Guarana
What’s New This Month
- Korea: According to Korean government records (translated), solid foods made with guarana and containing 0.15 mg or more caffeine per gram must carry a high-caffeine label from 1 January 2026. 1
- England: The UK government announced on 16 July 2026 that it intends to ban sales of high-caffeine energy drinks to under-16s in England from April 2027. 2
- Australia and New Zealand: FSANZ published its caffeine-review amendment on 9 June 2026. 3
- FDA records: An FDA adverse-event report (not proof of cause) lists a guarana-containing drink. An FDA import alert lists acai sorbet products containing guarana for undeclared or non-permitted colours; the alert means detention at the border, not a recall of shelf product, and does not concern guarana itself. 4 5
- Label survey corrected: A 2026 Korean study of guarana foods used samples bought in 2020 to 2021, before Korea’s rule began. We could not read its counts, so we dropped the earlier figures. 6
Overview
Guarana comes from the seeds of Paullinia cupana, an Amazon plant. It is sold as seed powder, as an extract and as an energy-drink ingredient.
The seeds hold about 2% to 8% caffeine, more than coffee beans. 7
Europe’s herbal monograph, as reported, lists guarana seed as a traditional medicine for tiredness. That label rests on long use, not trials. 8
Labels claim clean energy, focus, memory, mood, better workouts, weight loss and “no crash.”
How We Researched It
We rate each marketing claim with a modified version of GRADE, the system medical researchers use to say how sure we can be (i.e., high, moderate, low or very low), and check each trial with the Cochrane risk-of-bias tool, which asks whether a study’s design could skew its results. For guarana we screened about 55 records and used 25 evidence rows, mostly published from October 2022 through October 2026. We also checked 10 regulators and safety databases. We found no Cochrane guarana review.
Research NotesTop three benefits
Energy GRADE: Low
Three small crossover trials (20 to 32 people) found more alertness or “mental pep” after one dose. In one, 300 mg of extract (about 78 mg of caffeine) sped a simple task and eased mood, but it had no caffeine-only arm. 9 14 15
Bias check: Results were mostly self-rated and short-term. In two trials the guarana dose held 30 mg more caffeine than its caffeine comparison. 14 20
Reaction Time and Alertness GRADE: Low
A 2023 review of 8 placebo trials (328 people) found slightly faster reactions (effect size 0.20), below the 0.3 we count as meaningful. In a 25-person trial, guarana beat placebo but not matched caffeine. 10 9
Bias check: Only two trials matched caffeine, and several share authors. No trial we read reported industry funding.
Memory GRADE: Low
No recent trial tested guarana alone for memory. A 2026 network review’s guarana result rests on one 1996 trial of 45 older adults. The 2023 review found no gain in accuracy or overall thinking. 21 10
Bias check: One old, small trial carries the claim, so the result is fragile.
Benefit Evaluation
| Claim | Claim Verdict | Research Confidence | Supporting Evidence | Safety Risk | Product Quality | FactStack™ Rating |
|---|---|---|---|---|---|---|
| Energy | Promising | Low | Promising | Caution | Variable | Balanced |
| Reaction Time and Alertness | Promising | Low | Promising | Caution | Variable | Balanced |
| Memory | TBD | Low | TBD | Caution | Variable | Balanced |
| Mood | TBD | Very Low | TBD | Caution | Variable | Balanced |
| Exercise Performance | TBD | Very Low | TBD | Caution | Variable | Balanced |
| Weight Loss | TBD | Very Low | TBD | Caution | Variable | Balanced |
| Eye Health | TBD | Very Low | TBD | Caution | Variable | Balanced |
| Cancer-Related Fatigue | TBD | Very Low | TBD | Caution | Variable | Balanced |
| Overall Cognition and Accuracy | Doubtful | Low | Doubtful | Caution | Variable | Negative |
What Sellers Say vs. What Studies Show
| “Natural energy with no crash.” | In a head-to-head trial, guarana did no better than the same dose of plain caffeine. No trial tested a crash. 9 |
| “Boosts memory and brainpower.” | A review of 8 trials found no gain in overall thinking or accuracy. Reactions were only a little faster. 10 |
| “Burns fat.” | The only weight-loss trial mixed guarana with ephedra (ma huang), so guarana alone was not tested. A diet-pill maker helped fund it. 11 |
| “Safe, with few side effects.” | Its caffeine can cause poor sleep, a racing heart and higher blood pressure. A meta-analysis of energy drinks (not guarana alone) found raised blood pressure after consumption. 12 13 |
| “Pure and third-party tested.” | NSF lists no guarana product under its ANSI 173 standard. In one trial, a guarana dose measured 130 mg of caffeine against 100 mg on its label. 14 |
Trial ParametersIf you try it
| Who | Healthy adults who want a short caffeine-type lift. No marketed health benefit is established for any group. |
| Dose | Trials used about 78 to 130 mg of caffeine. Start at 100 mg of caffeine or less, early in the day. 15 14 |
| Ceiling | 400 mg of caffeine a day from all sources, and no more than 200 mg in a single dose. 16 17 |
| Duration | Europe’s monograph, as reported, says see a doctor if fatigue lasts over a week. Stop for chest pain or irregular heartbeat. 8 |
| Form | Choose a product that prints caffeine in mg, since some labels do not state it. Count guarana as caffeine. |
| Ask First | Pregnancy, breastfeeding, under 18; heart disease, high blood pressure or arrhythmia; overactive thyroid; ulcer; MAO inhibitors, other stimulants or warfarin. |
How to Take It
| Pick a plan | Trials used 300 mg of a 26% extract (about 78 mg of caffeine) and 500 mg of powder (about 130 mg). Count it toward the FDA’s 400 mg a day. 15 14 16 |
| Time of day | Take it early in the day. EFSA says 100 mg of caffeine near bedtime may affect sleep. 17 |
| With food | Not reported. |
| What to expect | Short-term energy and alertness may rise. Gains in reaction speed are small. 10 |
| How to take | Choose a product that states caffeine in mg. Two products we read print about 200 mg of caffeine per serving, the single-dose limit. |
Works With / Don’t Mix With
✓ Works with
Not reported. We found no supplement shown to add to guarana’s effect.
Plain coffee. Caffeine at the same dose did about as well in head-to-head trials, and coffee’s dose is easier to count. 9 16
⚠ Ask first / don’t mix
Other caffeine and stimulants. Add up coffee, tea, energy drinks and other stimulants. Keep total caffeine within 400 mg a day. 16
MAO inhibitors (an older type of antidepressant). Europe’s herbal monograph, as reported, advises caution. 8
Heart, thyroid or ulcer problems. Europe’s herbal monograph, as reported, lists heart disease, high blood pressure, overactive thyroid and ulcers as reasons not to use it. 8
Blood thinners such as warfarin. A cancer center’s herb guide says guarana may raise bleeding risk. This is not confirmed in people. 12
Manufacturer Recalls & WarningsLast 36 months, newest first
| Date | Maker / Brand | Product | Action | Src |
|---|---|---|---|---|
| Nov 2025 | ECO FRESH Industria e Comercio de Alimentos Ltda (Brazil) | Acai sorbet with guarana | FDA import alert 45-02: detention at the border for non-permitted colours. Not a recall of shelf product, and not about guarana itself. | 5 |
| Apr 2025 | Not named | Drink containing guarana, ginseng and B vitamins | An FDA adverse-event report (not proof of cause) lists a guarana-containing drink. | 4 |
Where to Buy
We compare products side-by-side not just on price, but on whether NSF lists the product as NSF/ANSI 173 Contents Certified (an independent lab confirms the label matches the contents), whether it is NSF Certified for Sport, whether USP lists it as USP Verified, and whether the seller says it is manufactured in the USA. We leave out a brand’s products for this supplement when, in the last 36 months, the FDA took action against that brand over this supplement (a Class I or II recall, a warning letter, an import alert or an advisory letter). We also leave out any brand with an FDA Class II recall or warning letter on any product. We also leave out any product named in a California Prop 65 notice or a non-US recall, along with that brand’s products of the same ingredient and form. Brands with other actions stay listed and are marked in the Recall Screen column. Our goal remains to provide you, the Consumer, with the information and data necessary to make an informed purchasing decision. Prices reflected below are static and subject to change.
Ratings above describe the ingredient’s research, not any product listed below.
| # | Retailer | Product | Price | NSF 173 | NSF Sport | USP | Mfg. in USA (per seller) | Recall Screen | Affiliate link |
|---|---|---|---|---|---|---|---|---|---|
| 1 | iHerb | Nutricost, Guarana, 150 Capsules (500 mg per Capsule) | $14.95 | ✓ | ✓* | View on iHerb ↗ | |||
| 2 | iHerb | Nutricost, Guarana Powder, 3.5 oz (100 g) | $15.95 | ✓ | ✓* | View on iHerb ↗ | |||
| 3 | HerbsPro | Kal, Guarana, 800 Mg, 120 Tabs | $16.70 | ✓ | ✓ | View on HerbsPro ↗ | |||
| 4 | HerbsPro | Source Naturals, Guarana Energizer, 900 MG, 200 Tabs | $30.09 | ✓ | ✓ | View on HerbsPro ↗ |
Sources
1. Enforcement Rule of the Act on Labeling and Advertising of Foods (Prime Minister’s Ordinance No. 2004). Korea Ministry of Government Legislation (law.go.kr), 30 Dec 2024. www.law.go.kr/LSW/lsInfoP.do?lsiSeq=267855
2. Children’s health further protected with energy drinks ban. UK Department of Health and Social Care, 16 Jul 2026. www.gov.uk/government/news/childrens-health-further-protected-with-energy-drinks-ban
3. Proposal P1056 – Caffeine Review; Notification Circular 397-26 (Amendment No. 250). Food Standards Australia New Zealand, 9 Jun 2026. www.foodstandards.gov.au/food-standards-code/proposals/p1056
4. CAERS adverse-event report 2025-CFS-004185 (openFDA food event record). US Food and Drug Administration (openFDA), 1 Apr 2025. api.fda.gov/food/event.json?search=report_number:%222025-CFS-004185%22
5. Import Alert 45-02 (importalert_118). US Food and Drug Administration, 4 Nov 2025 (page published 1 Oct 2026). www.accessdata.fda.gov/cms_ia/importalert_118.html
6. Lee et al. Caffeine content and label disclosure in 61 guarana products. Food Additives & Contaminants: Part A, 2026. doi.org/10.1080/19440049.2026.2683913
7. Guarana. LiverTox: Clinical and Research Information on Drug-Induced Liver Injury (NBK589113). US National Institutes of Health (LiverTox), 28 Jan 2023. www.ncbi.nlm.nih.gov/books/NBK589113/
8. Paulliniae semen (guarana seed): European Union herbal monograph (EMA/HMPC/897344/2011) and periodic-review addendum (EMA/HMPC/684020/2021). European Medicines Agency, 2013; addendum 2023. www.ema.europa.eu/en/medicines/herbal/paulliniae-semen
9. Gurney et al. Guarana, matched caffeine and placebo on reaction time and alertness: randomized crossover trial. British Journal of Nutrition, 2023. doi.org/10.1017/S0007114522002859
10. Hack et al. Guarana and cognitive performance: meta-analysis of 8 placebo-controlled studies. Nutrients, 2023. doi.org/10.3390/nu15020434
11. Boozer et al. Herbal ephedra (ma huang) with guarana for weight loss: 8-week randomized trial. International Journal of Obesity, 2001. doi.org/10.1038/sj.ijo.0801539
12. Guarana: About Herbs. Memorial Sloan Kettering Cancer Center, 6 May 2022. www.mskcc.org/cancer-care/integrative-medicine/herbs/guarana
13. Gualberto et al. Acute effects of energy drink consumption on cardiovascular parameters in healthy adults: meta-analysis of randomized trials. Nutrition Reviews 82(8):1028-1045, 2024. academic.oup.com/nutritionreviews/article-abstract/82/8/1028/7268826
14. Talik et al. Acute guarana versus low-dose caffeine on cognition, mood and heart-rate variability: crossover trial. Nutrients, 2024. doi.org/10.3390/nu16121892
15. Rekik et al. Guarana extract, thinking speed and passing skill in men: crossover trial. Sports, 2026. doi.org/10.3390/sports14080329
16. Spilling the Beans: How Much Caffeine Is Too Much?. US Food and Drug Administration, 28 Aug 2024. www.fda.gov/consumers/consumer-updates/spilling-beans-how-much-caffeine-too-much
17. Scientific Opinion on the safety of caffeine (EFSA Journal 13(5):4102). European Food Safety Authority, May 2015. www.efsa.europa.eu/en/efsajournal/pub/4102
18. openFDA food and drug enforcement records, search for guarana. US Food and Drug Administration (openFDA), 23 Sep 2026. api.fda.gov/food/enforcement.json?search=product_description:guarana
19. Warning Letters table, filtered for guarana. US Food and Drug Administration, 5 Oct 2026. www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/compliance-actions-and-activities/warning-letters
20. Penna et al. Guarana but not low-dose caffeine improves cycling time-trial performance versus placebo. International Journal of Sport Nutrition and Exercise Metabolism, 2024. doi.org/10.1123/ijsnem.2023-0148
21. Feng et al. Supplements for thinking in older adults: network meta-analysis of 25 trials. Frontiers in Pharmacology, 2026. doi.org/10.3389/fphar.2025.1672171
