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Red Bull (250ml / 8.4oz)

Caffeine Half-Life Analysis

For: Liver Impairment
80
mg Caffeine
12.0
Hour Half-Life
~N/A
Hours to Sleep-Safe
400
mg Daily Limit

trending_down Caffeine Decay Timeline

How 80mg caffeine clears from your system with a 12.0-hour half-life

Time Elapsed Caffeine Remaining % of Original Status
Now (consumption) 80.0 mg
100.0% 		Moderate
After 1 hour 75.5 mg
94.4% 		Moderate
After 2 hours 71.3 mg
89.1% 		Moderate
After 3 hours 67.3 mg
84.1% 		Moderate
After 4 hours 63.5 mg
79.4% 		Moderate
After 5 hours 59.9 mg
74.9% 		Moderate
After 6 hours 56.6 mg
70.7% 		Moderate
After 8 hours 50.4 mg
63.0% 		Moderate
After 10 hours 44.9 mg
56.1% 		Minimal
After 12 hours 40.0 mg
50.0% 		Minimal
After 16 hours 31.7 mg
39.7% 		Minimal
After 20 hours 25.2 mg
31.5% 		Minimal
After 24 hours 20.0 mg
25.0% 		Minimal

health_and_safety Health Insights for Liver Impairment

⚠️ Important Health Consideration

Conditions like cirrhosis or hepatitis reduce the liver's ability to produce CYP1A2 enzymes. Caffeine can remain in the system 2-3x longer than normal.

Daily Limit Calculation

  • • Recommended daily limit: 400mg of caffeine
  • • Caffeine per serving: 80mg
  • • Servings until limit: 5.0 servings

Consult your physician about caffeine intake. Consider limiting to 100mg/day or less.

Sleep Quality Impact

Caffeine blocks adenosine receptors in the brain, preventing the buildup of sleep pressure. Even when you don't feel "wired," residual caffeine can reduce deep sleep quality by up to 20%.

>100mg
May disrupt sleep
50-100mg
Reduced deep sleep
<50mg
Minimal impact

science How Caffeine Half-Life Works

Half-life is the time required for the body to eliminate 50% of a substance. For caffeine, this primarily occurs in the liver through the CYP1A2 enzyme system.

With a half-life of 12.0 hours for liver impairment, caffeine follows exponential decay:

  • After 12.0 hours: 50% remains (40.0mg)
  • After 24.0 hours: 25% remains (20.0mg)
  • After 36.0 hours: 12.5% remains (10.0mg)
  • After 48.0 hours: 6.25% remains (5.0mg)

The liver impairment category has a slower metabolism compared to healthy adults (5 hours baseline). Conditions like cirrhosis or hepatitis reduce the liver's ability to produce CYP1A2 enzymes. Caffeine can remain in the system 2-3x longer than normal.

warning Important Health Notice

Consult your physician about caffeine intake. Consider limiting to 100mg/day or less.

Compare Other Drinks

Brewed Coffee (240ml / 8oz) 95mg Espresso (30ml / 1oz shot) 63mg Monster Energy (473ml / 16oz) 160mg Green Tea (240ml / 8oz) 28mg

Compare Conditions

Healthy Adult 5.0h Smokers 3.0h Pregnancy 10.5h Birth Control Users 7.5h Elderly (65+) 6.5h Fast Metabolizers (Genetic) 3.5h

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About Red Bull (250ml / 8.4oz)

Popular energy drink

Note: Also contains taurine, B-vitamins, and 27g of sugar

help Frequently Asked Questions

How long does Red Bull (250ml / 8.4oz) caffeine last for liver impairment?

For liver impairment, the caffeine half-life is approximately 12.0 hours. This means that 80mg of caffeine from Red Bull (250ml / 8.4oz) will take about 12.0 hours to reduce to 40mg, and 24.0 hours to drop to 20mg. Full clearance (below 10mg) takes approximately 36.0 hours.

When should I stop drinking Red Bull (250ml / 8.4oz) to sleep well?

If you plan to sleep at 10 PM, you should consume your last Red Bull (250ml / 8.4oz) by any time - caffeine level is low. This allows approximately sufficient hours for caffeine levels to drop below the sleep disruption threshold of 100mg.

How does being in the 'Liver Impairment' category affect caffeine metabolism?

Conditions like cirrhosis or hepatitis reduce the liver's ability to produce CYP1A2 enzymes. Caffeine can remain in the system 2-3x longer than normal. Consult your physician about caffeine intake. Consider limiting to 100mg/day or less.