Matcha Green Tea Caffeine Half-Life & Bedtime Decay
Traditional matcha contains 70mg of caffeine per teaspoon of shade-grown green tea powder. Because matcha is made from ground whole leaves, it delivers high concentrations of L-theanine and EGCG catechins that smooth out the stimulant curve.
Interactive Stack Calculator for Matcha Green Tea
We've preloaded Matcha Green Tea (70mg) below. Adjust your planned bedtime or add other drinks to see your exact curve.
Caffeine Half-Life & Cutoff Calculator
Caffeine's half-life ranges from about 4 to 7 hours depending on how fast you metabolise it. Add what you've already drunk today to find the last time your next drink still leaves under 50 mg in your system at bedtime.
Caffeine Sensitivity
Not sure? If an afternoon coffee keeps you up at night, pick Slow.
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Last safe 70 mg drink
Calculated so that under 50 mg of caffeine is still circulating at bedtime, counting today's drinks.
Today's drinks alone leave about 11 mg at bedtime.
Solid: caffeine from today's drinks. Dashed: with one more drink at your cutoff, landing on the 50 mg line at bedtime.
Stop guessing your cutoff.
Here you type your drinks in. ARC does the same math from every drink you log in one tap, moves your last safe coffee the moment you log a cup, shows it as a live countdown, and tells you plainly when no cup fits any more.
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Matcha Green Tea Hour-by-Hour Caffeine Decay Table
Pharmacokinetic Decay (5.5h Half-Life)Exact milligrams of caffeine remaining in the bloodstream at 2-hour intervals if consumed at various times of day, based on an average human caffeine half-life of 5.5 hours. Target is less than 50mg active at 11:00 PM bedtime.
| Intake Time | +2 hrs | +4 hrs | +6 hrs | +8 hrs | +10 hrs | +12 hrs | At 11 PM Bed | Status |
|---|---|---|---|---|---|---|---|---|
| 08:00 AM | 54 mg | 42 mg | 33 mg | 26 mg | 20 mg | 15 mg | 11 mg | ✓ Sleep Safe |
| 12:00 PM (Noon) | 54 mg | 42 mg | 33 mg | 26 mg | 20 mg | 15 mg | 18 mg | ✓ Sleep Safe |
| 02:00 PM | 54 mg | 42 mg | 33 mg | 26 mg | 20 mg | 15 mg | 23 mg | ✓ Sleep Safe |
| 04:00 PM | 54 mg | 42 mg | 33 mg | 26 mg | 20 mg | 15 mg | 29 mg | ✓ Sleep Safe |
Cutoff Recommendation: Safe to consume up until 4:30 PM for an 11:00 PM bedtime for average metabolisers.
Values are calculated using the standard exponential decay model: mg_remaining = initial_mg * 0.5^(hours / half_life).
How Your Genetics (CYP1A2) Impact Matcha Green Tea Clearance
Over 95% of caffeine metabolism takes place in your liver via the cytochrome P450 enzyme CYP1A2. Depending on whether you carry the fast or slow metabolizing gene variant, clearance times for 70mg vary drastically:
Residual after 8 hours: 18 mg. You clear caffeine rapidly and rarely experience insomnia from lunch beverages.
Residual after 8 hours: 26 mg. Standard biological decay rate representing ~50% of the population.
Residual after 8 hours: 32 mg. CYP1A2*1F carriers. Any caffeine consumed past noon will disrupt sleep architecture.
Frequently asked questions
Why does matcha feel calmer than coffee?
Matcha contains L-theanine (approx. 20–30mg per bowl), an amino acid that crosses the blood-brain barrier to stimulate GABA production and alpha brain waves, preventing jitters and heart palpitations.
Can matcha disrupt sleep?
Yes, if consumed within 4 hours of bedtime. Although calmer, its 70mg of caffeine still blocks adenosine receptors and can fragment REM sleep if circulating above 50mg.