Caffeine/Summary

Main article: Caffeine

Psychoactive class: Stimulants

Chemical class: Xanthines

Oral

• Thresh				Common				Heavy
  25	-	25	-	50	-	150	-	500	mg
  		Light				Strong

• • Total: 2 - 5 hours
  • Onset: 5 - 10 minutes
  • Come up: 15 - 60 minutes
  • Peak: 30 - 120 minutes
  • Offset: 70 - 120 minutes
  • Afterglow: 3 - 6 hours

Insufflated

• Thresh				Common				Heavy
  2.5	-	10	-	25	-	40	-	80	mg
  		Light				Strong

• • Total: 1 - 2.5 hours
  • Onset: 0.5 - 2 minutes
  • Come up: 0.5 - 2 minutes
  • Peak: 0.5 - 1 hours
  • Offset: 6 - 10 hours
  • Afterglow: 6 - 24 hours

Smoked

• Thresh				Common				Heavy
  25	-	25	-	50	-	125	-	175	mg
  		Light				Strong

• • Total: 45 - 70 minutes
  • Onset: 2 - 5 minutes
  • Peak: 10 - 20 minutes
  • Offset: 30 - 45 minutes
  • Afterglow: 2 - 4 hours

Harm potential

• • The LD50 of caffeine in humans is dependent on individual sensitivity, but is estimated to be about 150 to 200 milligrams per kilogram of body mass or roughly 80 to 100 cups of coffee for an average adult

Tolerance

• • Full tolerance is reached develops with prolonged and repeated use
  • Decreases to half after 3 - 7 days
  • Returns to baseline after 1 - 2 weeks
  • Cross-tolerance with antagonists adenosine receptors

Physical effects

• • Stimulation
• • Appetite suppression
• • Dizziness
  • Frequent urination
  • Headache
  • Increased blood pressure
  • Increased heart rate
  • Increased perspiration
  • Nausea
  • Teeth grinding
  • Vasoconstriction

Cognitive effects

• • Cognitive dysphoria
  • Cognitive euphoria
  • Compulsive redosing
• • Analysis enhancement
  • Increased libido
  • Increased music appreciation
  • Memory enhancement
  • Motivation enhancement
• • Thought deceleration

See also

• Responsible use
• Summary index
• Subjective effect index
• Psychoactive substance index