{"version":"1.0","type":"card","id":"80d7f5f0-83e4-489e-8109-b49d369611fb","url":"https://stacklist.com/card/80d7f5f0-83e4-489e-8109-b49d369611fb","title":"Does caffeine with L-theanine actually help you focus?","source_url":null,"note":"Caffeine and L-theanine are one of the most studied pairings in the energy aisle. Here is what the trials found, how strong the evidence is, and who paid for it.","image":{"url":"https://ucarecdn.com/6eddb44c-2447-41eb-b59f-88021799292a/","alt":"Does caffeine with L-theanine actually help you focus?","width":2000,"height":1333},"stack":{"id":"195fca9b-4b05-451f-aeb0-a6138124d026","title":"The Dose Blog","url":"https://stacklist.com/stack/195fca9b-4b05-451f-aeb0-a6138124d026"},"created_at":"2026-10-13T13:26:03.619Z","updated_at":null,"aco":{"summary":"Caffeine paired with L-theanine shows modest evidence for improving focus and task-switching accuracy in healthy adults, though the effects are narrower than marketing suggests and largely driven by caffeine. Most studies use doses far exceeding what naturally occurs in tea, and several were funded by tea industry organizations.","tags":["caffeine","l-theanine","focus","cognitive-performance","meta-analysis","research-review"],"key_entities":[{"name":"Owen","type":"person","confidence":0.85},{"name":"Giesbrecht","type":"person","confidence":0.85},{"name":"Einöther","type":"person","confidence":0.85},{"name":"Haskell","type":"person","confidence":0.85},{"name":"Unilever","type":"organization","confidence":0.9},{"name":"Lipton Teas and Infusions","type":"organization","confidence":0.9},{"name":"L-theanine","type":"concept","confidence":0.95},{"name":"caffeine","type":"concept","confidence":0.95},{"name":"attention-switching","type":"concept","confidence":0.88},{"name":"task-switching accuracy","type":"concept","confidence":0.88}],"classification":"analysis","language":"en","confidence":0.85,"provenance":{"model":"claude-haiku-4-5","tool":"@stacklist/be@0.1.0","confidence":0.85,"timestamp":"2026-10-13T13:26:08.321Z"},"token_counts":{"approximate":3006,"cl100k":2929},"content_hash":"sha256:547ec45e71fca2bec5d38e36b81faa826300eff652b21ceff75412777daed6db","acp_version":"0.2","body_available":true,"body_tokens":3006,"visibility":"public","agent_accessible":true,"status":"final"},"_links":{"self":"/api/public/card/80d7f5f0-83e4-489e-8109-b49d369611fb.json","html":"https://stacklist.com/card/80d7f5f0-83e4-489e-8109-b49d369611fb","md":"/api/public/card/80d7f5f0-83e4-489e-8109-b49d369611fb.md","stack_json":"/api/public/stack/195fca9b-4b05-451f-aeb0-a6138124d026.json"}}