Unbuzz is a free iOS app that helps you quit caffeine: it models the caffeine actually in your blood using a half-life personalized to you, shows you the live decay curve, and lets you step your daily intake down gradually so you never hit the withdrawal headache. Most people who taper reach zero, or a level that no longer hurts their sleep, in 2 to 4 weeks.
Quit caffeine with a curve, not willpower. Unbuzz is free on the App Store.
Why Quitting Caffeine Cold Turkey Backfires
If you drink caffeine daily, your brain has adapted: it grows extra adenosine receptors to push back against the constant blockade. Take the caffeine away overnight and all of that unopposed adenosine hits at once. The result is a recognized withdrawal syndrome: headache, fatigue, irritability, and trouble concentrating that typically start 12 to 24 hours after your last dose and peak at 24 to 48 hours. That second day is where most quit attempts die.
None of this means you are weak. It means the dose dropped faster than your receptors could downregulate. The fix is mechanical, not motivational: lower the dose slower than the adaptation reverses. The full symptom timeline is in the caffeine withdrawal guide.
The Science You Are Working With
Two numbers drive the whole project:
- The 5-hour half-life. Caffeine clears by exponential decay with a median half-life of about 5 hours. A 200 mg afternoon coffee is still roughly 100 mg in your blood 5 hours later and 50 mg after 10. Your personal half-life can sit anywhere from about 2 to 12 hours depending on CYP1A2 genetics, smoking, pregnancy, and medications, which is why two people on identical intakes sleep completely differently.
- The 50 mg sleep threshold. Below roughly 50 mg of circulating caffeine, the alerting effect fades for most people. Keeping your bedtime residual under that line is the single highest-value change, and it often matters more than total daily intake.
You can see both numbers in action on the caffeine half-life calculator: enter a drink and a bedtime and it shows when you are sleep-ready, hour by hour.
The Taper That Actually Works
The sequence matters. Cutting the morning coffee first feels virtuous and accomplishes the least; the evening doses are what wreck sleep, and bad sleep is what drives the next day's overconsumption.
- Week 0: measure, change nothing. Log every caffeine source for 2 to 3 days, including soda, tea, chocolate, pre-workout, and pain relievers. Most people undercount by a wide margin. You cannot taper a number you do not know.
- Week 1: move the cutoff, keep the dose. Keep drinking the same amount, but finish your last dose early enough that under 50 mg remains at bedtime (for many people that is 8 to 10 hours before bed; the sleep cutoff tables have drink-by-drink times). Better sleep makes the next steps far easier.
- Weeks 2 to 3: step down about 25% every 3 to 4 days. Swap, do not skip: replace one coffee with a green tea (about a quarter of the caffeine), then half-caf, then decaf, which still carries a small dose that softens the landing. Each step is small enough that withdrawal stays below the symptom threshold.
- Hold at your target. Zero is one valid target. Under 100 mg before noon is another. If tolerance was your real complaint, hold the low level for 2 to 3 weeks and caffeine will work again when you want it to; see the caffeine reset guide.
The day-by-day version of this schedule, including the relapse plan, is in the 21-day cut-back guide.
Where an App Actually Helps (and Where It Cannot)
An honest pitch: no app removes withdrawal. What a good one does is replace guesswork with numbers at the four moments that decide whether a taper survives:
- Knowing your real baseline. Unbuzz logs any drink in a couple of taps, with a database of caffeine contents, so week 0 takes no discipline.
- Seeing the curve, not the cup count. The app shows milligrams currently in your blood, decaying in real time on a half-life adjusted to you (smoking, pregnancy, contraceptives, and sensitivity all shift it). The 2 PM "just one more" decision looks different when you can see it landing on top of 120 mg you still carry.
- A sleep-ready time, every day. Instead of a generic cutoff rule, Unbuzz predicts the moment your residual drops under the threshold before your actual bedtime, and warns you when a drink would push past it.
- Proof the taper is working. A falling weekly average is the feedback loop that keeps the project alive through the flat days when you cannot feel progress yet.
What it will not do: cure the day-2 headache if you quit cold turkey, replace medical advice, or work on Android yet (Unbuzz is currently iOS only). If you want to compare alternatives first, the caffeine tracker app guide lays out the evaluation criteria we would use against ourselves.
What to Expect, Week by Week
| Phase | What happens | What to do |
|---|---|---|
| Week 0 | You discover your real intake; it is usually higher than you guessed. | Log everything, change nothing. |
| Week 1 | Sleep starts improving from the earlier cutoff alone, often within 3 to 4 nights. | Same dose, earlier last call. |
| Weeks 2 to 3 | Dose steps down 25% at a time; mild dips in energy for a day or two per step are normal, a pounding headache is not (step was too big). | Swap drinks down the caffeine ladder; hold a step longer if needed. |
| Week 4+ | At zero or your target. Morning grogginess lifts as adenosine signaling normalizes; caffeine sensitivity is restored if you reintroduce it. | Keep the bedtime threshold rule forever; it is the part worth keeping. |
