{"ok":true,"entry":{"slug":"caffeine","kind":"supplement","name":"caffeine","aliases":["caffeine anhydrous","1,3,7-trimethylxanthine"],"brands_sg":["California Gold Nutrition","ALLMAX","JNX Sports","Nutricost","EVLution Nutrition"],"class":"stimulant","tags":["energy","fitness"],"use_for":"endurance, team-sport work and alertness","use_after":"trials most often dose it 60 min before exercise","use_duration":null,"take_with":"water · tea and coffee add to the same daily total","pros":["3–6 mg/kg improved performance across many trials","helps attention and vigilance in most people","works in trained and untrained alike"],"cons":["9 mg/kg brings side-effects, no extra benefit","sleep, jitters and raised blood pressure reported","response varies by genetics and habitual intake"],"dose_note":"trials use about 3–6 mg/kg body mass, most often 60 min before exercise; the ODS sheet cites 2–6 mg/kg; doses near 9 mg/kg raise side-effects without adding benefit","dosage":{"ul":null,"unit":"mg","fda_dv":null,"rda_ai":null,"ul_status":"none_established","population":"general adult","hsa_max_daily":null},"ul_status":"none_established","sg_class":null,"cautions":["raised blood pressure or heart rate — HSA lists both under excessive use","poor sleep or anxiety — insomnia and restlessness are reported","very large single doses — ODS cites death risk near 10–14 g pure caffeine","HSA restricts it: SG labels must state the caffeine amount per product"],"clashes":[{"src":["hsa_restricted"],"food":true,"note":"HSA asks labels to advise limiting concurrent use; the daily total adds up","with":"tea, coffee and other caffeine-containing products"},{"src":["taurine_nma"],"food":true,"note":"80 mg caffeine with 1 g taurine did not improve motor or cognitive performance","with":"taurine (energy-drink doses)"}],"sources":[{"id":"ods_eap","url":"https://ods.od.nih.gov/factsheets/ExerciseAndAthleticPerformance-HealthProfessional/","label":"NIH ODS — Dietary Supplements for Exercise and Athletic Performance (Health Professional)","quote":"Blocks activity of the neuromodulator adenosine; reduces perceived pain and exertion … Might enhance performance in endurance-type activities … risk of death with acute oral dose of approximately 10–14 g pure caffeine","accessed":"2026-08-27"},{"id":"issn_caffeine","url":"https://europepmc.org/article/PMC/PMC7777221","label":"ISSN position stand: caffeine and exercise performance (Guest et al., JISSN 2021)","quote":"Caffeine has consistently been shown to improve exercise performance when consumed in doses of 3–6 mg/kg body mass … Very high doses of caffeine (e.g. 9 mg/kg) are associated with a high incidence of side-effects","accessed":"2026-08-27"},{"id":"hsa_restricted","url":"https://file.go.gov.sg/hsa-chp-prohibited-restricted-ing-guidelines.pdf","label":"HSA — Guidelines on prohibited and restricted ingredients in health supplements and traditional medicines (Oct 2025, Annex A/B)","quote":"Excessive use may cause nervousness, irritability, sleep disturbances, diuresis, increased blood pressure, heart rate and gastrointestinal disturbances … Indicate the amount of caffeine in your product","accessed":"2026-08-27"},{"id":"taurine_nma","url":"https://europepmc.org/article/PMC/PMC12490369","label":"Caffeine and taurine: systematic review and network meta-analysis (Deng et al., JISSN 2025)","quote":"the commonly available CAF and TAU doses in energy drinks, such as Red Bull® (CAF: 80 mg, TAU: 1 g), are ineffective in enhancing motor or cognitive performance","accessed":"2026-08-27"},{"id":"hsa_hs","url":"https://file.go.gov.sg/hsa-hs-guidelines.pdf","label":"HSA — Guidelines on health supplements (Tables 4–5, maximum daily dose limits)","quote":"Table 4: Vitamins Limits … Table 5: Minerals Limits","accessed":"2026-08-27"},{"id":"iherb_sg","url":"https://sg.iherb.com/c/caffeine","label":"iHerb Singapore — Caffeine category (default order)","quote":"California Gold Nutrition … ALLMAX … JNX Sports … Nutricost … EVLution Nutrition","accessed":"2026-08-27"}],"brand_certs":null,"updated_at":"2026-08-29T16:16:14.713299+08:00"},"disclaimer":"kozen-x is not a medical device and does not give medical advice. it lists what published sources have written down. absence of a record is not the same as safe."}