Caffeine Absorption


How Quickly Does Caffeine Enter The Bloodstream?

Those that are regular consumers of coffee or energy drinks have figured out that it takes about 15-20 minutes before the effects of caffeine are realized.

Energy shots can be a tad quicker since there is less liquid to drink and food items such as caffeinated gum or chews can be even quicker since some of the caffeine is absorbed through the lining of the mouth.

However, feeling alert doesn’t really tell us how long it takes for all of the caffeine to be fully absorbed into the bloodstream. This is a bit more complicated.

Luckily, there have been a few scientific studies that have measured how fast caffeine via different mediums is completely absorbed by the bloodstream.

Caffeine Absorption Rates

Caffeine MediumAmountBioavailabilityBlood Saturation
Caffeine Capsules¹200mg90%84-120 minutes
Caffeine Gum¹200mg77%44-80 minutes
Coffee²200mg99%42-39 minutes
Energy Drink²200mg99%42-39 minutes

Looking at the above data, we can glean some interesting information. 

  1. Liquid is the overall best caffeine delivery method with the most caffeine being absorbed in the least amount of time to fully saturate blood plasma.
  2. The effects of caffeine gum are quicker, but less caffeine is absorbed overall. An advertised 100mg caffeine piece of gum would really only deliver 77mg of caffeine.
  3. Caffeine capsules and tablets take the longest to fully saturate the blood since they have to dissolve in the stomach first.

We couldn’t locate any data on caffeine candies such as LiveWire Chews or Jelly Belly Extreme Sports Beans, but since these items are completely dissolved by the saliva and swallowed, they would most likely have similar results as the liquid caffeine delivery agents.

As for caffeinated gum, our guess would be that caffeine gum has less bioavailability because some of the caffeine gets trapped in the gum material, which is not fully consumed.

Is Caffeine on an Empty Stomach Best?

Many people report that drinking caffeine on an empty stomach provides faster absorption than drinking caffeine with food or after eating.

There was some research³ into this notion and it found that the rate of stomach emptying did speed up or slow down blood saturation rates. People with full stomachs, especially those given a high fiber (hard to digest) meal had slower caffeine absorption rates.

Some people report consuming caffeine on an empty stomach causes indigestion.

Different Times Call For Different Caffeine

Caffeine absorption isn’t as straight forward as people might think since there are several variables that influence how quickly it saturates the bloodstream. While there are many ways to consume caffeine, the best way may depend on the situation a people find themselves in.

If a person needs to feel the effects of caffeine quicker, gum or candy would be in order. But, if a person wants to get the most bang for their buck, then caffeine in liquid form will deliver the exact dose they had hoped for.

This article only covers caffeine absorption, so If you also want to learn about caffeine metabolism look here and see this article for information about the half life of caffeine. 

2. Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations ( 2001 )

Get Help Quitting Caffeine

Reduce your caffeine intake without pain and discomfort.

See our new 10-step plan
  • Good idea! I’ll look into this.

  • Ty

    So, what about products like this?

    They still have to digest/dissolve in the stomach so does the “rapid” effect just placebo?

  • I would guess they they fit in the time line of capsules mentioned above. These could be designed to dissolve faster than others though.

  • joe


  • joe


  • joe


  • Poppy

    If you had an existing heart problem moderate- severe though, that would have killed you by now. Also, you should probably cut down, that can’t be good for you

  • Victoria

    Helpful! Really tidy and nice article. Will keep reading what you guys post 🙂

  • Ted

    Thanks Victoria, we appreciate your feedback.

  • Troy Gardner

    because the amount of water dilutes the effect and slows the absorption rate. Say you have equal 200mg of caffiene in both, but one is 1/2 as dense, will drive faster through the intestinal wall as it’s partly driven by the concentration balance/difference on opposing sides of mouth or intestinal tissue, and it has to reach a certain threshold in a certain time for it to work best. Like any drug, there is optimal dose for optimal effect that varies on person, it might be something like this as seen in the blood

    50mg – low almost no effect
    100mg – ok effect — minimal threshold
    150mg – optimal dose
    200mg – a little too much (tad bit of sweating, faster speech)
    250mg – overdose (anxiety, sweating profusely, heart racing)

    If you had 200mg with food, the digestion might deliver that over 2 hours, so you might not even get 50mg in the blood. if you took it on an empty stomach you might get 150mg in 10 minutes, which is enough to be felt.

  • artman99

    Source 2 measured time to peak saliva levels not blood saturation. And it matters – they measured time to peak saliva level for a pill and it was 67 minutes which is a lot less than the 84-120 min you found in source 1. It’s unlikely that time to peak for anything you drink is lower than sublingual or gum times to peak. Drinking coffee is slower, but yes faster than the pill.

  • artman99

    Generally when I take sublingual pills ive heard them say no water for a few minutes. Under the tongue big blood vessels and you wantthehighest concentration of med sitting there as long as good contact. Def crushed up and only a little saliva fastest. Stick a sonic toothbrush under there and you get half the rush of snorting something.

  • lol


  • What about chocolate? The caffeine in chocolate candy is in the fat that is cocoa butter. Since fat coats the mouth and tongue better than water, is the caffeine in chocolate absorbed faster and better?

  • Ted

    Chocolate has little caffeine and it’s actually in the cocoa solids. But, as for absorption, I doubt there has been any studies on chocolate since it’s really not a primary caffeine source. People eat chocolate primarily for the taste and the theobromine.

  • My question remains. People make similar claims for the “taste” of both coffee and tobacco. We eat chocolate because it is a stimulant, exactly like coffee and tobacco. The taste of these substances is only related to their qualities as a delivery system and the quantity of the drug delivered.

  • Martin Mews

    What about nappies? Taking a cue from the nicotine patch crowd I’ve been wearing disposable caffinated nappies for the last month or two (changed daily) and I’m pleased to report I feel great and totally absorbed all day long.

  • Pingback: How To Hack Your Mornings - IAmTye()

  • Elias Fierens


  • ThePrufessa

    i have never in my life ate chocolate for it’s stimulant properties.

    furthermore, i have never noticed the stimulant properties of chocolate after consuming it. not even when i overdo my chocolate intake (which happens from time to time when i get a hold of a bag of chocolates).

    even furthermore, i have never heard of anyone saying that they need some chocolate in order to wake up or feel less sleepy.

    so what in the world are you talking about? there’s very little caffeine found in chocolate relatively speaking. it’s miniscule and not worth doing this experiment on.

Last Modified: September 11, 2014