15 serious pre-workout side effects you can’t ignore

Pre-workout side effects

I am sure you would agree with me …

That most of people look up to pre-workout supplements as their best bet to boost their energy levels and performance during their workouts but few know how to safely use them. As a result, they are bound to have a taste of these harmful pre-workout side effects.

Then are you the one who does not want to be like those?

Then, read on to find what are some of the common serious side effects of pre-workout supplements and what can you do to avoid them.

Ingredients of a pre-workout: What is in a pre-workout supplement?

Ingredients of a pre-workout: what is in a pre-workout?

Before you get you know about the common ingredients of a pre-workout, let’s first find the meaning of a pre-workout.

So, what does a pre-workout actually do to you?

A pre-workout supplement is essentially anything taken before a workout to boost your performance and energy levels.

In layman terms, it is basically a kind of added fuel that gets the best out of you at the gym i.e it delays fatigue and keeps you pumped up throughout the duration of your workouts.

Pre-workouts are taken in a number of forms from shakes to pills with each form varying in its cost and ingredients. Commonly, they are mixed with a drink to make their intake quicker and tastier. 

However, a pre-workout is never limited to simple carbohydrates only. Rather most of the pre-workout supplements contain more than just carbohydrates; it’s a good mix of vitamins, proteins, and good metabolizers.  

Following is a list of the most common ingredients of a pre-workout.

1. Caffeine – This stimulant has been shown to increase muscle strength and output during exercise while reducing fatigue.

2.  (BCAAs) Branched-Chain Amino Acids They are primarily involved in breaking down and synthesizing new proteins in muscles.

3. Beta-Alanine Beta-alanine helps you sustain workouts for a long time.

4. Creatine Monohydrate  –  A type of creatine has been shown to increase high-intensity exercise capacity and lean body mass gains from exercise

5. Vasodilators –  Vasodilators help to maintain an increased supply of blood to working muscles to help delay fatigue.

Definitely you would be wondering now whether pre-workouts are actually good for you or not. While there is no doubt that pre-workouts can be an X factor in your gym but these great benefits come at a price.

Read below and tell me if can you relate any of these pre-workout side effects to you.

Common pre-workout side effects

Common pre workout side effects

 The following are some of the most common side effects associated with pre-workout supplements.

1. Dehydration

Dehydration pre workout side effect

Dehydration is one of the most common side effects of a pre-workout.

Actually, when you take a pre-workout supplement, your body tends to lose a lot of water to sweating during workouts. To compensate for that lost water, water from other areas of your body runs towards your working muscles of body parts causing instant dehydration.

That’s why you are advised to time and again to keep your body hydrated throughout your day whether you are thirsty or not because it will help you to maintain adequate hydration levels of your body.

How to Prevent this?

Consume a sufficient amount of water before, in the middle, and at the end of your gym session to avoid this pre-workouts side effect.

2. Headache

Headache pre workout side effect

Headaches are another common issue with pre-workouts which basically happens due to two basic reasons:

1. Dehydration- So, one of the most common problems like hydration can lead to another serious problem i.e headaches. 

Essentially, since water forms a protective layer around your brain; when dehydration occurs, this brain protection is vanished causing your brain to directly bump with the skull give you an instant sensation of pain in the form of headache.

2. Vasodilators – Also known as ” the muscle pumps”,  found in the form of citrulline malate, arginine, and beta-alanine, act as vasodilators i.e cause expansion of blood vessels in your head giving you a sense of headache.

How to prevent this?

There are two things that you can do in this situation.

  1. Either you can completely remove such supplements that have these ingredients OR
  2. You can first test its effects by intaking a lesser quantity per serving while taking a lot of water before and after your workouts.

3. High blood pressure

High blood pressure pre workout side effect

High blood pressure is another major concern related to pre-workouts primarily due to stimulants found in them without which most of the pre-workouts are incomplete

However, this issue can really aggravate if you have a history of blood pressure problems. That’s why health experts stress upon consulting your doctor before starting a workout routine involving a pre-workout supplement.

 Furthermore, if you are incorporating a lot of HIITs ( Higher intensity interval training), then you are risking this problem to escalate to very dangerous levels. 

How to prevent this? 

Always consult your doctor for taking these stimulants as pre-workouts and try keeping your HIITs to minimal intense levels.

Another note of caution is to always test pre-workouts before you intake. This can be easily done by sample testing as most of the companies dealing in the pre-workout supplement offer this facility of pre-testing.

4. Lost of sleep – Insomnia

Lost of sleep insomnia pre workout side effect

So, you have been very busy all throughout the day and feel exhausted for the gym session and you think why not take a pre-workout supplement to boost your performance & motivation to get that shit done.

But this can land you in very serious trouble that will aggravate your tiredness i.e it will deprive you of your crucial hours of sleep which is a panacea for all sorts of tiredness.

In most of these insomnia and sleeplessness issues, Caffeine is a common culprit.

Now,  since most of the pre-workouts are filled with caffeine in handsome amount per serving i.e at least about 200-400 mg of caffeine, this much does is bound to give you sleepless night hours.

How to prevent this?

It is that simple: if you crave a good night’s sleep then please completely avoid pre-workouts at night for the sake of comfortable and refreshing sleep.

Another thing that you can do to avoid/minimize the caffeine side effect is by lowering the dose/per serving size which can be metabolized faster in your body and does not cause a problem for you in the late-night hours.

5. Diarrhea

Diarrhea pre workout side effect

Unfortunately, diarrhea is another side effect of common pre-workout supplements. 

Primarily, it is because of laxative ingredients like  magnesium, taurine, Yohimbe, creatine, arginine, sodium bicarbonate, and caffeine

How to prevent it?

A simple and quick fix is to drink a lot of water before, during and after your workouts which will help dilute the ingredients and save your from rounds of the toilet without hurting the effectiveness of your workouts

However, if your diarrhea issue persists, please never hesitate to visit a doctor because it can underline a more serious issue that needs medical treatment.

6. A burst of odd prickly & tingly sensations

tingling sensation pre workout side effect

Soon after your intake of pre-workout supplements, an across-the-body running sensation which tickles and prickle your feet and hands but since each individual is different, some feel much worse. 

This becomes so uncomfortable sometimes that it feels to you that if your skin is getting flushed or blotched. 

Why it happens is very easy to understand: Since the very basic purpose of a pre-workout supplement is to make you realize that since something is happening with your body, hence, this pre-workout is working too.


Common ingredients causing this kind of sensation are either 1) Beta-alanine & 2) Niacin or Vitamin B3

How to prevent this?

The tingly and prickly sensations you get from some pre-workout supplements are generally harmless and you don’t need to be concerned about;As time passes, what you are feeling will subside and you’ll go back to feeling normal.

Also, If you don’t enjoy this side effect, it would be recommended that you simply stay away from pre-workout supplements that contain these ingredients. 

7. The long phase of Stress and Anxiety

stress and anxiety pre workout side effect

Some of the biggest pre-workout side effects include – increased stress, anxiety, among others like blood pressure, dehydration, etc. Stress plays an important role in Training and recovery.

Stress is a crucial part of the fitness journey because it is the stress on our bodies that make it more adaptive to it and overall our strengths increase.

However, the problem is when stress becomes too unbearable or hard to recover and our progress in the gym stalls.

8.  Acute supplement addiction/dependence

acute supplements addiction pre workout supplement

As you continue to tolerate ingredients of supplements, you can become a supplement addict and you can’t imagine thereafter living without it. 

This is where the pre-workout supplements are dangerous. Caffeine is a common addictive element in most pre-workout supplements

Ask yourself: what is the difference between a dose of marijuana or a dose of caffeine if they express in the same way. So much so, even a slight movement of workouts seem tough to do without taking in a portion of your supplement.

What is worse about it that If you dare to stop yourself from pre-workout supplement consumption, you are very much likely to suffer these conditions

  • sleeplessness
  • Headaches
  • lethargy
  • Depression
  • muscle pain
  • muscles cramps
  • Bad mood and behavior

9. Pre Workout tolerance (ineffectiveness)

pre workouts can make you ineffective

Pre Workouts are notorious for getting ineffective over time. You will soon find out yourself.

As you keep getting regular does of your pre-workouts, your benefit levels achieved from this pre-workout slowly and surely fall down until you become completely tolerant of these pre-workouts.

Our body is very good at getting used to new situations and for you to have the desired results you have not other choices but to gradually increase your serving size.

10. Pre-Workouts can have dangerous and harmful chemicals

pre workouts can have dangerous chemicals in them

In some serious cases, some pre-workouts can contain ingredients that are dangerous or even fatal to consume. This usually happens when regulators are unable to keep a check on the dangerous pre-workout supplements.

For instance, in a random test of OTC supplements, NSF (National Science Foundation) found these dangerous and banned chemicals in them.

  • DMAA: officially known for a number of deaths in soldiers and athletes.
  • DMHA: a stimulant directly affecting your nervous system commonly known as octodrine. 

It is responsible for absorption of dopamine in large quantities but supplements generally label it as a “fat burner”

  • Dimethylamylamine: it is officially banned by anti-doping agencies, not found as natural chemicals and only manufactured in labs.

11. Unknown/potentially harmful ingredients

Unknown and potentially harmful ingredients of pre workouts can be dangerous

Along with the dangerous chemicals, these pre-workout supplements can also contain a variety of unknown ingredients. This is usually due to the manufacturer trying to hide potentially ingredients in the pre-workout.

They do this because selling products that contain banned ingredients is illegal, and several countries around the world have put bans on different ingredients. 

So,  when they hide the banned product under an unknown ingredient name of a natural extract, they usually won’t get caught unless people have a reason to take a closer look.

For example, 

Many pre-workouts list 2-aminoisoheptane as an active ingredient. They claim that this ingredient is a natural compound that comes directly from a plant in the nightshade family like monkshood.

You may find it as Aconitum kusnezoffii on the label.

12.  Inflammation-causing emulsifiers

pre workouts can have inflammation causing emulsifiers

Emulsifiers are basically synthetic agents work as supplement stabilizer. On the face of it, there does not seem to be a problem with it but recent studies indicate that it actually can damage your intestine and cause serious body inflammation.

To be exact, recent studies on animals found out that emulsifiers in your diet can completely alter the bacterial content of your digestive tract.

This coupled with inflammation and intestinal damage can lead to serious health problems like Leaky Gut syndrome and other issues like:

  • Abdominal pain
  • Diarrhea
  • Nausea
  • Reproductive and fertility failure

13. Pre-Workouts can start acting as Diuretic

Pre workouts can sometimes act as diuretic

Diuretics medication basically helps the removal of excess water through kidneys. This is suited for problems of high blood pressure or extra water retention. 

However, you need to exercise caution when working out excessively because than you need extra water and you can’t afford to lose too much water during exercises. 

So, ignoring the diuretic effects of pre-workout supplements while working out heavily, you are inviting dehydration because then your body’s hydration needs will pull water from the whole of the body to support your working muscles.

14. Pre-Workouts can contain harmful artificial sweeteners and colors.

pre workouts can have some time dangerous artificial sweeteners

An artificial sweetener is something put in pre-workouts to replace actual sugar. They’re generally sweeter than sugar as well, and this means that the manufacturers don’t have to use as much of it in their products. 

However, recent studies and researches have uncovered serious health issues that come with the consumption of these artificial sweeteners and colors.

According to one study, an artificial sweetener like High Fructose Corn Syrup(HFCS) was found to be the leading cause of diabetes. 

That’s why the Food and Drug Administration (FDA) has been regulating the use of artificial sweeteners in the US and it has declared these as ‘food additives’ instead of GRAS and listed them to be unsafe for consumption.

Since it is generally cheaper to find alternative rather than natural coloring agents, therefore almost all pre-workouts will have artificial colors mixed with them.

Recent research also found these artificial colors and dies to cause ‘learning disabilities’ in children and this was found to be truer in the case of children who are hyperactive.

15. Kidney-Failure

pre workouts can cause kidney failure

Kidney failure is certainly an extreme case of dangerous pre-workouts side effects but it can’t be denied or downplayed. The major reason it happens is because of the higher-than-recommended intake of certain pre-workout ingredients. 

For instance, many of the sports nutrition consists of a very well known protein ‘creatine’. 

This creatine, when taken more-than-recommended dosage, can signal your body to completely shut down its creatine production which leads to a massive increase in production of renal-byproducts such as ‘creatinine’-  causing potentially permanent kidney failure.

Takeaway: What to do about Pre-workout side effects?

What to do about pre workout side effects?

There are some serious health & fitness side effects associated with almost all of the pre-workout supplements that you can ignore only on your own peril.

While your efficiency for the workouts is important but so is your health.

Think about it. How badly your fitness routine would suffer once you are not able to get off your bed simply because you are suffering from health issues caused by one of your supplements.

So, taking some precautionary measures like knowing well what exactly and how much are you intaking, is very important.

Or else, if you want to completely eliminate these manufactured supplements, then you might want to have a look at some of the homemade pre-workouts.

C4 pre-workout side effects

C4 pre workout side effects

What is the C4 pre-workout?

 C4 is a pre­workout supplement powder that is prepared by mixing the powder that comes in a miniature package, with water and consuming it; its main benefits include enhancing their performance during workouts.

A number of heavy weightlifters indicate that they felt more enthusiastic in the gym after they consumed the product. 

Common Ingredients of C4

  •  beta-alanine,
  •  creatine nitrate, 
  • arginine, 
  • caffeine, and an energy blend all of which are supposed to give the user a physical, mental, and strength boost.


Manufacturer:  The company Cellucor

who promises that their product will provide an extra pump in energy and motivation while enhancing their focus on their heavy workouts.  

Common side effects of C4 pre-workout supplements

  1. C4 is banned in many sports because of an ingredient that C4 contains, synephrine, which may give athletes an edge over their opponent. 
  2. The most alarming thing about C4 pre-workout may be a warning label on the package, which informs the user not to use the product for more than 8 weeks and not to consume any caffeine throughout the day if the supplement is taken, this includes products such as coffee and tea.
  3. Furthermore, the label reveals that the product is not intended for people under the age of 18, and the label gives a lengthy list of medical conditions for which the person considering using the product should talk to a physician before use

Research evidence: what do research studies say?

Research evidence of c4 pre workout

Hypothesis: The concentration of C4 in zebrafish wells resulted in a high mortality rate among them. 

Experiment setup:

The purpose of the experiment was to observe and record the side effects on zebrafish embryos when they were exposed to solutions of C4, a pre­workout supplement.

 In the two trials that were conducted, five different concentrations of C4 were tested, and in each trial, control was set up, which contained only Embryo Media and no C4. 

The higher concentrations, tested in the first trial, included 22 mg/ml, 44 mg/ml, and 66 mg/ml of C4. The second trial tested lower concentrations:0.32 mg/ml and 2.64 mg/ml of C4.

The Results?

  1. many of the zebrafish embryos died due to an exponential increase in their heart rate. These effects observed could pose a risk of developing human embryos.
  2. This experiment indicated how workout supplements can affect humans. Also, it was concluded that C4 supplement can be dangerous even in small quantities as indicated by death of zebrafish embryos even with very little concentration of C4 

What are some benefits of a pre-workout?

Benefits of a pre workout

Following are some of the common ingredients of pre-workout and their benefits

1. Caffeine

Caffeine pre workout  benefits

Caffeine is the most common and first choice for most of the pre-workout supplements in the fitness industry. The reason is because of its ability to energize your workouts and help in fat burning.


It is a well-known energy booster that is perfect for both short and long bouts of intensive workouts.Due to its fatigue delaying abilities, it can keep you smooth and working through the most intensive of all workouts.

If you are night sleeper, don’t take it’s heavy does at night because it can mess with your sleep.

Best dose per serving:  300-350mg

2.  (BCAAs) Branched-Chain Amino Acids

pre workout BCAAs benefits


Branched-chain amino acids like leucine, isoleucine, valine, arginine, etc play a central role in protein metabolism, i.e the process of breaking down and production of muscle proteins.

These are also known for soothing your muscle soreness when you undergo your most intensive workouts.

Best dose per serving: about 7 g in pre-workouts, 22 g approx whole day.

3. Beta-Alanine

benefits of beta alanine pre workout


Beta-alanine helps you maintain your pump and intensity to do some extra reps and sets of your workouts.

Also, it is harmless and normal when you initially you take, but it can give you a momentarily few tingly sensations if you exceed the dose limit.

Finally, It serves as H+ ions buffer which helps your muscles to keep them working without pain and fatigue.

Best dose per serving: about 2-6 g

4. Creatine Monohydrate

creatine mono hydrate pre workout benefits


Serves a primary source of strength for your heavy workouts and keep you going with a constant flow of energy till the end. It also plays a major role in building and repairing your muscles.

However, studies have suggested that taking creatine as a whole is more important than pre vs post-workout debate.

Best dose per serving: 7 g in a pre-workout but 22-25 g overall in a day.

5. Vasodilators

Nitric oxide pre workout benefits


L-arginine, L-citrulline are examples of vasodilators that maintain an increased flow of blood by increasing the quantity of nitric oxide in the blood.

This extra flow of blood keeps you pumped up for your workouts as it helps to delay fatigue during workouts.


When to take your pre-workout?

Answer: 25-30 minutes before workouts
The best time to take pre-workout as recommended by experts is to take them almost half an hour before you are going to workouts. Why?
Because a time of 30 minutes before your workout allows your pre-workouts ingredients to metabolize properly and are ready to give you that extra pump, energy during your workouts and delay fatigue i.e it would help you out in getting those extra reps and sets to boost your fitness goals

Q: How long does pre-workout last?

About 4-6 hours.
Answer: Well, the exact answer to this question depends upon factors like your sensitivity to certain pre-workout ingredients discussed above, particular Caffeine.
However, an average person can feel the effects of pre-workouts for about 4-6 hours after he has consumed it.

Q: How to get rid of pre-workout side effects?

Answer: You can’t completely get rid of all pre-workout side effects but you can minimize their risk by regulating their dosage level or you can consult your doctor to get advice about how to keep your body safe from dangerous workout side effects.
Furthermore, Always buy authentic, certificated and original products from reputable manufacturers and never forget to read all the ingredients and find if it contains harmless ingredients for your body.

Q: What are the side effects of not using a pre-workout after taking it?

Answer: Supplement addiction & supplement tolerance.
As mentioned in my post above, over time, your body can become supplement tolerant and it can become addictive which causes restlessness until you consume your pre-workout.

Q: What are the negative side effects of c4 pre-workout?

Answer: In extreme cases, c4 pre-workout can prove to be deadly.
Answer: In a scientific research experiment, the C4 supplement was found to be deadly for zebrafish embryos which can lead to the conclusion that it may not be fit for human consumption. And if consumed, it can prove deadly

Q: What are the side effects of caffeine pre-workout?

Answer: Addiction & insomnia/sleeplessness
Caffeine is a stimulant which can be addictive and mess up with your sleep hence it can cause insomnia

Q: How long do pre-workout side effects last?

Answer: In general, the effects of a pre-workout kick in about 30 minutes after consumption. From then on, the effects are going to last from 1.5 hours to 2.5 hours, and even up to 6 for some residual effects.

Q: Is pre-workout really worth it?

It totally depends on you. 
Answer: If you continue to use in moderation & user manual and according to the advice & recommendation by your fitness trainer/expert, you should not have any serious problem.

Leave a Reply