T Nation

Caffeine Takes 3-4 Hours?


#1

is there any truth to the statement "caffeine takes 3-4 hours to effect the system"?

someone told me they learned it from their physiology class or something.

i said there is no way but i would get to my experts and report back. thanks guys.


#2

I'd be surprised because whenever I take a caffeine supplement I feel it within minutes.

Maybe it's a placebo effect?


#3

No, it happens much faster than that for most people. It'd be more accurate to say it starts having an effect at about 30 minutes (depending a little on digestion rates) and reaches full effect in a couple hours.

It also depends on whether or not you start exercising after ingesting it - if you get blood flowing around faster it'll take effect a bit faster.

-Dan


#4

3-4 hours to LEAVE the system. If it took 3-4 hours to effect the human body, Red Bull would be out of business and there would be no addiction in this country to "Morning coffee".


#5

And my husband would never get out of bed.


#6

You're referring to caffeine's effects on metabolizing free fatty acids.

The CNS stimulating effects are obviously much quicker.


#7

Maybe you heard that caffeine takes 3 - 4 hours (or more) to be cleared from your system - which is why it's not a great idea to take caffeine in the late afternoon if you're sensitive to it or tend to have trouble sleeping.


#8

The initial response or onset occurs within 15-45 minutes in healthy adults.

Peak plasma concentrations are reached around 30-36 minutes on average.

The elimination half-life is 4-5 hours, the variance depending upon the dose given.


#9

most of us have likely taken caffeine, so when he made that bold statement i griningly asked him if he was stating that the initial effects were placebo. he stuck to his statement so i told him i would find out if there was any truth to it in a few days.

thanks T-Nation.

thanks Cy.


#10

Not to mention a whole lot of "supplement manufacturers" who have hung their collective hats on caffeine being a key ingredient in "fat burning."