coffee

Brewed Coffee (240ml / 8oz)

Caffeine Half-Life Analysis

For: Smokers
95
mg Caffeine
3.0
Hour Half-Life
~N/A
Hours to Sleep-Safe
400
mg Daily Limit

trending_down Caffeine Decay Timeline

How 95mg caffeine clears from your system with a 3.0-hour half-life

Time Elapsed Caffeine Remaining % of Original Status
Now (consumption) 95.0 mg
100.0% 		Moderate
After 1 hour 75.4 mg
79.4% 		Moderate
After 2 hours 59.8 mg
63.0% 		Moderate
After 3 hours 47.5 mg
50.0% 		Minimal
After 4 hours 37.7 mg
39.7% 		Minimal
After 5 hours 29.9 mg
31.5% 		Minimal
After 6 hours 23.8 mg
25.0% 		Minimal
After 8 hours 15.0 mg
15.7% 		Minimal
After 10 hours 9.4 mg
9.9% 		Cleared
After 12 hours 5.9 mg
6.2% 		Cleared
After 16 hours 2.4 mg
2.5% 		Cleared
After 20 hours 0.9 mg
1.0% 		Cleared
After 24 hours 0.4 mg
0.4% 		Cleared

health_and_safety Health Insights for Smokers

⚠️ Important Health Consideration

Smoking induces CYP1A2 liver enzymes, which metabolize caffeine up to 50% faster. Smokers often need higher caffeine doses for the same effect.

Daily Limit Calculation

  • • Recommended daily limit: 400mg of caffeine
  • • Caffeine per serving: 95mg
  • • Servings until limit: 4.2 servings

While caffeine clears faster, the cardiovascular combination of nicotine and caffeine increases heart strain. Monitor total intake.

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 3.0 hours for smokers, caffeine follows exponential decay:

  • After 3.0 hours: 50% remains (47.5mg)
  • After 6.0 hours: 25% remains (23.75mg)
  • After 9.0 hours: 12.5% remains (11.875mg)
  • After 12.0 hours: 6.25% remains (5.9375mg)

The smokers category has a faster metabolism compared to healthy adults (5 hours baseline). Smoking induces CYP1A2 liver enzymes, which metabolize caffeine up to 50% faster. Smokers often need higher caffeine doses for the same effect.

warning Please Note

While caffeine clears faster, the cardiovascular combination of nicotine and caffeine increases heart strain. Monitor total intake.

Compare Other Drinks

Espresso (30ml / 1oz shot) 63mg Red Bull (250ml / 8.4oz) 80mg Monster Energy (473ml / 16oz) 160mg Green Tea (240ml / 8oz) 28mg

Compare Conditions

Healthy Adult 5.0h Pregnancy 10.5h Birth Control Users 7.5h Liver Impairment 12.0h Elderly (65+) 6.5h Fast Metabolizers (Genetic) 3.5h

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About Brewed Coffee (240ml / 8oz)

Standard drip-brewed coffee

Note: Caffeine can range from 70-140mg depending on brewing method and bean origin

help Frequently Asked Questions

How long does Brewed Coffee (240ml / 8oz) caffeine last for smokers?

For smokers, the caffeine half-life is approximately 3.0 hours. This means that 95mg of caffeine from Brewed Coffee (240ml / 8oz) will take about 3.0 hours to reduce to 48mg, and 6.0 hours to drop to 24mg. Full clearance (below 10mg) takes approximately 9.7 hours.

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

If you plan to sleep at 10 PM, you should consume your last Brewed Coffee (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 'Smokers' category affect caffeine metabolism?

Smoking induces CYP1A2 liver enzymes, which metabolize caffeine up to 50% faster. Smokers often need higher caffeine doses for the same effect. While caffeine clears faster, the cardiovascular combination of nicotine and caffeine increases heart strain. Monitor total intake.