To be under 50 mg of residual caffeine at an 11 PM bedtime, have your last 250 ml can of V Energy Drink (78 mg) by 7:45 PM (19:45). The math uses the median 5-hour caffeine half-life; individual half-lives range from about 2 to 12 hours.
V Energy Drink Last-Call Times by Bedtime
Latest time to finish a 250 ml can of V Energy Drink (78 mg of caffeine) and still be under 50 mg of residual caffeine at bedtime, assuming the median 5-hour half-life. Your personal half-life may sit anywhere in the 2 to 12 hour range.
| Bedtime | Last call for V Energy Drink | Residual at bedtime |
|---|---|---|
| 9:00 PM (21:00) | 5:45 PM (17:45) | ~50 mg |
| 10:00 PM (22:00) | 6:45 PM (18:45) | ~50 mg |
| 11:00 PM (23:00) | 7:45 PM (19:45) | ~50 mg |
| 12:00 AM (00:00, midnight) | 8:45 PM (20:45) | ~50 mg |
Clearance Time by Serving Size
How long each serving of V Energy Drink needs before bed to drop under 50 mg:
| Serving | Caffeine | Time needed before bed |
|---|---|---|
| 250 ml can | 78 mg | 3 h 13 min |
| 500 ml can | 155 mg | 8 h 10 min |
Source: caffeine figures from Caffeine Informer, accessed 2026-06-11. Values can vary by batch, location, and preparation; check the label or the source for the latest figures.
How the Math Works
Caffeine leaves your body by exponential decay. With the median 5-hour half-life, the 78 mg in a 250 ml can of V Energy Drink falls to 39 mg after 5 hours and 20 mg after 10 hours. To get under 50 mg, the level where caffeine stops measurably delaying sleep for most people, it needs about 3 h 13 min of clearance time. Subtract that from your bedtime and you get the last-call times above, rounded down to the nearest 15 minutes.
The big caveat: the 5-hour figure is a median. Depending on CYP1A2 genetics, medications, smoking, and pregnancy, real half-lives run from about 2 to 12 hours. If caffeine reliably keeps you up, treat these times as too generous and move your personal cutoff earlier, or model your own curve in the caffeine half-life calculator.