This guide covers specific caffeine dosages for different goals, then provides tools for you to find your perfect caffeine dosage schedule.
Skip ahead to the caffeine dosage algorithm if you’re not interested in the goals and just want to optimize your caffeine supplementation.
Taking Caffeine for Different Goals
Caffeine’s primary benefit is simple: it provides energy. However, your chosen goal changes the best way to supplement caffeine through dosage and timing.
Caffeine for Motivation
Caffeine is a staple ingredient for most pre-workout supplement blends. One ingredient that pairs well with caffeine is NALT.
If you already take a pre-workout with caffeine, you may notice your motivation suffering without it. Many pre-workouts, like Cellucor C4, have ingredients which affect dopamine (mucuna pruriens in C4’s case). Caffeine, especially when it’s stacked with a dopamine precursor, like NALT, increases motivation.
If you don’t feel like working out (maybe it’s leg day), then this caffeine + dopamine precursor combo will help you power through.
How Much to Take
For a boost of motivation, anywhere from 50 mg to 200 mg of caffeine may be optimal. Start with 50 mg and increase if needed.
Be sure to pair this with a supplement that promotes dopamine levels: 350 mg of NALT for a sharper increase or 250 mg of uridine monophosphate for a more gradual, sustained motivation.
When to Take
If taken on an empty stomach, caffeine usually kicks in within 15 minutes and energy peaks within the first hour.
Caffeine for Weight Loss
This only works if you are not caffeine tolerant. Caffeine increases metabolism initially, but its effectiveness diminishes if you take caffeine regularly. If you’re already taking caffeine, then lowering your caffeine tolerance is crucial.
How to Counter Caffeine Tolerance
If weight loss is your goal, take caffeine for one to two weeks, and then take two weeks off. This two-week resting period is based on the time it takes for tolerance to wear off.
If you are dependent on caffeine and find it difficult to quit, then taper off usage. See the Quitting Caffeine section for the guide.
How Much to Take
100 mg to 400 mg daily is recommended for weight loss. Do not exceed 400 mg per day or 200 mg per dose.
If you’re drinking coffee, be sure not to use sugar or cream as this is counterproductive in reducing your caloric intake and losing weight.
Keep in Mind
Caffeine is only a supplemental aid for weight loss. Gradual caloric reduction and cardio are vital for losing weight.
When Caffeine is Counterproductive to Weight Loss
If caffeine keeps you up at night and you sleep less, your hunger increases the next day. This is due to your body producing more ghrelin, the hunger hormone, when in a sleep deprived state (source).
If your sleep quality is suffering due to caffeine, ensure your last caffeine dose is at least 8 hours before bedtime. Or try a supplement that reduces the level of caffeine in your system like NAC.
Taking caffeine is often necessary in order to quit caffeine. Why? Quitting caffeine cold turkey is miserable and unnecessary.
The key is to taper off caffeine using incrementally smaller doses over time. You can choose your own pace, whether it’s one week or two months.
Calculate your Dosage Reduction
Take your current daily dosage and divide it by the number of days or weeks in your quitting phase. Then reduce your daily or weekly dosage by this number.
Let’s say you want to quit caffeine in 2 weeks and your current daily dosage is 700 mg:
Daily caffeine reduction = current dosage / days in quitting phase
700 mg / 14 days = 50 mg
So each day, you reduce your caffeine intake by 50 mg: 650 mg on day 1, 600 mg on day 2, and so on. Then by day 14, you arrive at 0 mg.
Roadblock: Caffeine Powder is Unavailable
Measuring your reduced dosage is easy with caffeine powder. However, due to overdoses caused by measuring errors, your options to purchase caffeine in powder format are limited.
This leaves you with two choices:
Pay an outrageous price for a caffeine quitting product. These are small dosage capsules (usually 20 mg of caffeine per capsule). You take ‘x’ number of capsules each day in decrementing amounts.
Or buy a pill splitter for a few dollars and divide your 200 mg caffeine tablets into four parts. If your caffeine reduction dosage is closer to 25 mg then divide each part once more.
If coffee is your thing, then reduce your daily ounces of coffee using the same method. And keep in mind that decaf coffee still has 2-12 mg of caffeine per cup.
Caffeine for Workouts
Caffeine is in most pre-workout supplements, and there’s good reason for this. Caffeine not only improves power output and endurance, but it also delays fatigue.
To understand this, let’s talk about adenosine. This chemical is found naturally in your body and causes fatigue by accumulating around adrenergic receptors, which are responsible for your fight or flight response (adrenaline). With accumulation of adenosine around these receptors, you start to feel fatigue or relaxation.
Caffeine binds to adenosine receptors, thereby blocking fatigue normally caused by adenosine accumulation.
Your body uses ATP (adenosine triphosphate) stores for energy during workouts. When used for energy, ATP is converted to adenosine, namely ADP and AMP. ATP’s conversion results in fatigue, but caffeine defers this negative effect.
As for power output, this benefit is more pronounced if you are not caffeine tolerant. So if you take up to several hundred milligrams daily, this isn’t good news. Thankfully, you can change this by replacing some of your caffeine with theacrine, which acts similarly on the adenosine receptors. Or you can become less dependent on caffeine by reducing your dosage amount and frequency when not working out.
How Much Caffeine to Take Before Your Workout
After compiling dosages from popular pre–workout supplements, the median caffeine per serving is 200 mg (data source). This dosage is a good place to start. However, if you’ve never taken caffeine before, try 50 mg to assess tolerance.
Should You take Creatine with Caffeine?
One study lead to the assumption that creatine should not be taken with caffeine. However, this study was never repeated. Also, other studies show that creatine from supplementation doesn’t leave the body for 4 to 6 weeks. This means that creatine could have been in the body for both periods in the study, thus invalidating the results.
Caffeine and creatine actually improve high intensity interval training (HIIT) performance and performance for cardiovascular exercise in general. See Examine.com for a more in depth analysis of interactions between caffeine and creatine.
Caffeine for Wakefulness
If you need to pull an all-nighter or if you need to wake up in the morning, caffeine is usually your best choice. But if caffeine is taken every morning, its effectiveness wears off and you will need to cycle off caffeine.
Should you redose caffeine on an empty stomach or take it with food?
Caffeine is absorbed faster if you haven’t eaten in the past few hours. With an empty stomach, caffeine can reach your small intestine faster where it’s absorbed into your bloodstream.
If you take caffeine in the morning, redose at half your original dosage after about 5.5 hours—caffeine’s half-life. Given that the majority of people wake up between 6 am and 7 am, this explains the “afternoon slump” we feel.
Different Types of Caffeine for Alertness
If you need to be alert in a hurry, caffeine citrate is your fastest option for raising caffeine levels in the bloodstream.
Dicaffeine malate tends to have a longer lasting effect on energy levels.
Beware of caffeine intoxication, especially if staying up all night. Keep track of how many milligrams of caffeine you’ve taken and dosing times. Remember that caffeine’s half-life is about 5.5 hours.
The caffeine for focus goal is more involved and probably one of the reasons you’re here.
Caffeine can either promote or hinder focus. This depends on several factors including:
- Caffeine dosage
- Amount of caffeine already in our body
- Your amount of sleep the night before
- Supplements stacked with caffeine
- Your current stress level
These factors make it difficult to measure the perfect caffeine dose to enhance focus. But you can dial in your dosage by being aware of your current focus level and and calmness.
These levels are used to gauge your current position along what is called the Yerkes-Dodson Law. The diagram shown below is Donald Hebb’s revised version. Hebb updated the curve to show that simple tasks, and not just difficult tasks, can also hinder focus.
To understand this, let’s examine the mental relationship of performance and arousal (or stimulation).
Different tasks require different levels of stimulation for optimal focus. This stimulation level refers to both mental stimulation and supplemental stimulation, such as that from caffeine.
If a task is too easy or too hard…
If a task is too easy, you won’t be as engaged and your focus may suffer. Likewise, if a task is too hard, you will have difficulty focusing.
When learning something new:
You may notice that your mind tends to drift off when learning something new. For example, if you are studying for class or learning a new task for your career.
Your mind has a greater tendency to drift the more abstract or the more difficult a new task is. A perfect example is learning how to solve a math problem beyond your current skill level. It’s only through building familiarity with the new material—with time and practice—that you begin to increase your focus when performing the new task. You can learn more about metacognition, or learning how to learn, in this video series.
Caffeine can help this new material learning and familiarization process. However, caffeine is a double-edged sword, which is why it’s important to…
Manage Stress and Stimulation through Supplementation
When taking caffeine for focus, be aware of your current caffeine or stimulation levels. If you are already nervous or jittery, then more caffeine could further hinder your focus.
Caffeine may actually reduce working memory due to overstimulation.
To reduce stimulation:
If you feel overstimulated or anxious, try taking an adaptogen like ashwaganhda. And if you aren’t already, take L-theanine with your caffeine. Start with a 2:1 L-theanine to caffeine ratio. If the calming effect is too strong, then try a 1:1 mix. The combination of caffeine and theanine is so common that many supplements pair these for focus benefits.
A study was done that showed a dose of 200 mg was optimal for increasing task performance. However, doubling this to 400 mg (do not take this much!) reduced performance.
The subjects in the study had no prior caffeine. Assuming 200 mg cultivates peak performance and caffeine has a half-life of 5 to 6 hours, you should redose 100 mg after this period to retain optimal caffeine levels.
Dialing in Your Dosage
By taking inventory of your current focus level, you can further dial in your adaptogen/L-theanine and caffeine dosage:
If you feel awake but fidgety – take an adaptogen or L-theanine.
If your alertness is lacking and you aren’t feeling nervous – take some caffeine (if you currently have less than the maximum 400 mg in your system).
Counteracting Caffeine’s Side Effects
Insomnia can result from too much caffeine use. If you need to sleep and caffeine’s long half-life is keeping you up, then get caffeine out of your system with NAC or rutaecarpine. Rutaecarpine increases caffeine metabolism, whereas NAC will flush certain substances (like alcohol or caffeine) out of your system.
Indigestion or an upset stomach may be mitigated by taking a different type of caffeine: dicaffeine malate. This caffeine is bonded with malic acid for a 3:1 caffeine to malic acid ratio. The malic acid may promote healthy digestion, especially for those with low stomach acid.
Unfortunately dicaffeine malate is hard to find by itself as a consumer. You will likely have to try it as part of a supplement blend.
The jittery or nervous feeling which sometimes accompanies caffeine usage can be countered in two ways:
Take L-theanine with your caffeine in a 2:1 ratio respectively. If this ratio makes you too relaxed or tired, then try a 1:1 ratio.
The US Army developed an algorithm for optimal caffeine dosage. It’s tailored per individual to predict their optimal caffeine dosage based on data from intermittent PVT (psychomotor vigilance task) tests via a mobile app.
Unfortunately the app isn’t available publicly without licensing. But you can use their data from the study to approximate your optimal caffeine dosage using their open 2B-Alert tool (requires a free registration).
The interface of 2B-Alert isn’t the most intuitive. But it does verify the dosing schedule mentioned earlier of redosing half your initial caffeine dosage after caffeine’s half-life of 5 (or 5.5) hours.
Alertness Over Time and Redosing
This tool demonstrates how caffeine affects alertness after a night of reduced sleep, specifically 3 hours of sleep after a previous night of 8 hours.
If you’re turned off by the interface, here’s a summary of a caffeine regimen during sleep deprivation:
1. Take 200 mg of caffeine after waking up
2. After 5 hours, redose at 100 mg
Here’s the alertness graph with red being the caffeinated schedule (the lower the response time the better) and the blue being the control, or uncaffeinated schedule:
Your alertness, or response time, will be at its worst upon waking until your first dose, and again in the evening. Alertness is at its best within 1 hour of your initial dose, and second best 1 hour after your redose.
Here’s an example dosage schedule after sleep deprivation. Shift the schedule as needed for your wake and sleep hours:
7 am – Wake up
8 am – Take 200 mg of caffeine
9 am – Your alertness should be at its peak
1 pm – Redose with 100 mg of caffeine
2 pm – Alertness should be at its second best
11 pm – Sleep
A More Personalized Dosing Schedule
There’s something the 2-B Alert tool is missing: personalized data. The participants in the study were given alertness tests (the PVT) throughout their day.
You can take the alertness task here. See how your response time corresponds with your dosage and redose times (lower response time = more alert).
Adjust your redose time(s) accordingly. Bear in mind caffeine’s approximate 5.5 hour half-life and ensure there isn’t more than 400 mg of caffeine in your system at once.
More Variables are Needed
The above tools only account for the interplay of two variables over time during a state of sleep deprivation: your alertness and caffeine level.
There doesn’t seem to be a guard in the tool against taking too much caffeine. Instead, alertness on the graph only improves with higher caffeine inputs.
In reality, there is a diminishing return on productivity with caffeine. At some point, stress overpowers alertness and performance suffers. This goes back to the Yerkes-Dodson Law.
An Improved, Multivariate Caffeine Calculator
A study measuring the impact of caffeine and theanine ratios on stress would go far in providing an improved formula. So far, there only seem to be studies on how L-theanine reduces stress and how caffeine increases stress.
A new study should be done to gather data on the stress levels of caffeinated subjects with different L-theanine or adaptogen doses. A stress biomarker such as alpha-amylase can be measured with a simple saliva test.
This data could then be used for a new calculator which gathers user feedback through an intermittent PVT test, along with input for subjective stress levels.
Until this improved calculator is made, you can use the tools and information above to find your optimal caffeine dosage schedule.