A 22-year-old member asked:
How long does caffeine stay in your system?
4 doctor answers • 9 doctors weighed in
Specializes in Family Medicine
Depends: Depends on size and age of the person, and what else is in the system, but the half life is 3 to 12 hours.
6.1k viewsReviewed >2 years ago
Addiction Medicine 41 years experience
Depends on dose: The more caffeine you drink, the higher the initial level. After4-6 hours your level will drop. Some of us are more sensitive, and after one cup of coffee will have effects for more than 12 hours.
6k viewsReviewed >2 years ago
A Verified Doctoranswered
Variable: In general, it is short-acting, with a half-life of about 3 hours, but there may be genetic differences as well as drug/drug and drug/food interactions. Some people are very sensitive to some effects of caffeine, and consuming some in the morning may even interfere with sleep. Drugs like caffeine alter the receptor/neurotransmitter environment, and those effects may last longer than the drug.
5.5k viewsAnswered >2 years agoMerged
Anesthesiology 25 years experience
A long time...: It stays in your body longer than you might think. Half life of caffeine can be anywhere from three to seven hours which means it can stay in your system 5 times that long depending on your metabolism.
1.9k viewsAnswered >2 years agoMerged
A 24-year-old female asked:
How long does caffeine from a can of soda stay in your system?
1 doctor answer • 2 doctors weighed in
Pharmacology 17 years experience
Caffeine: A caffeine peak occurs approximately 2 hours after ingestion. The biological half-life of caffeine is about 5 hours. This means that the caffeine should be cleared in approximately 25 hours.
5.7k viewsReviewed >2 years ago
Mt Sinai, NY
A 28-year-old male asked:
How long does it take caffeine to get out of your system?
1 doctor answer • 1 doctor weighed in
Pathology 49 years experience
Variable: Usual half life of caffeine is 3-7 hours. It takes about 10 half lives for the chemical to become undetectable. Use of tobacco, birth control pills, pregnancy and some medications prolong the clearance time.
2.4k viewsAnswered >2 years ago
Last updated Feb 19, 2020
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