
Guarana, also known as guarana vine (Paullinia cupana Kunth), is a tropical evergreen climbing plant from the soapberry family (Sapindaceae), native to the Brazilian Amazon. Indigenous tribes have cultivated and used it for centuries, regarding it as a plant with a medicinal purpose. The name “guarana” comes from the word warana, which means “the eyes of God” in the Tupi-Guarani language — a reference to the appearance of its fruits, which resemble a human eye (Malík and Tlustoš, 2023). The fruits are bright red capsules that open as they ripen, revealing one to three black seeds partially covered by a white aril (Erickson et al., 1984). This distinctive appearance gave rise to a legend of the Maués tribe, according to which the shrub grew from a murdered child whose eyes continued to exist in the form of the fruits (Marques et al., 2019a).
The first written reference to guarana dates from 1669 and comes from the Jesuit missionary Johannes Philippus Bettendorf, who described its use against fevers, cramps and headaches. In the 18th century, guarana was also used as a remedy for diarrhoea. Traditionally, its seeds are dried, roasted and ground into a fine powder, which is then added to beverages with stimulating effects. Local people have consumed it since ancient times to increase energy, suppress hunger and improve physical endurance (Marques et al., 2019b).
Botanically, it is a climbing plant with alternate, pinnate leaves composed of three to five smaller leaflets. The small inflorescences, consisting of white to greenish flowers, develop into conspicuous, bright red fruits that usually contain one dark brown to black seed approximately the size of a hazelnut (Luiz Atroch and do Nascimento Filho, 2018).
Guarana seeds contain high concentrations of purine alkaloids, particularly caffeine, theobromine and theophylline (Fig. 1). Their caffeine content ranges from 2–8%, corresponding to approximately 50 mg of caffeine per gram — up to five times the amount found in coffee beans (Baumann et al., 1995). Tannins account for approximately 16% of the seed weight and slow the release of caffeine, thereby prolonging its stimulating effect and reducing sudden fluctuations in energy levels. Condensed tannins include epicatechin, catechin and various procyanidins, which exhibit strong antioxidant and anti-inflammatory properties and therefore help protect cells against oxidative damage (Malík and Tlustoš, 2023; Sangeeth Shyam Sundar et al., 2024).
Guarana also affects the levels of neurotransmitters such as dopamine and noradrenaline, which may improve concentration, memory and reaction abilities (Torres et al., 2022). In addition to methylxanthines and tannins, the seeds also contain polysaccharides, saponins, fatty acids and trace elements such as manganese, rubidium, nickel and strontium, which modulate lipid metabolism and detoxification processes in the body (Arantes et al., 2023; Malík and Tlustoš, 2023).
In terms of physical performance, guarana supplementation has been shown to increase endurance capacity and delay the onset of fatigue. Experiments using animal models, for example, showed that guarana prolonged swimming time to exhaustion. This effect was attributed not only to its stimulating properties but also to the ability of guarana extracts to modulate metabolic processes associated with energy expenditure and oxidative stress (Lima et al., 2005; Torres et al., 2022).
Increased mobilisation of fatty acids from fat stores has also been observed. This contributes to the greater use of lipids as an energy substrate during exercise, thereby conserving muscle glycogen and extending the time to exhaustion (Jagim et al., 2023).
In the area of mental performance, guarana improves cognitive functions, particularly attention, information-processing speed and working memory (Gurney et al., 2023; Hack et al., 2023). Randomised controlled human studies have demonstrated that low doses of guarana increase alertness and cognitive performance without the subsequent decline in attention or onset of fatigue commonly associated with pure caffeine (Talik et al., 2024). Its mechanism of action involves not only the inhibition of adenosine receptors but also the previously mentioned modulation of the dopaminergic and noradrenergic systems (Gurney et al., 2023).
An interesting finding is that positive effects have also been observed with repeated administration, including reduced anxiety and improved overall mood. This suggests that guarana may have potential for managing stress and psychological strain (Pferschy-Wenzig et al., 2022; Torres et al., 2022). Other studies suggest that guarana has neuroprotective effects that could be used in the prevention of neurodegenerative diseases (Costa et al., 2023). For example, models of Alzheimer’s disease have shown slower cognitive decline, reduced amyloid-β accumulation and modulation of inflammatory processes in nervous tissue (Arantes et al., 2023).
Overall, guarana can be considered to have significant potential for supporting physical and mental performance, both when used acutely and as a long-term supplement (Marques et al., 2019a).
The commonly recommended dose of guarana extract is approximately 75 mg per serving, corresponding to about 9 mg of caffeine (Konstantinos and Heun, 2019; Talik et al., 2024). Considering that the maximum safe daily dose of caffeine is generally between 400–600 mg, approximately 66 extract tablets would need to be consumed per day to exceed the safe limit (Lin et al., 2022).
Guarana is safe when used in ordinary amounts, although excessive caffeine intake can cause adverse effects such as insomnia, nervousness or tachycardia (Torres et al., 2022). For these reasons, guarana is not recommended for people with cardiovascular diseases, pregnant or breastfeeding women, or patients with diabetes, insomnia or chronic headaches (Malík and Tlustoš, 2022). It may also affect the metabolism of certain medicines, particularly those acting on the cardiovascular and central nervous systems, such as theophylline, warfarin or certain antidepressants. Caution and consultation with a doctor are therefore necessary when these medicines are taken concurrently (Hladun et al., 2021).
Guarana is often combined with other natural stimulants and nootropics, such as green tea (Camellia sinensis), Asian ginseng (Panax ginseng) or bacopa (Bacopa monnieri) (Brown, 2023; Kennedy et al., 2004; Konstantinos and Heun, 2019). These plants have partly different mechanisms of action — they promote alertness, improve cognitive function and have antioxidant and neuroprotective effects — and their synergistic combination may improve both mental and physical performance (Malík and Tlustoš, 2023).
Another traditional combination is yerba maté (Ilex paraguariensis), which helps reduce the sudden adverse effects of caffeine and provides prolonged stimulation due to its gradual caffeine release (Brown, 2023). Modern dietary supplements often combine guarana with other bioactive ingredients, such as Indonesian ginseng (Panax pseudoginseng), maca (Lepidium meyenii) or adaptogens such as ashwagandha (Withania somnifera). These complex products support energy, cognitive abilities, hormonal balance and overall vitality (Nieman et al., 2024; Wojaczek et al., 2024).
In addition to stimulants, products containing electrolytes or probiotics are also available, further supporting metabolism, immune function and the body’s adaptation to stress (Holkem et al., 2023). Carefully standardised and combined extracts of these plants may provide comprehensive health benefits, with correct dosage and quality control of the individual ingredients being essential (Wang et al., 2023).
Guarana represents a promising area of research due to its potential to support cognitive function and protect neurons against damage and degeneration, particularly in connection with Alzheimer’s and Parkinson’s diseases (Arantes et al., 2023). Its bioactive constituents may act synergistically and influence neuronal metabolism, thereby helping improve cognitive function, especially when optimal doses are used over the long term (Gurney et al., 2023).
Future studies should focus on standardising extracts and optimising doses, as the composition of guarana may vary depending on the plant’s genotype, growing conditions and processing method (Durazzo et al., 2022). It is also important to assess the safety of long-term guarana use in combination with other stimulants or alcohol. With growing interest in natural nootropics, further research is expected to reveal new uses for guarana, both in supporting mental performance and in preventing neurodegenerative diseases (Malík and Tlustoš, 2023).
Written for Kratom World by:
Ing. Matěj Malík, Ph.D.
Research Scientist, Postdoctoral Researcher
Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague (ČZU)
Department of Agroenvironmental Chemistry and Plant Nutrition

This article does not serve as instructions for use or a recommendation for consumption. The information provided is solely for educational and informational purposes. The products mentioned in this article are intended exclusively for collection and study purposes.
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