Caffeine Metabolism Tracker
Scientific analysis of how your body clears caffeine based on genetics, smoking, and medication.
- Section
- Health & Vitality
- Reviewed
- Your data
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Caffeine Doses
Personal Factors
Fast = CYP1A2 *1F variant. Slow = *1A variant (most common).
Results
Half-Life
5.5h
Total Load
200mg
Time to Clear
24h
Status
Safe
Safety threshold (6mg/kg)420mg
Caffeine Level Over Time
8h
·
10h
·
12h
·
14h
·
16h
·
18h
·
20h
·
22h
Active caffeine (mg) by hour — includes all doses
Method and basis
How the figure above is derived, and when not to act on it.
The Caffeine half-life logic
Caffeine has an average half-life of 5 hours, but this is highly variable.- Smokers: Clear caffeine ~50% faster.
- Birth Control: Can double the half-life.
- Pregnancy: Can triple the half-life in the third trimester.
WinSport Editorial & Research Standards
All formulas and reference values used in this tool are sourced from peer-reviewed scientific literature and validated clinical guidelines. Our research team continuously audits each calculator for accuracy and updates methodology as new evidence emerges.
Read the Science
Sports Science Articles- Two Athletes. Identical Caffeine Protocol. Completely Different Results. Here's Why.Caffeine half-life ranges from 1.5 to 9.5 hours in the general population — driven almost entirely by a single genetic variant. Most caffeine protocols are built as if this variability doesn't exist.5 min read
- You've Been Using Caffeine Wrong Before Your A-Race — The Sensitivity Reset ProtocolRegular caffeine users blunt their own ergogenic advantage. A structured pre-competition washout protocol restores adenosine receptor sensitivity — maximising race-day caffeine effect.5 min read
- The 200mg Caffeine Limit in Pregnancy Is Evidence-Based. The Reasoning Behind It Is More Important Than the Number.Pregnancy suppresses CYP1A2 to 30% of baseline by the third trimester, extending caffeine half-life to 10-18 hours. The WHO 200mg daily limit is well-founded, but the pharmacokinetics explain why timing matters as much as dose.5 min read
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