{"ok":true,"entry":{"slug":"bcaa","kind":"supplement","name":"bcaa","aliases":["branched-chain amino acids","leucine","isoleucine","valine"],"brands_sg":["California Gold Nutrition","EVLution Nutrition","XTEND","Optimum Nutrition"],"class":"amino acid","tags":["fitness"],"use_for":"training support · gains beyond whole protein unproven","use_after":"timing before or after training is not settled","use_duration":null,"take_with":"complete protein — bcaas alone lack the other eaas","pros":["up to 20 g a day in divided doses appears safe","some 3–6 week studies: 10–14 g a day aided gains","leucine might stimulate protein synthesis in muscle"],"cons":["one review calls the anabolic claim unwarranted","little evidence in endurance-type events","whey and complete proteins already supply them"],"dose_note":"short studies of 3–6 weeks used about 10–14 g a day; up to 20 g a day in divided doses appears safe, and for leucine alone studies suggest an upper safe limit of 500 mg/kg a day — about 38 g for a 75 kg man","dosage":{"ul":null,"unit":"g","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":["beyond 20 g a day — the safety data stop there","not listed on hsa's prohibited/restricted annexes — that list is not exhaustive"],"clashes":[],"sources":[{"id":"nih_ods_bcaa_efficacy","url":"https://ods.od.nih.gov/factsheets/ExerciseAndAthleticPerformance-HealthProfessional/","label":"NIH ODS — Dietary Supplements for Exercise and Athletic Performance (Health Professional), BCAA efficacy","quote":"little evidence to date that supplements of these amino acids improve performance in endurance-related aerobic events … The BCAAs, especially leucine, might also stimulate protein synthesis in exercised muscle","accessed":"2026-08-27"},{"id":"nih_ods_bcaa_mass","url":"https://ods.od.nih.gov/factsheets/ExerciseAndAthleticPerformance-HealthProfessional/","label":"NIH ODS — Exercise and Athletic Performance, BCAA dose and muscle mass","quote":"The results of several short-term studies lasting about 3 to 6 weeks suggest that about 10–14 g/day supplemental BCAAs might enhance gains in muscle mass and strength during training","accessed":"2026-08-27"},{"id":"nih_ods_bcaa_timing","url":"https://ods.od.nih.gov/factsheets/ExerciseAndAthleticPerformance-HealthProfessional/","label":"NIH ODS — Exercise and Athletic Performance, BCAA timing","quote":"it is not clear from existing research whether consumption of protein and BCAAs before versus after a workout affects their ability to maximize muscle protein synthesis and reduce protein catabolism","accessed":"2026-08-27"},{"id":"nih_ods_bcaa_safety","url":"https://ods.od.nih.gov/factsheets/ExerciseAndAthleticPerformance-HealthProfessional/","label":"NIH ODS — Exercise and Athletic Performance, BCAA safety","quote":"Up to 20 g/day BCAA supplements in divided doses appear to be safe … For leucine alone, studies suggest an upper safe limit of intake of 500 mg/kg per day in healthy young and elderly men","accessed":"2026-08-27"},{"id":"nih_ods_bcaa_use","url":"https://ods.od.nih.gov/factsheets/ExerciseAndAthleticPerformance-HealthProfessional/","label":"NIH ODS — Exercise and Athletic Performance, BCAA implications for use","quote":"Studies have not consistently shown that taking supplements of BCAAs or any of their three constituent amino acids singly enhances exercise and athletic performance, builds muscle mass, or aids in recovery from exercise","accessed":"2026-08-27"},{"id":"nih_ods_bcaa_food","url":"https://ods.od.nih.gov/factsheets/ExerciseAndAthleticPerformance-HealthProfessional/","label":"NIH ODS — Exercise and Athletic Performance, BCAAs from food and protein powders","quote":"Consuming animal foods containing complete proteins … automatically increases consumption of BCAAs … This is also true of consuming protein powders made from complete proteins, especially whey, which has more leucine than either casein or soy","accessed":"2026-08-27"},{"id":"wolfe2017","url":"https://www.ebi.ac.uk/europepmc/webservices/rest/PMC5568273/fullTextXML","label":"Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? (Wolfe, JISSN 2017)","quote":"We conclude that the claim that consumption of dietary BCAAs stimulates muscle protein synthesis or produces an anabolic response in human subjects is unwarranted","accessed":"2026-08-27"},{"id":"hsa_hs","url":"https://file.go.gov.sg/hsa-hs-guidelines.pdf","label":"HSA Health Supplements Guidelines (GL-CHPB-3-001 Rev. 020, January 2026), Tables 4–5","quote":"HS for use by the general adult population should not contain vitamins and minerals exceeding the stipulated limits stated in Tables 4 and 5","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), Annexes A/B","quote":"The objective of this guideline is to highlight the substances of concern when used in HS and TM and is not meant to be an exhaustive list","accessed":"2026-08-27"},{"id":"iherb_sg","url":"https://sg.iherb.com/c/bcaa","label":"iHerb Singapore — BCAA category page (default sort, 176 results)","quote":"BCAA … 1 - 48 of 176 results","accessed":"2026-08-27"}],"brand_certs":[{"brand":"XTEND","example":"Xtend® Sport BCAA Blue Raspberry Ice","programme":"NSF Certified for Sport","matching_products":2,"brand_total_certified":6},{"brand":"Optimum Nutrition","example":null,"programme":"NSF Certified for Sport","matching_products":0,"brand_total_certified":2}],"updated_at":"2026-08-30T17:59:38.376296+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."}