Does pre workout have side effects

There isn’t a simple answer to this question. Depending on the person and the type of ingredients, even the best pre-workout supplement can have varying side effects. If you are someone who is sensitive to large amounts of stimulants then it might be better to avoid pre workout supplements altogether. However, you can try some alternatives like taking creatine, beta-alanine, and amino acids supplements separately. If doing something like this does not interest you, a pre-workout supplement can still be a good option. Here is a quick overview of the most common side effects.

Dehydration: Dehydration can come from the supplementation of creatine, caffeine or other high-stimulatory ingredients. Drinking sufficient water can prevent this.

Diarrhea: Diarrhea can come from the influx of all the different ingredients, which is more-so dependent on how your body reacts to them. Supplementing too much pre-workout at a time can also cause this, following correct dosage can help you avoid this.

Anxiety: The feeling of anxiety is often magnified by some of the ingredients found in pre-workouts. Avoiding products with tremendous amounts of stimulants is a good way to evade this side effect.

Vasoconstriction: This side effect occurs from ingredients like caffeine. If you have high blood pressure, you should avoid pre workouts altogether.

Sleeplessness: Can transpire from high doses of caffeine, having at least a couple hours to come down from the effects before bed is essential if you want to avoid insomnia.

Dizziness: High amounts of stimulants may lead to the feeling of dizziness.

Upset stomach: Depending on how your body reacts to these different ingredients, users may experience the onset of upset stomach. Creatine can cause this If dehydration occurs, choosing a pre-workout without creatine can help avoid this entirely.

Ingredients That May Cause Side Effects

By identifying what ingredients have a potential to cause side effects, we can begin to better understand these supplements. Below we will go through the ingredients that we found to be most beneficial and the side effects that may come along side them.


Traditionally pre-workout supplements are made around the ingredient caffeine and can found in the majority of them. One of the most widely used ‘drugs’ on the planet, this anti-sleep compound can cause alertness, wakefulness, and vasoconstriction, a narrowing of the muscular wall of blood vessels. Caution should be exerted if not familiar with caffeine, or if you have high-blood pressure. Caffeine’s effects will vary from person to person.

Amino Acids

A range of different amino acids can be found in pre workout supplements. Amino acids are naturally made within the body and super loading them can increase their effects. The most commonly used amino acids are listed below.


Beta-alanine is a modified version of the amino alanine. The main side effect of beta-alanine is a harmless tingling sensation. The way your body responds when too large of a dose is digested at once. Will pass with time. A pre-workout that has a lower dose of this ingredient can help you evade this feeling.

L-Citrulline And L-Arginine

Both of these amino acids are commonly found in pre-workout supplements. These can aid the body by increasing endurance and blood circulation. Regularly prescribe by physicians to help treat certain genetic disorders and a variety of other illnesses. The body naturally makes these, so supplementation of them is seen as relatively safe. Women who are pregnant or nursing are advised to not take citrulline. Other than this, supplementing L-citrulline does not have any known side-effects. Arginine can cause diarrhea and gastrointestinal issues when supplemented above 10g. However, pre-workout supplements do not use nearly enough for this to be a problem.

Yohimbine and Rauwolscine

Used in pre-workouts for their fat burning, mood-elevating, and feel-good properties.These two ingredients have a similar compound make-up, but rauwolscine may be more potent. Be aware that it can cause extreme anxiety in those already predisposed to it. Meaning if you are someone who has issues with anxiety, this is going to amplify that feeling. Dependent on the user, some dizziness or nausea can occur when paired with other stimulants like caffeine.

Trimethylglycine (Betaine)

Trimethylglycine or betaine is safe for most people. Depending on the user, it can be linked to nausea, and upset stomach. Finding a pre-workout with it will be hard, the majority of pre-workouts do not use it, even though it is a very effective performance enhancing ingredient.


Creatine, is one of the most debated and well researched ingredients in the fitness industry. It is safe, healthy for most, and it works! However, you can expect some moderate side effects. Creatine causes the muscles to pull in and hold more water, thus increasing your overall body weight. Dehydration is common, keeping hydrated is a must. Stomach cramps will be a key indicator that you are not drinking sufficient amounts of water. Diarrhea can be a side effect if too much creatine is supplemented at once. Sticking to the recommended pre-workout supplement serving size will help avoid many of these side effects.

Updated:January 22, 2016