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The Focus Log
Practical, sourced answers on focus, energy, and staying sharp — no hype, no crash.
Caffeine Crash: What Causes It and How to Avoid It
Most of what people call a caffeine crash is tiredness the caffeine was covering, plus withdrawal, short sleep or sugar. Here's what the studies...
ReadHow Long Does Caffeine Stay in Your System? What the Studies Show
Caffeine's half-life is about 3 to 6 hours in healthy adults, but individuals range from 2 to 10 hours. Here is what changes it...
ReadCaffeine and L-Theanine: What the Studies Show and How Much to Take
The best-studied range is 97-250 mg L-theanine with 40-150 mg caffeine. Here is what four primary sources found, and what they did not.
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