Caffeine Consumption


Caffeine is undoubtedly one of the most popular beverages in the world. There are in fact reasons why you would love caffeine as well. We also observe a lot of addiction cases. However, there is a lot of research on how it affects sleep quality. And without a doubt, polyphasic sleep is no exception. 

Less total sleep duration also means more restrictions. As Puredoxyk once said in her book, you need to be aware of what you eat and drink. And it only makes sense that polyphasic sleepers should know more about caffeine consumption in this post. 

Caffeine Mechanics

Caffeine has a half-life of around 5-6 hours1. It will mostly be gone from the system after around 12-18 hours. However, it can still affect you depending on the initial amount consumed. It works by competing with adenosine for the same receptor type, which can reduce drowsiness. However, it also has some other effects, including increased heart rate2, increased sleep latency, and reduction in sleep quality3.

The increased sleep latency is particularly detrimental for polyphasic sleepers. For example, in one observed case, after consuming a moderate amount of coffee and caffeinated soda around 3 hours before sleeping, the sleep latency went through some negative changes. It then took half an hour to fall asleep and almost an hour to reach NREM2 as reported by an Olimex OpenEEG. It is worth noting that the experimenter was rather sleepy in the process. 

Caffeine Calculator

If you are interested in coffee’s effects and how it can affect you, check out this calculator.

Please note that the calculator is not an absolute determinant in your coffee use. Thus, it is better to err on the more cautious side.

Caffeine & Polyphasic Sleep

The general consensus within the polyphasic sleeping community is to completely remove caffeine. However, this likely will lead to withdrawal symptoms in long-term caffeine consumers. This is because the body responds to the constant caffeine supply by upregulating the adenosine receptor count4. Furthermore, a long-term tolerance and dependence is also a result of this process.

  • It may be favorable to first spend several weeks on regular (or even extended) sleep schedules to complete the withdrawal process.
  • Then, start an adaptation if you plan on removing it from your diet.

However, Puredoxyk mentions in her Ubersleep book that she took soda to stay awake during her initial Uberman adaptation. She also reportedly drank small amounts of coffee and other beverages while sleeping polyphasically. Thus, it may be advantageous in certain situations.

  • Small doses to offset sleep deprivation symptoms during an early period of adaptation or during the initial sleep deprivation period is possible.
  • One common trick is a “coffee nap” where you consume caffeine immediately before sleeping. However, this is normally not recommended; caffeine metabolism is fairly fast5 when consumed in liquid form. It may still boost performance under emergency situations, though. 
  • However, one can avoid this by using tablets. These generally have delayed onset. Due to its long half-life, future sleep sessions can be affected especially with small wake periods between each sleep. For this reason, coffee naps should be reserved for the most necessary situations.

Decaffeinated versions and similar drinks are not actually caffeine-free. The decaffeination process only removes between 70 and 86% of the caffeine in reality6.

Why coffee is normal with a lot of sleep
Caffeine on Segmented sleep

Caffeine consumption is overall acceptable on very few schedules, namely Segmented or other very extended schedules


Caffeine is present in several products; thus, restricting consumption of these to a certain degree is a good idea.

  1. Coffee (high content)
  2. Decaffeinated variants (low content)
  3. Black tea (moderate content)
  4. Green tea (low content)
  5. White tea (negligible content)
  6. Dark chocolate (high content)
  7. Milk chocolate (low content)
  8. Energy drinks (moderate content)
  9. Sodas (varying content), caffeine-free sodas include but are not limited to:
    • Diet coke
    • Sierra mist
    • Sprite
    • Seagram’s ginger ale
    • A&W root beer
    • 7-UP

A rough estimate of caffeine content per 100ml (or 100g):

  • negligible = 1 mg
  • small = 15-20 mg
  • moderate = 30-40 mg
  • large = >60 mg

Polyphasic sleepers should avoid even products with small amounts for the most part. They can still affect you if you consume in large amounts, or if you are sensitive to it. Nevertheless, the point after which it noticeably starts affecting you is highly individual. Some people have very low thresholds of under 10 mg, while others have very large thresholds of up to 600 mg7.

On the other hand, the positive effects wear out before the negative ones. This results in an energy low which increases oversleeping chance while still decreasing sleep quality.


In sum, polyphasic sleeping does not appear to go well with coffee. As usual, exceptions do exist, and you can experiment with it from time to time. Usually though, you may test its effects on your sleep after you have adapted to your schedule. In addition, the more sleep your schedule has, the more buffer it has to deal with these effects. 

Regardless, we still need more definitive research in the future to fully determine how it can be used on which polyphasic schedules. 

Main authors: Crimson & GeneralNguyen

Page last updated: 15 February 2021


  1. Statland B, Demas T. Serum caffeine half-lives. Healthy subjects vs. patients having alcoholic hepatic disease. Am J Clin Pathol. 1980;73(3):390-393. [PubMed]
  2. Geethavani G, Rameswarudu M, Rameshwari Reddy R. Effect of caffeine on heart rate and blood pressure. International Journal of Scientific and Research Publications. 2014;4(2):1-3.
  3. Březinová V. Effect of caffeine on sleep: EEG study in late middle age people. Br J Clin Pharmacol. 1974;1(3):203-208. [PubMed]
  4. Fredholm BB. Adenosine, Adenosine Receptors and the Actions of Caffeine. Pharmacology & Toxicology. 1995;76(2):93-101. doi:10.1111/j.1600-0773.1995.tb00111.x
  5. Caffeine Metabolism. Caffeine Informer. Published November 5, 2018. Accessed December 2, 2018.
  6. How is caffeine removed to produce decaffeinated coffee? Scientific American. Published 2018. Accessed October 21, 1999.
  7. Farag N, Vincent A, Sung B, Whitsett T, Wilson M, Lovallo W. Caffeine Tolerance is Incomplete: Persistent Blood Pressure Responses in the Ambulatory Setting. Am J Hypertens. 2005;18(5 Pt 1):714-719. [PubMed]