emoji_food_beverage

Green Tea (240ml / 8oz)

Caffeine Half-Life Analysis

For: Liver Impairment
28
mg Caffeine
12.0
Hour Half-Life
~N/A
Hours to Sleep-Safe
400
mg Daily Limit

trending_down Caffeine Decay Timeline

How 28mg caffeine clears from your system with a 12.0-hour half-life

Time Elapsed Caffeine Remaining % of Original Status
Now (consumption) 28.0 mg
100.0% 		Minimal
After 1 hour 26.4 mg
94.4% 		Minimal
After 2 hours 24.9 mg
89.1% 		Minimal
After 3 hours 23.5 mg
84.1% 		Minimal
After 4 hours 22.2 mg
79.4% 		Minimal
After 5 hours 21.0 mg
74.9% 		Minimal
After 6 hours 19.8 mg
70.7% 		Minimal
After 8 hours 17.6 mg
63.0% 		Minimal
After 10 hours 15.7 mg
56.1% 		Minimal
After 12 hours 14.0 mg
50.0% 		Minimal
After 16 hours 11.1 mg
39.7% 		Minimal
After 20 hours 8.8 mg
31.5% 		Cleared
After 24 hours 7.0 mg
25.0% 		Cleared

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: 28mg
  • • Servings until limit: 14.3 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 (14.0mg)
  • After 24.0 hours: 25% remains (7.0mg)
  • After 36.0 hours: 12.5% remains (3.5mg)
  • After 48.0 hours: 6.25% remains (1.75mg)

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 Red Bull (250ml / 8.4oz) 80mg Monster Energy (473ml / 16oz) 160mg

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

Related Tools

local_cafe Full Caffeine Calculator hourglass_bottom Caffeine Cut-off Time bedtime Sleep Cycle Calculator

About Green Tea (240ml / 8oz)

Brewed green tea

Note: Contains L-theanine which modulates caffeine's effects

help Frequently Asked Questions

How long does Green Tea (240ml / 8oz) caffeine last for liver impairment?

For liver impairment, the caffeine half-life is approximately 12.0 hours. This means that 28mg of caffeine from Green Tea (240ml / 8oz) will take about 12.0 hours to reduce to 14mg, and 24.0 hours to drop to 7mg. Full clearance (below 10mg) takes approximately 17.8 hours.

When should I stop drinking Green Tea (240ml / 8oz) to sleep well?

If you plan to sleep at 10 PM, you should consume your last Green Tea (240ml / 8oz) 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.