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Pre Workout At Night (Who Can Take It, Side Effects + More!)

I’ve never seen a supplement that splits so many opinions as much as pre workout.

Some people swear by it and couldn’t live without it.

Whereas others would rather flush their money down the toilet.

Like many supplements, the time of day that you take pre workout has a huge impact on whether it benefits you or works against you.

Can You Take Pre Workout At Night?

You shouldn’t take pre workout at night as the high amount of caffeine in pre workout severely disrupts your sleep. This makes recovery from your workout much harder. Also, pre workout contains nootropics which negatively affect your sleep.

In this article, we discuss why you should avoid taking pre workout at night, who should take pre workout at night, the latest time to take pre workout and much more.

Why Most People Shouldn’t Take Pre Workout At Night

Most pre workouts contain a high amount of caffeine in the range of 150mg to 300mg per serving.

Why is this bad?

Well, there are numerous studies which show that caffeine can severely disrupt sleep.

In one study, subjects took either 400mg of caffeine or a placebo at different times of the day.

Some took it when going to bed, others took it 3 hours before going to bed, and the rest took it 6 hours going to bed.

The results showed that all the subjects who took caffeine had significant sleep disturbance.

(Yep – even the ones who took it 6 hours before going to bed.)

So, by taking pre workout at night, you can wave goodbye to a good night’s sleep.

Unfortunately, many people underestimate the importance of sleep.

Not only will disrupted sleep make muscle building a lot more difficult, but it can also increase your risk of many chronic diseases, including:

Who Can Take Pre Workout At Night?

Image Credit: Wikipedia

Like most things in life, there are exceptions to the rule.

In my opinion, only one small group of the population would potentially benefit from taking pre workout at night.

That group being night shift workers.


Well, for obvious reasons, night shift workers have a different sleeping pattern to the rest of us.

So, when they take pre workout at night, the caffeine will have left their system by the time they finish work and go to sleep.

Another reason why I think it’s fine for night shift workers to take pre workout at night is that it may help improve their performance at work.

For example, in a study of 9003 British adults, those who consumed the most caffeine had improved reaction time, verbal memory, and spatial awareness.

Also, some pre workouts contain nootropics such as L-Theanine, which has been shown to improve attention when taken alongside caffeine. (Source)

What’s The Latest Time To Take Pre Workout?

If I can’t take pre workout in the evening, then when’s the latest time I can take it? I hear you ask.

Well, if you value your sleep (which you should!), then I’d take it based off your bedtime.

For example, if you go to sleep at 10pm, then the latest I would take it is 8 hours before your sleep, so 2pm.

If your bedtime is 11:30pm, then the latest I would take it is 3:30pm.

Why would I take it at least 8 hours before going to sleep?

Well, research shows that the half-life of caffeine is around 4 hours.

In other words, it takes around 4 hours for your body to metabolize half of the caffeine consumed.

So after 8 hours, your body should have processed most of the caffeine.

To be super clear, this means if you take pre workout at 2pm, then your body will have used up the caffeine by 10pm.

Can You Take Pre Workout Before Night Workouts?

In my eyes, this is a firm no.

There’s a strong trade-off here between energy for your workout and sleep quality.

By taking pre workout for your night workout, you’ll feel more energized however your sleep quality will reduce based on the reasons outlined in this article.

Sleep quality is so, so important when it comes to recovery, muscle growth, and all that good stuff.

So it’s just not worthwhile risking all of that for a boost of energy for your workout.

Can You Take Caffeine Free Pre Workout At Night?

Caffeine free pre workout supplements are becoming more and more popular these days.

Even the big brands, such as MyProtein and MuscleTech offer them in their product line.

But does the lack of caffeine make it ok to take it in the evening?

Well, it depends…

The first thing you need to consider is what other ingredients are in the pre workout.

Is it just creatine, BCAAs and a few vitamins?

Or are there added nootropics and other stimulants too?

If it’s the latter, then I’d personally avoid taking it in the evening.

While it may not be as damaging to sleep as your standard pre workout, the nootropics and stimulants could result in sub optimal sleep.

What Supplements Should You Take At Night?

If I shouldn’t take pre workout in the evening, then what supplements should I take?

Good question.

Here are my top 5 supplements to take at night.


Melatonin is a powerful hormone that’s produced by the pineal gland at night.

It helps manage your sleep cycle by regulating your internal body clock.

Interestingly, a review of 19 studies found that Melatonin increases the amount of sleep, boosts sleep quality, and reduces the time taken to fall asleep.

Hence, it’s no surprise that many people refer to Melatonin as the sleep hormone.


Magnesium is a mineral that many people are deficient in nowadays.

(Some estimates suggest that 80% of American adults have lower than ideal levels!)

Unfortunately, low levels of Magnesium have been linked to many chronic diseases including:

So for this reason, supplementing with Magnesium is super important.

In one study, 46 elderly subjects took either 500mg of Magnesium or a placebo each day for 8 weeks.

By the end of the 8 weeks, those in the Magnesium group had significant increases in sleep time and sleep efficiency.


Phosphatidylserine is a natural compound produced in the body that covers and protects every single cell we have.

It’s also found in many foods, including soy, beef liver, chicken liver, and egg yolks.

While it’s often used to improve brain function, many people take it to improve their sleep.

How does it improve sleep?

Well, it helps lower cortisol – the stress hormone – which results in you feeling calm and relaxed.

In fact, ever since I started taking Phosphatidylserine before going to bed, I could fall asleep within minutes.


GABA is an amino acid that’s produced naturally in the brain.

Its main job is to lower neuronal activity in the brain and nervous system, which results in various effects on the body and mind, such as:

  • Lower stress
  • Improved mood
  • Improved sleep quality
  • Increased feelings of relaxation

In one study, 100mg of GABA reduced the time taken to fall asleep by 5.3 minutes.

Valerian Root

Valerian Root is a herb that’s known for its calming effects.

It’s been used for over 2,000 years to help treat a variety of conditions, including insomnia.

One study compared the effects of Valerian Root and a placebo on sleep quality.

Interestingly, 44% of those who took Valerian Root reported perfect sleep and 89% reported improved sleep.

In another study, 16 people with insomnia took either Valerian Root or a placebo.

According to the results, those who took Valerian Root achieved deep sleep 8 minutes quicker than the placebo group.


Wrapping things up, it’s clear that taking pre workout in the evening is a bad idea for 99% of you who are reading this article.

Simply because its high caffeine content can wreak havoc with your sleep.

But the small percentage of you who work night shifts may benefit from taking it at night, due to its effects on focus and mental performance.

I also wouldn’t advise taking caffeine free pre workouts at night due to the potential effects of nootropics which are added to substitute caffeine.

To be clear, that’s just my opinion though. Some people may not have a problem with falling asleep after taking nootropics.

I know that I do, but we’re all biologically different, I guess.

Well, thanks for sticking with me to the end of this article.

I hope it’s been an enjoyable read and hope you’ve find it useful.

Take care, and I’ll see you in the next one.


Related Questions

Should You Drink Coffee At Night?

Some people (including myself) drink Coffee instead of pre workout, as it’s cheaper, healthier, and tastier.

(In my unbiased opinion 😉)

So, is it wise to drink Coffee at night?

Well, a cup of Coffee has around 100mg of Caffeine.

While this is less than your standard pre workout serving, it’s enough to disrupt your sleep.

And so, I wouldn’t recommend drinking Coffee at night.

(Related Reading: What’s The Best Time To Drink Black Coffee For Weight Loss?)

Is It Ok To Work Out At Night?

Not only is it ok to work out at night, but some studies suggest it’s better to work out at night.

For example, a study of 42 men compared the effectiveness of training in the morning and evening.

In simple terms, it compared their muscle growth, endurance, and strength.

By the end of the study, those who trained in the evening gained more muscle than those who trained in the morning.

(Related Reading: What’s The Best Time Of Day To Workout For Muscle Gain?)

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