English version in progress: interface and data are in English; some explanatory text is still in Chinese.
Caffeine
白天大脑里积累的腺苷会让人犯困；咖啡因占住腺苷的受体，暂时挡住这个信号。
Full ranking Dose tool Products (1,071)
Key facts
Daily Value (US FDA)—
Tolerable Upper Intake Level (UL)— Authoritative daily maximum: 400 mg
Median（Per day）150 mgP5 30 – P95 388
Products1,071
Sources: https://doi.org/10.2903/j.efsa.2015.4102 · EFSA 2015: 200 mg single dose / 400 mg/day no safety concern (adults)
How it works：咖啡因为什么能让人不困？
- 咖啡因从胃肠道快速、几乎完全吸收。
- 它阻断大脑中的腺苷受体，从而减少困倦信号。
- 主要在肝脏经 CYP1A2 代谢；代谢速度因人、孕期、吸烟等差别很大。
Schematic only; positions and scale are not anatomical.
Limits and cautions：FDA 认为健康成人每天不超过 400 mg 通常不会带来危险；孕期、儿童和敏感人群应更少。
Sources：EFSA Scientific Opinion on the safety of caffeine (2015)；FDA: Spilling the Beans: How Much Caffeine is Too Much?
Daily dose across products（mg/day）
Authoritative daily maximum 400
13.8 mglog scale · n=1,071833 mg
Label data from official national databases and brand websites, as declared; not lab-verified.
Top ranked
| Rank | Brand | Product | Per day | Score |
|---|---|---|---|---|
| 1 | Nuun | Sport +Caffeine Wild Berry | 120 mg | 85.0 |
| 2 | Healthy Body Services Inc. | Allmax Therma Pro | 200 mg | 84.0 |
| 2 | NutraChamps Inc. | Caffeine + L-Theanine | 100 mg | 84.0 |
| 2 | Vita Health Products Inc. | Caffeine 100 mg | 100 mg | 84.0 |
| 2 | Healthy Body Services Inc. | Caffeine 200 mg | 200 mg | 84.0 |
For information only; not medical advice. Talk to a doctor or pharmacist before starting or stopping any supplement.