This is a question I often get asked by friends and clients, and it often comes from the point of view that many people associate these products with slightly shady or illegal performance enhancers.

However, nothing could be further from the truth, and the products I recommend are all based on natural ingredients. But that doesn’t mean there are no side effects or bad products out there.

Beyond avoiding a poor quality supplement that may not agree with you, there are a few side effects that are both common and likely.

While the supplement industry has done it’s best to reduce these as much as possible, you still have to be aware of them.

From my own experience and through countless conversations with dieticians and nutritionists, I have compiled a list of ways your body might react and how to deal with those situations.

First, though, let’s take a look at what’s in this stuff.

What Is In Pre-Workout Supplements?

Essentially, you will usually find a handful of ingredients in all the top pre-workout products which include creatine, caffeine, citrulline, branched chain amino acids (BCAA), and beta-alanine to name just a few.

While the blend and amount of the different nutritional boosters will vary, the main purpose is to give you a boost of energy to give you more strength and endurance during a workout session.

In most cases, they are powders that you mix into a drink, and you simply take it about 15 minutes before you start training.

There are literally dozens of products available, and it can be quite a challenge to figure out which ones will work best and have the least side effects. We have several recommendations on this site that you should definitely check out.

My Bonus tip is always to check the label, and if you see something hinting at “proprietary blend,” then generally avoid it.

Unless it comes highly recommended from someone you trust, there are enough options with no hidden blends available.

The pre-workout you consume can also be tailored to improve a variety of factors such as endurance, strength, or muscle growth.

- Peter Tzemis, Bachelor of Health Science

What Does Pre Workout Do?

Basically, the whole idea behind taking a pre-workout supplement is to increase energy levels to help you perform better during your exercise and training. (1)

This might sound like some illicit form of doping, but the products you can buy off the shelf are completely legal and contain only natural substances.

You’re not going to suddenly perform like the Incredible Hulk, but a performance boost of 10 to 25% is very achievable. And this will help your body to build more muscle while at the same time helping with weight loss.


Let’s take a look at some common ingredients.

Pre-Workouts With Creatine

Creatine is one of the most sought after ingredients for a very good reason. Every cell in your body needs creatine in order to produce energy. (2)

When your muscles receive a boost of this substance, they will have more energy to help increase strength and stamina for maximum pumps.

One study, in particular, noted that there were very large performance increases (over 15%) in resistance training using weights.

This performance boost will help to build muscles faster while at the same time burning through more fat. Basically, a double boost to your health.

However, some people prefer pre-workouts without creatine as they don't want the side effects that come with it.

Pre-Workouts With Caffeine

Caffeine is one of those stimulants that had been completely underrated for decades. These days, however, you’ll probably struggle to find a supplement that doesn’t contain it.

On average, I have found that the amount of caffeine is usually in the range of 1 to 2 regular 8-ounce cups of coffee. It’s not huge, but you want to keep this in mind if you’re a coffee drinker to avoid the jitters.

The health benefits come in two distinct ways.

First of all, studies have shown that caffeine boosts thermogenesis which basically is a fancy way of saying that your metabolism increases body heat by burning more energy. (3)

Secondly, it has been proven to boost mental and physical endurance by up to 12%. So, you can work harder and burn more fat.

The most prevalent ingredient in pre-workout supplements is caffeine. Typical supplements can contain anywhere from 100 to 300 mg of caffeine, which is up to three times the amount in a cup of coffee.

- Kay Ireland, Certified Group Fitness Instructor

Other Pre-Workout Ingredients And Their Benefits

While caffeine and creatine are the two most common ingredients, there are several others that you can find on the labels of dietary supplements.

A lot of these have very fancy names that most people don’t really understand. So let me try and help you out and show you how these can improve results in your training and fitness goals.

1. Citrulline

This amino acid is produced by your body and is vital for increasing blood flow. However, your body can only produce so much of it naturally.

By getting a boost before you start training, you can heighten blood flow and supply more oxygen and nutrients to your muscles.

One study found a significant correlation between endurance and Citrulline in performance athletes.

2. BCAAs

The fancy science name is branched-chain amino acids, and there will be no rewards for remembering it; just call it BCAA.

Essentially they are types of protein that the body cannot produce, meaning they have to be taken in with food.

While they have only a minor impact on muscle building, one study found that endurance improved in athletes taking BCAA.

3. Sodium Bicarbonate

Yes, that’s basically the same as your household baking soda. While study results have been mixed, there is at least some evidence that it works as a buffer to reduce the buildup of acid.

If it does indeed reduce the amount of lactic acid in muscles, then it could well be an excellent ingredient.

Because it’s both cheap and safe to take, there’s nothing wrong with taking a chance on it.

4. L-theanine

The final ingredient that I like to see in the products I use and recommend is L-theanine, especially when it’s combined with caffeine.

One study has shown that it can significantly enhance your ability to stay focused. (4) This is beneficial both in the gym and at work or during study times.

Now that you’ve learned about some of the substances you might find let’s see what the negative effects can be.

Related Articles:

Possible Pre-Workout Side Effects

First, let me say that most people that I talk to that had negative side effects usually had some allergy or food intolerance to the ingredients. That’s why you should always check the labels to see if there’s anything in it that you know causes you some upsets.

That being said, there are a few things that you can encounter, and you should pay close attention to how your body reacts:

  • Insomnia can happen if you’re a coffee drinker and take your supplement late in the evening
  • Diarrhea is less likely, but the combination of caffeine, sodium bicarbonate, and creatine can have a laxative effect.
  • Headaches and jitters can occur with high caffeine doses.

Before you panic about these, there are some simple steps you can take to avoid them altogether.

Here's a video of Nick explaining the potential dangers of taking pre workout supplements.

6 Ways to Prevent Negative Pre-Workout Side Effects

1. Insomnia

Caffeine impacts people very differently. I often see people in Starbucks at 9 pm, and I wonder how they could possibly be getting any sleep.

Personally, I avoid coffee after 6 pm and on the days where I hit the gym later in the day, I avoid it in the afternoon altogether.

If you know that coffee does affect your sleep, then it’s best to take your pre-workout no later than 7 pm or choose one that is caffeine-free. There are some excellent options available, and I cover a few of them in the reviews section.

2. Diarrhea

Yes, that awful feeling where you just cannot bear to be more than 10 paces from a toilet is one of the more disruptive effects. However, in most cases, this is due to food intolerance, and in the rare circumstances that it happens, there is a simple solution.

First of all, pre workout on an empty stomach is not a great idea, especially after fasting. Get at least a little bit of food into you first.

Secondly, reduce the dose to half the amount to start off with. It might just take your stomach a few days to get used to it.

3. Dehydration

You might find that you feel a lot thirstier than normal when you’re exercising and this can be due to the combination of substances in your chosen supplement.

Some are specifically designed to help you tap into glycogen reserves which is an energy resource that binds directly to water.

My main tip here is not to wait until you feel thirsty and your mouth is dry. This is actually a more advanced stage of dehydration and will have a significant impact on your performance.

So, make sure you drink plenty of water throughout the day and take constant sips while you’re training.

4. Headaches

These are mostly associated with high caffeine doses and dehydration. Some ingredients are added to boost your blood flow, and they do this by expanding blood vessels. Some people are sensitive to this effect in the brain.

It is less common for these products to trigger migraines, but if you do find that you’re consistently suffering from headaches, then you should stop taking the supplement for a few days.

You can then start with a smaller amount, and it’s always best to take a few extra cups of water.

5. High Blood Pressure

One of the effects of all stimulants is an increase in your heart rate, and this can also cause high BP. If you have issues with your BP anyway, then it’s probably best to avoid these stimulating substances altogether.

It’s important to check your BP before and after working out. If it’s significantly elevated at these times, then start by choosing a caffeine-free product.

Just take your supplement in moderation and you'll do just fine.

6. Tingling Sensations

Some people are more sensitive to certain ingredients like beta-alanine or vitamin B3, and as these directly impact the nervous system, there is a chance that you’ll feel some tingling throughout your body.

It’s perfectly normal and usually only lasts a short while. When this does happen to me, I find it more distracting than problematic, but I’ve become used to it and just ignore it.

Once you start training it usually goes away pretty quickly.

So, you have a few tips to avoid negative effects, and the last question to address is: when to take pre workout for minimum negative effects?

I generally recommend not taking it first thing in the morning, and no later than 7pm. If you stick with that, then you’ll avoid pretty much all unpleasant feelings.



1. Can You Take Too Much Pre Workout?

Yes, you can take too much pre workout which can leave you feeling unwell and jittery. The main reason for this is that too many stimulants like caffeine will increase your heart rate, cause stomach discomfort and a lack of mental focus.

2. Can You Take Pre-Workout On An Empty Stomach?

Yes, you can take pre-workout on an empty stomach, but some people might encounter stomach upset and even diarrhea. The advantage is that it’s absorbed very quickly, but I generally recommend at least a small snack before you take it.

3. Can Pre-Workout Cause Kidney Failure?

Pre-workout can only cause kidney failure if taken in excessive amounts while ignoring negative side effects. Some ingredients cause high blood pressure and dehydration which can negatively impact your kidneys. But actual failure is highly unlikely and would require sustained high doses.

4. Is Pre Workout Bad For Your Heart?

Yes, pre-workout can be bad for your heart if you take it in very large doses or you have an underlying heart condition. Both caffeine and creatine increase the heart rate and blood pressure, but as long as you stick to the recommended amounts and don’t have known issues, then you should be just fine.

5. Does Pre-Workout Make You Fat?

No, pre-workout doesn’t make you fat, but it can increase your body weight. The reason for this is that muscle weighs more than fat, and as your body burns through more fat and produces more muscle, you might actually notice a weight increase. It’s more important to look at your BMI in these situations, than just what the scales are saying.

6. Is Pre-Workout Addictive?

No, pre-workout isn’t addictive, even though some people say that caffeine has some addictive properties. You might feel like you become dependent on it for maximum performance, but there are no studies confirming that any of the ingredients are addictive.

7. Can Pre-Workout Cause Or Worsen Depression?

Generally speaking, pre-workout does not cause or worsen depression. But there are some products out there that contain ingredients that have been tied to depression. Look out for artificial sweeteners like Aspartame or a substance called Dimethylamylamine (DMAA) and avoid them if you have mental health concerns.

Related Post: Does Pre-Workout Go Bad?

Do Pre-Workouts Work?

Yes, pre-workout supplements do work, and there are many studies to back up the reason for including certain ingredients.

Top performance and professional athletes take these products on a consistent basis because of the benefits they provide.

At the same time, you have to be aware of the negative effects so that you can look out for them and take immediate action.

If you’re still wondering: Should I take pre workout supplements?

The answer is yes, as long as you monitor the side effects and take actions to reduce them.

Hopefully, the above tips will help you so that you can avoid most issues and if you have some more tips to add, then please leave a comment on our Facebook page.

You can also read: Can you snort pre-workout here.


  1. Tia Ghose, Senior Writer, The Truth about Pre-Workout Supplements, retrieved from
  2. Rudy Mawer, MSc, CISSN, How Creatine Helps You Gain Muscle and Strength, retrieved from
  3. Astrup A, Toubro S, Cannon S, Hein P, Breum L, Madsen J., Caffeine: a double-blind, placebo-controlled study of its thermogenic, metabolic, and cardiovascular effects in healthy volunteers., retrieved from
  4. Michael J Breus Ph.D., What You Need to Know About L-theanine, retrieved from


About the author

  • Wow!!! This is so great! Such an amazing resource for beginners like me. I like this particular product I tried a sample of, but the tub is so expensive I don’t think i can maintain it! So I looked for ways on how to do it yourself and this is probably the best one I have found! So detailed and so much useful stuff! I will definitely try making one for myself this weekend — so excited to try it out! If this goes well, then I don’t need to buy that expensive product ha ha so wish me well!

    By the way, I’ve been reading your blog the whole day today. I love it. Definitely makes me think about my lifestyle choices! Not in a judgmental way though, but more on an educational way, he he! Will bookmark your page and read more of it, im sure there’s a lot more value in here that I haven’t touched

    • Hi Fern, I hope you read my comment (the one after this lol) i know you want to save some money but trust me, the effort isn’t worth it haha there are cheaper products out there that you can buy and will last for a month or two, those should be good!

      • Hi Yosef, thank you! I actually realized that as I was researching for the ingredients. Haha those ingredients are difficult! They are difficult to spelll and difficult to find lol thank you for your insight. There’s this product that I enjoyed but I guess I will have to substitute something cheaper. It ‘s sooooo expensive, like a hundred bucks for a month’s supply like ?????? that’s just too much for me. i am a student and do not have much in the bank, i work part time so I save what I can. yeah, need to research more for a cheaper product

  • I also don’t recommend making your own, just buy the stuff on the grocery or online and you’re good. It takes too much time. Also, I don’t have all the ingredients on my local grocery so I would have to research still on where and how to get those especially the ones that sound so foreign to me. If you have the time and resources, sure go ahead and do it, but I think it will still end up being costly considering that you can’t buy those things on a per serving basis! You have to buy them in pouches that maybe has 1kg of it, and you won’t be needing that much. So personally, it’s not worth my time and money. I’ll just shell out $40 and there, I have my product. It’s that easy!

    • 100% agree with you, brother. I tried doing this on my own and straight up failed, it was chunky and tasted like an expired chalk, imagine that, it’s not that an unexpired chalk tastes good. And regarding the ingredients, they are not readily available anywhere, so I looked online and found some but most of them were expiring in a few months’ time 🙁 I was only able to make a few servings that lasted me almost a month, after that, my ingredients have all gone bad. That’s one of the downsides of buying online, most of them are almost expired, more so if they’re being sold at a low price! such a sad experience. i ended up spending over 60$ instead of just getting a tub for half the price. that’s a lesson learned, and i hope everyone reading this listens to me lol i don’t want to you to go through the hassle i went through

  • Hi, i have a question, where do i get these ingredients? Do i get them from the drugstore? or my local grocery? not sure about them, tried searching online and can’t seem to find any info on where to buy cutruline malate or whatever that is.

    • Hi Madison, most drugstores have those, GNC or anywhere that sells the same products. However, as most people here have commented, making your own isn’t going to a walk in the park. It’s time consuming and i find that a tiny mistake in measurement can mess up the entire thing (not that I experienced it, oh yes i actually did and mine tasted like crap). So you are going to have to be careful with that if you want something good. You also have to use the same exact tools and measurements all the time. There’s no estimating in here everything has to be to a T. I don’t know, i don’t have the patience for that, but may be you have.

      • Thannk you for your insight, Oakley! I appreciate it. I actually just called my local GNC and sadly they don’t have these things so I might have to look somewhere else. I have a favorite one that i take all the time but i thought this would be a good way to switch things up, like an experiment! Ha ha, i will definitely take your advice into consideration. As soon as I have everything I need, i’ll make one and will let you know of the outcome! If it turns out great, then good, but if not, then i’ll just remember it as a funny experience lol. Thanks!

        • Sounds exciting, do let us know what happens! Excited to hear about it. If anything, I’ve tried it once before and it went well, the second try did not. THat’s why I mentioned consistency in measurement and everything else. I agree with you though, it’s a fun experience, albeit messy and tasted awful lol. I have a feeling you’ll go back to your favorite brand but whatever happens, we won’t judge, hehe all the best to you!