • anxiety
  • heart palpitations
  • increased heart rate and blood pressure
  • stomach upset
Shop Supplements Advice is for information only and should not replace medical care. Please check with your GP before trying any remedies. Sources 1. Smith N, Atroch AL. Guaraná’s Journey from Regional Tonic to Aphrodisiac and Global Energy Drink 2. As above 3. Ryan Raman. Healthline. 12 Benefits of Guarana (Plus Side Effects) 4. As Source 1 5. As Source 1 6. ScienceDirect. Theobromine 7. European Medicines Agency. Paulliniae semen 8. Kennedy DO, et al. Improved cognitive performance and mental fatigue following a multi-vitamin and mineral supplement with added guaraná (Paullinia cupana) 9. Pomportes L, et al. Cognitive Performance Enhancement Induced by Caffeine, Carbohydrate and Guarana Mouth Rinsing during Submaximal Exercise 10. Haskell CF, et al. A double-blind, placebo-controlled, multi-dose evaluation of the acute behavioural effects of guarana in humans 11. Portella Rde L, et al. Guaraná (Paullinia cupana Kunth) effects on LDL oxidation in elderly people: an in vitro and in vivo study 12. Jennifer Moll. VeryWellHealth. The causes and effects of LDL cholesterol 13. Subbiah MT, Yunker R. Studies on the nature of anti-platelet aggregatory factors in the seeds of the Amazonian Herb Guarana (Paullinia cupana) 14. As Source 10 15. As Source 3 16. As Source 7 17. MedlinePlus. Guarana
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