Is Pre-Workout Really Safe?

Is Pre-Workout Really Safe?

Pre-workout is my favourite supplement to dig into. And for a good reason. If you have a sample at home, go and have a look at the ingredients. Not only that there’s hundreds of them, they don’t sound familiar at all. At least not to an average customer.

I will try to put together a list of the most common ones, explaining what they are and what they do, eventually drawing a conclusion whether pre-workouts are worth your money and health.

#1 Citrulline Malate

This ingredient is usually listed as number one ingredient on most pre-workouts I came across.

L-Citrulline is an amino acid that is involved in the recycling process of ammonia (urine cycle) and nitric oxide metabolism (nitric oxide is used in athletic performance and cardiovascular function). It is not a synthetic chemical, it’s an amino acid that human body recognises very well and knows how to work with it. It’s naturally available in Watermelons.

Long – term supplementation with L-Citrulline helps to reduce blood pressure and improves blood flow in general, however, no significant results were observed from a one – off dose. There are more positive results with Arginine (more about it below), but by consuming L-Citrulline, we consequently increase Arginine levels because these two amino acids work closely together.

You can supplement with L-Arginine itself but it has a notable side effect, which usually is an upset stomach. L-Citrulline does not have any reported side effects and effectively creates Arginine. This makes a lot better and safer choice.

Now that we got to the basics of these chemicals, I can try to explain what a Citrulline Malate is. It’s not difficult, it’s just a slightly altered version of L-Citrulline, which we can obtain by binding it to a salt of malic acid = malate. Malate plays an important role in metabolising carbohydrates, proteins and fats and is naturally present in fruits, mainly apples.

There are suggestions that malate itself could be beneficial for performance, but unfortunately there is not enough research on that.

Citrulline Malate a very well research component and I’d say there is nothing to worry about with this one.

#2 L-Arginine-A-Ketoglutarate (AAKG)

This one definitely sounds a little more complicated, however, it’s another natural component that human body knows how to work with very well.

It increases the levels of nitric oxide in the body, which we already know is very important in cardiovascular system, mainly by dilating the blood vessels and therefore improving blood flow. This effect can reduce fatigue and increase athletic performance.

I have done a little bit of digging and found an interesting study in the journal called The Journal of Strength and Conditioning. I really recommend checking this journal out if you are interested in researching things more in depth. It’s not as complicated as some medical journals I came across, on the contrary, it’s easy enough to read and draw conclusions for yourself. I am going to quickly sum up the study, but feel free to click on the links and read the whole article yourself.

The result of this study showed significant increase in 1 RM (rep max) on a bench press but showed no change in 1 RM on a leg press, which suggests it has more effect on the upper body than lower body. On top of that, there was no significant progress in muscle endurance (long term muscle engagement), whether it was upper or lower body.

Another study from Journal of the International Society of Sports Nutrition suggests that acute supplementation with AAKG has no positive effects, regardless of the training subjects training status.

The results regarding this chemical are conflicting at the very least. You can find studies with positive results or with no results. I have not come across any negative effects, apart from the L-Arginine possible digestion issues that I already mentioned above. I suppose that’s some good news.

Foods containing natural Arginine are nuts, for example.

#3 Beta Alanine

This is the one that causes the tingling sensation called paresthesia, that I dislike very much. From my point of view, this side effect goes way beyond subtle tingling. I have experienced everything from mild sensation to horrible itching and mood change, probably caused by the irritation. I have also had headaches and a feeling that I could only describe as an impulsive judgment. It felt like drinking a fair amount of Red Bull.

It’s reported to disappear as much as 90 mins after ingesting the supplement and I think this is quite a long time to deal with a side effect like that.

According to the International Society of Sports Nutrition, the paresthesia is caused by consuming more than 800mg in non-sustained release form, which basically means the whole amount hits you all at once. Most pre-workouts contain as much as 3.5g in one serving!!!

Beta Alanine is added to pre-workouts because it increases muscle carnosine concentration. Carnosine is a component found in working muscles and it works a little like a buffer for H+ ,decreasing their accumulation in the muscles. Now, this could be very beneficial, since H+ ions are responsible for the burn you feel during a high intensity exercise. That said, Beta Alanine should theoretically increase endurance capabilities during these activities.

Are the benefits worth the side effect then?

According to the same source (International Society of Sports Nutrition), Beta-alanine appears to:

  • Increase training volume, however, current research does not indicate a benefit on strength gains during resistance training.
  • Enhance high intensity exercise lasting over 60s, with greater effects on open end point exercise bouts, such as time to exhaustion tasks.
  • Improve duration of exercise requiring aerobic energy system (HIIT)
  • Reduce neuromuscular fatigue, particularly in older people
  • Induce a positive effect on military-specific tasks

I don’t understand why the dose in pre-workouts is so high, considering these supplements also quite often contain taurine and caffeine. I think they could cut the dose of Beta Alanine at least in half and still achieve stimulating effects. Especially since the studies show a lack of any side effects, if the dose is kept under 800mg.

For me, personally, the benefits are not worth the side effects. After consuming a pre-workout, I get annoyed and irritated, not being able to concentrate on my session.

Natural sources of Beta Alanine are meat products.

#4 L-Glutamine

Glutamine is a non-essential amino acid which means our body can make it by itself. Actually it’s the most abundant one.

The “L-” in front of the name specifies, which from of Glutamine are we talking about, because this amino acid exists in two forms:

  • D-Glutamine – appears to have no significant function
  • L-Glutamine – the most important form for a living organism

We can actually call L-Glutamine a conditionally essential amino acid, which means that it must be available in higher doses under certain circumstances. This usually means, when the body is undergoing extreme stress, like an illness, injury or surgery – Glutamine is very important for immune function (it’s literally a fuel for immune cells).

At normal times, human body is perfectly capable of making Glutamine itself, but if we experience these extreme conditions, we might get to the point, where we need as much as double the amount our body can produce. Then supplementation comes to place.

It’s also very important for gastrointestinal health because intestines are considered to be the “home of immune system”, if you will.

L-Glutamine is found in majority of animal products and since an average human eats way more animal products than they need, we definitely are not deficient in this nutrient. Just to mention some examples:

  • Eggs
  • Beef
  • Dairy
  • Chicken
  • Fish
  • Tofu
  • Beans
  • Lentils

The exact amount of the L-Glutamine in specific foods has not been studied that well, but a rule of thumb in this case is, the larger the protein content, the more of L-Glutamine is present.

It has been used as a fitness supplement for a while, however, I couldn’t find a study that would significantly prove increase in strength or mass. Studies have been done with active individuals who were given a placebo and L-Glutamine and there has been improvement, nevertheless the result was as good for the placebo group as it was for the group that was taking L-Glutamine.

Most athletes or even just regular gym-goers follow high protein nutrition and, as I’ve mentioned above, any food high in protein most likely contains decent amount of L-Glutamine, so I don’t really see the point of supplementation.

As far as I have found, no side effects were reported from supplementing the body with high doses of L-Glutamine, however, there is definitely lack of research in this area. Since it’s a very abundant amino acid, it’s very likely to be safe. I just don’t know why should we spend money on supplement that our body can easily make AND can be obtained from food we eat frequently.

#5 Tyrosine

Tyrosine is another amino acid that our body can make by itself and it helps with creating other important substances in human body:

  • Adrenaline and Noradrenaline – also called epinephrine and norepinephrine – these two hormones are very well-known for being THE most important in fight-or-flight response. They basically kick in every time you find yourself in a stressful situation.
  • Dopamine – also very well-known, it’s a brain chemical responsible for the feeling of pleasure and reward. It’s also incredibly important for memory and motor skills.
  • Melanin – melanin is a substance that determines the colour of our hair, skin and eyes.
  • Thyroid Hormones – regulate growth and metabolism

So, Tyrosine plays a big role in creating brain neurotransmitters – chemicals that enable nerve impulses to travel around the body. That means supplementing with Tyrosine improves focus and memory.

Studies have been mostly done on people performing cognitive (thinking) tasks at which they outperformed a group on a placebo, or people who were tested on memory tasks, which brought similar results – memory seems to perform better after supplementing with Tyrosine.

It has also shown positive results in people who had experienced sleep deprivation. According to one study, people who have missed a night sleep had been able to stay alert and focused for as much as three hours longer the next day.

The dose is regarded safe for maximum of 0.15g per KG, so let’s look at myself. If I am 60kg, I can have as much as 9g per day. And it should not be for more than 3 consecutive months.

As much as Tyrosine is declared safe, I have to say it’s safe for HEALTHY ADULT PEOPLE! It can have side effects and, most importantly, it can interact with some medications and bodily functions:

  • Thyroid hormones – as I’ve mentioned above, Tyrosine is responsible for creating Thyroid hormones, important for regulating metabolism and growth. Supplementing with high doses of Tyrosine can lead to imbalance in these hormones, especially in young people. Also, according to Department of Health and Human Services, young women between the age of 20 and 30 are more susceptible to Thyroid problems.
  • MAOIs – these are a type of antidepressant, but according to NHS, are not prescribed very often and the reason is their interaction with a lot of food and other medications. However, they are not the only type of antidepressant and I would definitely check with a doctor if you are thinking of taking a pre-workout while using this type of medication. Tyrosine can contradict with them by raising blood pressure dangerously high.

So, as a supplement, you can find it under two names. Either just Tyrosine or N-Acetyl L-Tyrosine. Every brand of pre-workout will show a different one, but the only difference is the dosage because Tyrosine has a higher conversion rate in the body, therefore smaller dose is needed. As I said, it should not exceed 150mg (0.15g) a day per KG of body weight, so check it out for your own body weight.

Remember however, that even though Tyrosine has shown short-term improvement in memory, cognitive tasks and mental performance in general, it has not been proven to improve physical performance during exercise. I think you might be better off with a lot cheaper regular coffee (or caffeine tablets if you don’t like the taste of regular coffee) to get a little boost.


#6 Sweeteners

If you have ever looked up a pre-workout, you must have noticed the funky flavours. Just to name a few:

  • Cola
  • Cherry Cola
  • Apple
  • Watermelon
  • Kiwi
  • Basically any fruit you can think of in any combination you can imagine

Most of the brands out there use Sucralose these days, which is an artificial sweetener and as with anything artificial, especially in the food industry, there is some controversy around.

Sucralose is made from sugar by replacing some hydrogen – oxygen groups with chlorine atoms. It contains no calories and it’s around 500 times sweeter than sugar. Sucralose also doesn’t spike sugar levels in healthy people of a normal weight.

It’s, however, been reported to affect insulin and, therefore, blood sugar in overweight subjects. This is not a huge problem because we eat way too many sugary foods anyway and Sucralose, even if it does cause a little spike, it’s smaller than regular sugar would cause.

The main controversy comes when we try baking with it. People try to use artificial sweeteners in baking recipes because it effectively makes the product less calorific and therefore “healthier”. There have, however, been reports of Sucralose falling apart when heated, interacting with glycerol (main compound of fat) and creating other chemical called chloropropanol (I don’t know how about you but it doesn’t sound very healthy to me), which is suggested to be carcinogenic.

According to FDA, NHS and other organisations, Sucralose have been declared as safe, but you have to decide for yourself how you feel about artificial foods.

Another sweetener I came across was Acesulfame K, which I’ve never heard of before and had to do some digging. The K simply stands for the element Potassium and from what I could find, it’s very similar to Aspartame. That could be considered controversial due to its alleged link to cancer. Despite all this, aspartame has been declared safe and it remains a matter of opinion.

Anyway, back to Acesulfame K and the fact that it does contain methylene chloride, a well-known carcinogen. Just to put things into perspective here, methylene chloride is widely used in some industrial processes, for example:

  • paint stripping
  • pharmaceutical manufacturing
  • glue manufacturing
  • polyurethane foam production

Well, I don’t know what do you think, but these processes are way far from food production. I don’t think I want my food to have anything in common with paint stripping. To be perfectly honest, I have no idea how come this sweetener is not banned yet and how come it can be used in products supposedly helping you with becoming more active and healthy.

Let me know in the comments, I’d love to know what you guys think because I know a lot of people are using these products.

Acesulfame K has one PRO, though 🙂 Unlike Sucralose and Aspartame, it doesn’t disintegrate when exposed to high temperatures but since it already contains a carcinogen anyway, I don’t think it’s much of a PRO 🙂

#7 Colourings

You must have noticed that pre-workouts often have weird bright colours and the one I have always been most concerned about found its way into our foods way too often.

Brilliant Blue FCF

This component has been linked to ADHD = Attention Deficit Hyperactivity Disorder. The link is not 100% but I’d like to be safe than sorry.

It’s present in soft drinks, cakes, sweets mostly marketed as being for children. Since ADHD is mainly a children’s disorder, I think it’s utterly disgusting to add Brilliant Blue into children’s food, however weak the link to ADHD might be.

According to the Journal Science Direct, rats that have been fed this component for two years showed significant growth inhibition, especially males.

Studies have also been done on dogs which distressed me quite a bit. I didn’t know studies like this were done on canines 🙁 Five dogs have been fed this chemical for one year and two died within four months!

OK, they are not humans, so I guess if humans were dying after ingesting Brilliant Blue, we would have probably known about it by now. Still, it doesn’t convince me of total safety.

Another nail in the coffin is that this colouring, even though it’s used in food, is effectively just a dye and it’s a cousin of the stuff that’s used to dye jeans. It used to be obtained from coal tar (yuck) but some sort of oil based component is used nowadays.

In 2007, UK based Medical Journal “The Lancet” also came to a conclusion that Brilliant Blue can be linked to ADHD which effectively led the European Parliament to order the products containing this colouring to introduce a label, warning customers about the side effects and risks. As a response, some companies have replaced the Brilliant Blue in their products (Smarties) for blue spirulina, which is a type of algae that’s been known to have some health benefits.

All in all, toxicology tests show blue colourings as “relatively safe”. If you have to put the word “relatively” in front of safe, I am not convinced.

Brilliant Blue is not present in every single pre-workout but keep an eye on similar controversial ones, for example:

  • Tatrazine (E102) – yellow colour
  • Quinoline Yellow (E104)
  • Sunset Yellow FCF (E110)
  • Carmoisine (E122) – red colour
  • Ponceau 4R (E124) – red colour
  • Allura Red (E129)

The FCF basically means “For Colouring Food”.


My conclusion is 100% decided. I do not and I will not use pre-workout. Ever. Every single component I have mentioned today is either widely available to our body through food and body’s own synthesis, or it’s outright nasty and questionable at the very least.

As always, make the decision for yourself but consider whether your money wouldn’t be spent more wisely on a nice bag of coffee rather than a bag of chemicals and stuff that human body can quite easily make by itself.

I am aware that a lot of people will not agree with me, so I can’t wait to read the comments 🙂 It’s cool, they help people decide too, not just my article so keep them coming!

6 thoughts on “Is Pre-Workout Really Safe?”

  • Hi Silvie,

    Well that’s certainly put the cat amongst the pigeons for me.

    I had never previously taken pre-workout until last year.

    In fact, throughout my many years of training I have pretty stuck with creatine and protein powder (please don’t tell me they’re bad for me too, LOL. Although I have cut out the creatine for the moment).

    I’ve always recovered fairly well even with fairly intense training 5-6 days a week.

    However, I kicked things up a notch last year in training for the Spartan race that I completed in June. From March 2019 until a few days before race day I was pretty much training 7 days a week, and a very different type of training from what I normally do.

    In fact, I’d often ended up training a couple of times a day, totalling around 3 hours (talk about overtaining).

    So, I started taking pre-workout, and often twice a day, just to give me a boost in order to train.

    You’ll be pleased to hear that I’ve taken the foot of the gas on the working out, and I was definitely in overtraining mode coming into lockdown, so it’s done me good to have a break here-and-there.

    I’m actually currently working out less than I ever have before, but still reaping the benefits. Who would have thought that someone like me would only train 4 times a week, for about 50 minutes at a time (but trust me it takes some getting used to – I’m always wanting to crank out a few hundred push ups or chin ups at home, because I don’t feel I’m doing enough, but I resist, LOL).

    With that said, the one thing that has stuck with me since last year is that I continue to take pre-workout.

    I knew there were certain ingredients that I probably shouldn’t be taking, especially as I completely gave up sugar last year – I did not know about the sucralose. However, this actually explains a lot in terms of my mood sometimes.

    I can totally relate to the tingling sensation and itching, and this was something that started to bother me. I even felt a “kind of buzz” often, something that you’d probably associate with harmful, recreational drugs.

    Hmm, well you definitely given me a lot of food for thought here.

    I guess as I’m training a little less at the moment this may be the perfect time to knock the pre-workout on the head.

    A fantastic read Silvie and definitelysomething that I needed to hear.


    • Wow, you really do sound like someone who doesn’t know when to stop 😀 I wish I was the same sometimes. I struggle with getting myself up and running, going to the gym, especially now when the weather is miserable again.

      You are definitely right about overtraining 🙂 I think it might have been you case 🙂 I am glad you realised how bad overtraining is for the body, especially when you are young because you don’t immediately see the bad side – your not in too much pain, your energy is high up when you are in your 20s…

      Well done on giving up sugar!!! I don’t use sugar either, I mean, occasionally I do have a treat or a dessert when I am out for dinner but these are occasions. I do use maple syrup and honey in my porridge though, this is my only sin. But I do not sweeten my drinks, I don’t drink fizzy stuff. If I buy a juice, it’s only natural and pure, not with added sugar.

      And oh my god, definitely agree with the “recreational drug” buzz feeling while taking pre-workout!!! It scared the crap out of me, I hate all drugs, never understood the reason why would anyone in their sound mind touch them so obviously this buzz made me feel incredibly uncomfortable. A fitness product shouldn’t do this to you!!!

      And about Protein + Creatine? You probably have done a lot of research yourself since you work out 🙂 I am interested to see your opinion but I think they are completely harmless. They are both natural ingredients and our body is not capable of creating enough, especially creatine! Supplement is the only choice but creatine is well studied compound over a long time so I think we are ok with this one. Protein? Love it and will keep using it. I’ve recently switched to a new Vegan one which comes in Zero Plastic packaging, based in the UK, too 🙂 I will be writing an article about them but give a follow on Instagram if you want 🙂 I think they are worth the effort and money if you are interested in something sustainable.

      • Oh trust me Silvie, my 20s are well and truly behind me, LOL.

        But, I still regularly train with people pretty much half my age and I’m proud to say they often have trouble keeping up with me.

        My main problem with exercise (as well as other areas of my life too I guess) is I tend to get very obssessed, I think nothing of working out for hours without really considering the consequences.

        Once I have something in my mind, then I find it hard to turn off.

        With that said, I’ve actually been really good following the first lockdown we had in the UK and have exercised pretty sensibly ever since.

        I’ve even settled on just doing a quick 30-35 minute workout in the morning followed by a nice , relaxing walk now that we’re in second lockdown. That’s pretty controlled for me, LOL.

        I have to thank you Silvie, as I’ve actually stopped taking pre-wprkout since reading this article.

        I’ll admit the first couple of days in the gym were a struggle, but I got used to it, and now I’m working out a little less, and with much lighter weights, so it’s not an issue. So, I think we can safely say, that i’m well and truly done with pre-workout for good.

        Yes, I totally agree with what you say about Protein and Creatine, although the reason I’ve stopped taking creatine is because of water retention. This is a potential side effect, and although it wasn’t a massive problem for me, I definitely look far more definied since I gave it up.

        Yep, just read your review of the new vegan protein shake – if you say it’s okay, it gets the thumbs up from me too.


        • It’s amazing to have this sort of mindset that drives you to do whatever you have decided to do. Some people call it an obsession, some call it motivation 🙂

          I do believe you made the right choice with pre-workout because at least your head is clear and even if you do lower weights, at least you do it properly. It’s not always about lifting heavy but doing it right. I do like your lockdown workout plan, I have approached similar strategy, I have started designing little HIIT workout for my morning on little Canva templates and I have to say, it’s a lot of fun, I’ll be posting them to my IG and using it as a guide for myself, too. At least they will be stored in one place and easily accessible 🙂

          It’s however become a little difficult with walks since November is not the best month to spend outdoors 🙂 But so far it has been quite kind.

          Keep it up! Only 3 weeks for the gyms to open 😀

  • I am not a fan of supplements, never was and most certainly never will be after reading your article. I have always worked out using weights and love to run since I was 15 years old. There are way too many companies selling garbage to the public on the belief they will get healthier, stronger and live longer which couldn’t be farther from the truth. These companies are out for the buck, not to make you healthy. My Grandmother always told me, “If you want to grow up to be healthy and strong then eat real meals and stay away from man-made garbage.” Her words hold truer today than they ever did.

    Did you know sugar used to be considered a drug when it first came out and cost a fortune? That is why we still say today, “he’s high on sugar” when a kid eats too much sugar products. Today we get overweight because they put sugar in everything including milk. Just like sugar, a lot of chemicals will slowly be accepted into the food group because not enough people are paying attention to it.

    I enjoyed this article very much because and it’s nice to see someone taking a real true look into these nasties that are going on the shelf to consume. Thank you

    • Thank you for the kind words 🙂 I had no idea about the sugar, maybe I should do some research and write an article. I think I would enjoy digging up information like that 🙂

      I do have to disagree with being against all supplements, though. Not all of them are bad and as the name suggests, they are only supplements. They should help your diet rather than replace it. But some of them are not necessary because our body knows how to create certain amino acids contained in these products. Quite often we do not need extra. But some people also have issues and conditions which make it difficult for them to absorb some nutrients or their diet just don’t give them enough of a specific compound. It that case, supplementation could be a big help. Also, you don’t have to be an athlete to see that the protein intake from regular meals might not be enough, especially when you are trying to cut down on meat consumption (like me). And because I cannot practically eat as many beans and legumes to meet my goal, I use Vegan and sustainable supplement created in a small batch.

      I wouldn’t demonise all companies, some of them are actually trying to do some good and make a positive impact on the planet 🙂

      Pre-workout, however, I think is evil 😀 Definitely no argument there.

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