C4 Smart Energy Caffeine Half-Life & Bedtime Decay
Formulated with 200mg of InnovaTea natural caffeine derived from fermented tea leaves, paired with Cognizin citicoline for cognitive focus without beta-alanine tingles.
Interactive Stack Calculator for C4 Smart Energy
We've preloaded C4 Smart Energy (200mg) 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.
Pick your next drink
Last safe 200 mg drink
For this drink size, the safe window closed earlier today. A smaller drink, or decaf, may still fit.
Today's drinks alone leave about 30 mg at bedtime.
Solid: caffeine from today's drinks.
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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<iframe src="https://arcapp.sbs/tools/caffeine-calculator" width="100%" height="600px" frameborder="0"></iframe> <p>Caffeine calculator by <a href="https://arcapp.sbs/tools/caffeine-calculator">ARC</a></p>
C4 Smart Energy 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 | 155 mg | 121 mg | 94 mg | 73 mg | 57 mg | 44 mg | 30 mg | ✓ Sleep Safe |
| 12:00 PM (Noon) | 155 mg | 121 mg | 94 mg | 73 mg | 57 mg | 44 mg | 50 mg | ✓ Sleep Safe |
| 02:00 PM | 155 mg | 121 mg | 94 mg | 73 mg | 57 mg | 44 mg | 64 mg | ✕ Above 50mg |
| 04:00 PM | 155 mg | 121 mg | 94 mg | 73 mg | 57 mg | 44 mg | 83 mg | ✕ Above 50mg |
Cutoff Recommendation: Safe cutoff is 1:30 PM for standard 11:00 PM sleep schedules.
Values are calculated using the standard exponential decay model: mg_remaining = initial_mg * 0.5^(hours / half_life).
How Your Genetics (CYP1A2) Impact C4 Smart Energy 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 200mg vary drastically:
Residual after 8 hours: 50 mg. You clear caffeine rapidly and rarely experience insomnia from lunch beverages.
Residual after 8 hours: 73 mg. Standard biological decay rate representing ~50% of the population.
Residual after 8 hours: 91 mg. CYP1A2*1F carriers. Any caffeine consumed past noon will disrupt sleep architecture.
Frequently asked questions
Does C4 Smart Energy clear faster than regular C4?
No. Natural caffeine and synthetic caffeine have identical molecular structures (1,3,7-trimethylxanthine) and are cleared by hepatic CYP1A2 enzymes at the exact same rate.