Caffeine is the most universally consumed stimulant of the central nervous system. It works primarily as an adenosine antagonist. Adenosine itself works as an inhibitory neurotransmitter that helps suppress activity in the central nervous system. Since caffeine is an antagonist for the adenosine receptors, it tends to speed up nervous system activity in a dose-related manner.

As a natural consequence of blocking the adenosine receptors, it can also influence the effects of other major neurotransmitters including acetylcholine, serotonin, and norepinephrine. It also has a smaller influence on cortisol, epinephrine, and glutamate production.  It has been shown to improve learning, memory, coordination, and overall cognitive performance. Most people consume caffeine to help them fully wake up and feel stimulated before the work day.

However, not everyone likes relying on a drug to help them get through the day. Although caffeine is one of the safest ways to “perk up” in the morning, some note that it can lead to long term dependency. For this reason, many people prefer to withdraw and take on life naturally – without the influence of drugs.

Factors that influence caffeine withdrawal include:

1. Individual physiology

Various physiological factors may impact your ability to withdraw from caffeine. For example someone that is naturally more mentally aroused may have an easier time withdrawing from caffeine than someone who is naturally underaroused. Additionally some people may not notice any withdrawal symptoms whereas others may notice many.

2. Frequency of use

How often do you drink caffeine can play a big role in determining the severity of your withdrawal. Do you drink caffeine on a daily basis? Do you drink it multiple times a day? Do you drink it all day every day? Obviously the more times you use caffeine throughout the day, the tougher it will be to withdraw from.

3. Amount of caffeine you drink

Caffeine amounts typically range from 16 mg to 160 mg. Coffee typically has about 135 mg of caffeine, whereas an energy drink may have up to 160 mg. Various types of tea typically have between 15 mg and 40 mg of caffeine. If you are pounding energy drinks on a daily basis, your body has likely become accustomed to high levels of caffeine.

This will make withdrawal more difficult as opposed to someone who only drinks white tea daily. In fact the person drinking white tea may not even note any withdrawal symptoms.

4. Dependency

Believe it or not, some people actually become dependent on caffeine for everyday functioning. Although it is a safe substance, the fact is that people use it for a mental crutch. It improves cognitive function and acts as a mental stimulant. Most people also notice improvement in energy levels and mood following ingestion of caffeine.

If you are dependent on caffeine for functioning in the workplace and/or it has become a staple towards helping you stay productive, withdrawal may be pretty difficult.

Common Caffeine Withdrawal Symptoms

Below are just some of the symptoms that you may experience while withdrawing from caffeine. Not everyone is going to experience all of these symptoms. You may only have a minor headache and feel a little sluggish before you bounce back to 100%. However, others may have a variety of symptoms that may make life difficult to deal with for a couple of weeks.

  • Anxiety: Although anxiety can be a response to drinking too much caffeine, some people can feel anxious while withdrawing. This has to do with the fact that the caffeine may have perked up their brain in social and performance-based situations. Now that they are coming off of the caffeine they feel anxious because they are not at the same level of performance as they were with caffeine.
  • Cravings: Many people experience cravings for caffeine. Although the addiction and abuse potential is low, some people have a difficult time kicking their coffee habit. It is common for you to physically and psychologically crave caffeine for a couple weeks into withdrawal. The craving alone should show you how certain people can become dependent on this substance for functioning.
  • Constipation: Since caffeine tends to stimulate bowel activity and movements, withdrawal may result in constipation. This tends to last a few days at the maximum and will eventually subside. Try to stay active and eat healthy to encourage normal bowels.
  • Depression: Since caffeine can produce a mood boost for some people, a natural consequence of withdrawal is a mild depression. You likely aren’t going to feel severely depressed, but you may notice that you feel sluggish, moody, and don’t feel like doing anything – this is normal and will subside.
  • Diarrhea: Some people note that they experience diarrhea when stopping caffeine – this is less common than constipation, but can be annoying to deal with.
  • Dizziness: It is common to feel somewhat dizzy when withdrawing from the consistent ingestion of high amounts of caffeine.
  • Flu-like symptoms: Some people report headaches, muscle pain, as well as vomiting. Obviously these can be minimized with gradual tapering of caffeine as opposed to “cold turkey” quitting. Typically only people that have become extremely dependent on caffeine will exhibit flu like symptoms.
  • Grogginess: Anyone that drinks caffeine can experience a “crash” and feel groggy. This will eventually go away as your body and brain recalibrate to life without caffeine.
  • Headache: Some people report standard headaches for the first few days of withdrawal, while others report experiencing migraines. This is your brain undergoing an adjustment – eventually this will go away. In the meantime take some Tylenol and wait a few days – the headaches will subside.
  • Insomnia: Although it is more likely that you will experience insomnia if you drink caffeine too close to bedtime, some people actually experience insomnia during withdrawal. I know this is counterintuitive, but withdrawing affects everyone differently.
  • Irritability: If caffeine gave you a slight mood boost or subtle feelings of happiness or perk, it is common to be irritable when withdrawing.
  • Lack of motivation: If you relied on caffeine to provide you with motivation, it’s going to be difficult getting through a few days or weeks in which you have zero motivation.
  • Lethargy: Most people end up feeling vey lethargic for a few days after quitting the use of caffeine. Some would say that this feeling is like a minor hangover.
  • Mood swings: Some people experience minor mood swings during their withdrawal period.
  • Muscle rigidity: You may notice that your muscles become tense and/or rigid. Again, this is another counterintuitive response that people have reported.
  • Nervousness: If caffeine helped perk you up to function in social situations, you may feel nervous as a result of slowed cognitive function.
  • Poor concentration: The inability to concentrate is very common. Caffeine is well known to enhance cognitive functioning so stopping it can negatively affect cognitive performance.
  • Shakiness: Some people get the shakes or feel shaky when stopping.
  • Sleepiness: The tiredness and sleepiness may be difficult to cope with, but it will eventually subside.
  • Slow thinking: Since caffeine acts as a stimulant and speeds up brain activity and functioning, not using it can result in slowed thinking. Eventually your brain will recover to its natural, homeostatic state. Fortunately the slow thinking here isn’t typically as severe as it would be during an Adderall crash.
  • Sluggish: It is very common to feel like a total slug for a few days when quitting caffeine.
  • Sweating: Some people may experience light sweats or even sweat profusely as their body gets reacclimated to functioning without caffeine.

Source: http://www.ncbi.nlm.nih.gov/pubmed/22341956

Note: After ceasing ingestion, the caffeine stays in your system for around 1.15 days after your last dose.  As a result, some people notice most symptoms emerge within 1-3 days of stopping.

How long do caffeine withdrawal symptoms last? Timeline can vary.

Most people suggest that the brunt of the physical symptoms such as bad headaches and constipation will go away within the first 48 hours of withdrawal. In other words, once a couple days have passed since you’ve ingested your last dose of caffeine, most of the physical symptoms should subside. However, if you were a chronic caffeine drinker, it is certainly plausible that they would last longer. In general, withdrawal for most people lasts between 7 and 14 days to fully recover.

It should be noted though that any substance that your body becomes dependent upon for everyday functioning may have an even longer withdrawal. There are cases of people experiencing withdrawal symptoms well after 2 weeks. Much of how severe your withdrawal will be depends on your individual physiology as well as other psychosocial factors. It also depends on whether you withdrew “cold turkey” or with a standard tapering method (e.g. gradually weaning off of it).

Although it may seem as though you are going crazy during withdrawal, you’re not. Caffeine withdrawal is extremely common. It may be an unpleasant experience, but it typically isn’t nearly as severe as other drugs or withdrawal from alcohol. Caffeine has a relatively low abuse potential and is considered a pretty safe substance. While you withdraw from caffeine, plan a few days to overcome the major symptoms such as on a weekend or vacation break so that most of them are not plaguing you the following week at work.