As someone who's seen it all when it comes to supplements, I couldn't resist giving GAT Sport NITRAFLEX pre-workout a whirl. 

I could’ve been dismissive right from the start, seeing how this entire thing is one huge proprietary blend, but I thought, how about we try and work it all out?

After sweating it out for three weeks straight, I'm here to deliver you my GAT Sport NITRAFLEX pre-workout review - no holds barred.


  • Excellent price-to-value ratio
  • Has a wide array of flavors to choose from
  • Offers a substantial caffeine dose
  • Solid choice of ingredients
  • Updated the formula to exclude artificial flavors


  • Use of proprietary blends
  • It may cause tingles
  • Mostly underdosed ingredients

GAT Sport NITRAFLEX Pre-Workout Review

While I’m an avid hater of proprietary blends, GAT Sport pre-workout is a product I’d rate higher than some non-proprietary, fully transparent formulas.

Don’t get me wrong, I still wouldn’t recommend GAT NITRAFLEX pre-workout, but I wouldn’t say that this is a lousy product, either.

The GAT NITRAFLEX will definitely work, as its caffeine content is quite commendable, and while I can’t say I saw or felt any testosterone-boosting ingredient effects promised by the marketing team, I also can’t say the product didn’t feel good to use.

Let me break it all down for you.









Overall Rating


My Ratings Explained

While I do like ingredient choices in GAT Sport NITRAFLEX pre-workouts, I simply can’t score it higher than this because I don’t know the exact dosages for any of them. The only ones I do know for certain are caffeine and boron, and I don’t really care for the latter.

Effectiveness-wise, I can’t lie to you and say that it doesn’t work. Anyone who does is either lying or is incredibly tolerant of stimulants, which I’m neither. I also can’t say it blew my socks off, but it did help me.

And finally, the strongest suit of GAT NITRAFLEX pre-workouts is the price. With a single serving costing less than $1 (although some places have it priced higher), the GAT Sport NITRAFLEX pre-workout is part of a small and exclusive club you don’t come around often these days.

Key Details

Servings Per Container


Price Per Serving


Unit Count (Ounces)

10.6 Oz



Calories (Per Serving)


Carbohydrates (Per Serving)


Calcium (Per Serving)


Sodium (Per Serving)


Potassium (Per Serving)


Will My Performance Increase?

GAT NITRAFLEX pre-workouts did elevate my performance. Not by a large margin or across the board, but I did feel better coming into each workout. I expect the same will happen for you.

After my three-week test run, here's what I observed.

GAT NITRAFLEX Pre-Workout Performance Graph

First, the energy boost is real. Within 15-20 minutes of taking it, I’d feel an energy surge gradually ramping up. This has happened every single time, and while three weeks isn’t a lot of time, I didn’t feel the effects become less noticeable as time passed. 300+ milligrams of caffeine will give you a kick every single time.

Now, I’m far past weekly weight progressions, but I did manage to get in a few extra reps here and there, so I’d say that my endurance and strength were also up a few notches.

As for focus - it was there. I’m rarely in need of a focus enhancer, but I did notice that zoning in on my form was much easier with NITRAFLEX pre-workout than without it. So, nice improvements in this area, too.

As for the pump, I didn’t notice any difference. I’d still get full and firm after only a few exercises, but that happens regardless. I really wouldn’t call this one a pump-booster.

How Will I Feel Post-Workout?

My post-workout experience with the GAT Sport NITRAFLEX pre-workout was quite alright. In fact, it was one of the better post-workout experiences I had in a while, and I don’t see why you wouldn’t feel the same.

My energy would linger at a high level for a few hours, so I’d usually just go do some work after I’m done with the gym. Now, I can’t say I was the most productive I ever was, but I also didn’t want to hit the sofa right away.

On an even better note, I didn’t crash a single time. I had 12 sessions these past three weeks without a single post-workout issue, which is excellent.

What Are The Possible Side Effects

GAT NITRAFLEX pre-workout is generally considered safe, but a few potential side effects could occur. Most commonly, people experience:

  • Skin tingling
  • Caffeine jitters
  • Insomnia
  • Gastrointestinal discomfort
  • Elevated BP and heart rate

Thankfully, only one of those was an issue for me - skin tingling.

As you probably know, beta-alanine tingles are a common side effect, and while they are annoying, they are completely harmless. 

For me, tingling occurs if I just think about beta-alanine, so I’m definitely not the benchmark for it, but if you’re as sensitive as I am, expect 20 to 30 minutes of itching.

What Flavors Are Available And How Do They Taste?

GAT Sport NITRAFLEX pre-workout comes in 13 different flavors:

  • Blue Raspberry
  • Fruit Punch
  • Grape
  • Green Apple
  • Black Cherry
  • Watermelon
  • Patriot Blast
  • Lemon Tea
  • Beach Blast
  • Blood Orange
  • Blackberry Lemonade
  • Strawberry Mango
  • Guava Dragonfruit

While I was doing my GAT NITRAFLEX review, only two of these 13 were available on Amazon, so my choices were quite limited. That said, I did get both Black Cherry and Blue Raspberry.

The rest of the flavors were available on the website, but these seemed right up my alley, so it really didn’t matter as much.

Anyway, both Black Cherry and Raspberry were quite nice. Both were very tangy and somewhat intense, but I wouldn’t call it overpowering.

The biggest thing for me was the lack of a lingering aftertaste, so overall, I liked the GAT NITRAFLEX taste.

Also, I must say there is a certain chemical hint to both, and while that doesn’t really bother me, I know many don’t share my feelings.

Finally, both dissolved and mixed in water quickly and easily, leaving little to no residue on the bottom of my shaker.

Is It A Fair Price?

I’d say that GAT Sport NITRAFLEX pre-workout is a fairly priced product all things considered.

While you could get very similar effects by simply using caffeine pills and some citrulline on the side for a lot less, compared to some other products on the market, GAT NITRAFLEX pre-workouts do have a pretty fitting price tag.

That said, I would much rather spend extra and know precisely what and how much I’m getting. In fact, I’d gladly spend twice as much if I’m getting what I want and how much I want.

NITRAFLEX Pre-Workout Key Compounds

Who Is It Best For?

GAT Sport NITRAFLEX pre-workout is best suited for those who don’t really care about the better muscle pumps and are in it just for the caffeine kick on a budget. That’s how I understand their ideal customer.

But as far as my GAT NITRAFLEX review verdict is concerned - I wouldn’t call this product best for anyone. 

As I just said, you can get your caffeine kick from simple caffeine pills you can get for pennies, so I can’t say I understand why anyone would pick a semi-good pre-workout over pure caffeine, but to each their own.

Who Is It Not Good For?

My previous verdict aside, the only ones GAT NITRAFLEX is genuinely not good for are:

  • People with pre-existing heart issues like high or low blood pressure
  • People who are caffeine-sensitive
  • People suffering from psychiatric or epileptic disorders
  • People using specific medications
  • Pregnant or nursing mothers
  • People with hormone-sensitive conditions

Aside from that, I'd say this isn't the formula for stim-chasers or those who love to double-scoop.

Also, unlike most other pre-workout products, GAT Sport NITRAFLEX comes with 200 mg of Boron, which could cause some additional issues in certain individuals.

Other Online Reviews

Online Store

Star Rating

Number Of Reviews




Brand Website



Average Online Rating



Tips For Increasing Performance Using GAT Sport NITRAFLEX

One thing I learned while I was performing tests for my GAT NITRAFLEX review is that a few things could help optimize how you use this product. 

First, watch your serving size. This is a strong pre-workout so don’t double-scoop under any circumstances. The caffeine content of NITRAFLEX is quite high, so you might even want to start with half a serving to gauge tolerance.

The rest of the formula is already quite underdosed, so splitting the dose in half won’t make much of a difference.

Also, pairing NITRAFLEX with a light carb source can help bring the energy up a bit further. 

For example, I sometimes drink unsweetened cranberry juice before training. That way, I can get an additional energy boost and some antioxidants without troubling my stomach with a heavy meal, so try that if you want.









Overall Rating


Ingredients - Effectiveness & Amount

Key Ingredient


Clinically Effective Dose


Caffeine per serve

325 mg

3-6 mg/kg

Very effective

Citrulline per serve


6-8 g

Highly unlikely



500-2000 mg

Moderately effective



100-200 mg

Moderately effective


Caffeine is a central nervous system stimulant that plays the most pivotal role in pre-workout supplements. 

It mobilizes fatty acids from fat tissues, making them available for energy, and also blocks the neurotransmitter adenosine, leading to increased alertness and wakefulness (amongst many other things). [1]

In the case of GAT Sport NITRAFLEX, we have a robust 325 mg dose, which could lead to:

  • Increased alertness and wakefulness
  • Elevated energy levels
  • Enhanced athletic performance
  • Improved concentration and focus


Citrulline is an amino acid found in pre-workout formulas. It is a known nitric oxide booster known for its potential benefits in promoting blood flow to working muscles.

Once ingested, citrulline is converted to another amino acid, arginine, which subsequently increases nitric oxide levels - a compound known to dilate blood vessels. 

This vasodilation can lead to:

  • Improved nutrient delivery
  • Enhanced exercise performance [2]
  • Reduced muscle fatigue

However, citrulline efficacy is dosage-dependent. Ideally, you’d need 6 to 8 grams of citrulline, and since there are probably only 2 grams of citrulline in this "Vasoactive Arginase-Regulating NO Precursor Complex", its effect is highly questionable.


Tyrosine is a non-essential amino acid that plays a role in the production of neurotransmitters like dopamine, norepinephrine, and epinephrine. 

In the context of pre-workout supplements, tyrosine is believed to enhance cognitive function, particularly under stress, delay the onset of mental fatigue during exercise, and, according to research by Laura Steenbergen, positively impact cognitive flexibility. [3]

Yet, once again, a correct dosage is paramount for tangible effects. In this case, I’m assuming you’re getting 500 mg based on its place in the proprietary blend list, but that’s nothing more than an educated guess.

However, if that’s true, that’s the lowest efficacious dose according to data.


Finally, we have L-theanine, one of many beneficial amino acids found in tea leaves.

In synergy with stimulants like caffeine, theanine can help to smooth out energy jitters, promoting a focused and relaxed state. In other words, it can help you get energized without the accompanying anxiety.

And yes, once again, we don’t know the exact dosing. I had to guess, I’d say we’re getting 50 mg, which is half the minimum efficacious dose.




Clinically Effective Dose




250-500 mg



50-300 mg

Synephrine/Bitter Orange Extract


10-20 mg t.i.d.


Yes, undisclosed quantity

100-300 mg

Mildly effective

NITRAFLEX Pre-Workout Supplement Facts

GAT Sport NITRAFLEX also contains DMAE (Dimethylaminoethanol bitartrate), a compound often integrated into pre-workout supplements and nootropics due to its potential cognitive-enhancing effects. 

Some data suggests that DMAE may increase the production of acetylcholine, a neurotransmitter essential for memory, concentration, and muscle contraction. [4]

Due to its mildly stimulating nature, some users even report heightened alertness and energy, but the scientific backing for these claims is still scarce.

And yes, we don’t know the exact dosage for this one, either. However, I’m assuming it is somewhere around 100 mg.




Clinically Effective Dose



Yes, undisclosed quantity

3.2-6.4 g/day

Highly unlikely



3-6 g


Yes, undisclosed quantity

1.5 g




1.6-6.4 mg/kg



300-500 mg



300–600 mg

Huperzine A


50-200 mcg

Choline Bitartrate


500-3000 mg



3-5 g/day



1-10 g



5-10 mg



500-2000 mg



3-6 g





Yes, undisclosed quantity


Highly unlikely


Yes, undisclosed quantity

250-1500 mg

Highly unlikely


Yes, undisclosed quantity

50-1000 mg

Highly unlikely

Boron Citrate

200 mg

3-10 mg

Highly unlikely

In addition to the aforementioned components, GAT Sport NITRAFLEX harbors beta-alanine - the most abundant compound in the "Acute Energy, Focus, Intensity, Neuromodulating, Endurance Complex" blend.

Beta-alanine is known for its role in buffering acid in muscles, potentially reducing fatigue during high-intensity exercise, but at this dose (which is probably around 1.6 grams), it just won’t work. 

Nitrosigine, a well-known nitric oxide booster,  is another addition to this formula, included to improve blood flow and enhance exercise performance alongside citrulline. And just like citrulline, my guess is Nitrosigine is also underdosed. 

Resveratrol, Pterostilbene, and Rauwolfia vomitoria root extract are also in here, as they are believed to aid in cardiovascular health, athletic performance, and energy and focus. That said, research on all of them is not promising. [5]

Lastly, the formula provides 200mg of Boron citrate, included as one of the more popular natural testosterone boosters.

Some studies have shown some massive free testosterone increases over a short period, but there are only a handful of them, and their study pools were quite small, so I wouldn’t go trusting them blindly. [6] Also, a 200-milligram dosage is far greater than one should take, according to current data.

In fact, I went to the lab and checked my total and free testosterone levels both before and after my GAT NITRAFLEX review, and they remained unchanged.

How I Felt When I Took GAT Sport NITRAFLEX Pre-Workout

Here’s a brief timeline of how I felt when I took GAT Sport NITRAFLEX pre-workout.

Within 15 Minutes

After taking NITRAFLEX, it didn't take long before I sensed its effects. 

My palms felt quite a bit sweaty, I felt a blood rush, and there was a light tingling sensation, courtesy of my arch-enemy - beta-alanine.

The tingling was especially noticeable around my ears and hands, as well as my behind. Thankfully, it would usually go away after 30 minutes or so.

As for the energy boost, I wouldn't call it an instant surge, but there was a notable shift in how I felt. The best I could describe it is if there was a volume  knob, I was slowly turning up.

Within 60 Minutes

By the time sixty minutes passed, the full force of the NITRAFLEX powder was evident. 

I was right in the middle of my workout, I felt awake, attentive, and even maybe a tad more eager to lift than usual. I don’t know if this was a placebo because I liked these proprietary blends more than others, but not one of my sessions on NITRAFLEX felt lazy or forced.

Now, don’t get me wrong, the exercises didn't necessarily become easier. However, I was more present, more willing, and more in tune with each movement. 

This truly was a pleasantly surprising experience.

After 6+ Hours

As I said earlier, not once did I crash when taking GAT Sports NITRAFLEX pre-workout. 

Most days, my workouts would start between 3 and 4 PM, and while I was definitely tired come nighttime, I still felt relatively alert without any overpowering feelings of fatigue or exhaustion. 

Sure, I could go to sleep at any moment, but staying awake didn’t feel like a chore. I could easily watch a movie without dozing off, which is something I do from time to time, so kudos to GAT Sports.

One thing I will say is that I did try to take a nap three hours after taking NITRAFLEX, but that really didn’t go according to the plan. I think I managed to doze off for a few minutes after lying in bed for two hours, so definitely don’t use this one before bed.

How Does It Compare To Other Pre-Workouts?

GAT Sport NITRAFLEX Vs C4 Pre-Workout

GAT Sport NITRAFLEX has more than twice as much caffeine compared to C4, so it is a better option if you are looking for something that’s stimulant-heavy.

Also, GAT should give more of a pump than C4, but I really can’t say I noticed a significant difference.

The way I see it, the biggest difference between the two is the ingredients themselves. 

Neither of these does the dosing right, but at least the GAT Sport did a better job of picking the ingredients. That said, C4 is a bit more transparent with the ones they've got, so that’s something worth mentioning.

Flavor-wise, I may have to side with C4, but the difference isn’t massive, believe me.

Overall, I’d say GAT Sports NITRAFLEX takes the crown.



  • Far more potent
  • Better ingredient selection

C4 Original

  • Better-tasting
  • Likely contains more citrulline

GAT Sport NITRAFLEX Vs Total War Pre-Workout

Total War pre-workout is a considerably better option than GAT Sport NITRAFLEX. In fact, Total War is one of my favorite budget-friendly products on the market.

It’s not the best formula out there, and more than a few of its ingredients could be dosed better, but it works. It’s got 320mg of total caffeine, 4 grams of pure citrulline, 3.2 grams of beta-alanine, and a few other notable ingredients that might help you out.

One thing I will say is that Total War does tend to get really clumpy, unlike NITRAFLEX. I’ve seen instances of Total War pre-workout being just one giant rock-like structure in a jar, so keep that in mind.

Finally, NITRAFLEX pre-workout is slightly less expensive than Total War, but since they’re both super budget-friendly, I’d say this difference is negligible.


Total War

  • Better overall formula
  • Excellent price-to-value ratio


  • Does not clump
  • Less expensive

Related Article - Total War Pre-Workout Review

What We Have Taken Into Consideration For Giving You A Final Verdict

Why would you trust anything I say?

My Expertise In Supplements

Over the years, I've delved deep into the world of dietary and performance supplements, both personally and professionally. As a rookie, I made a few mistakes that made me realize early on that most supplements aren’t really good for you.

So, my knowledge base isn't just rooted in textbook study or passing trends. It also includes hands-on experiences, testing numerous products, and engaging with other folks in the field. 

When I analyze a product, whether that’s a pre-workout or something else entirely, I try to offer my comprehensive understanding of ingredient interactions, optimal dosages, and even potential side effects so everyone can understand what they’re getting into.

What helps me do this is my background in pharmacology. While I never got my diploma, I spent three years studying pharmacology at the University of Belgrade.

And as a cherry on top, this year, I became a certified sports nutritionist.

Reviewing Other Products

My experience in reviewing products doesn’t just revolve around pre-workouts. To be fair, pre-workouts are my main focus, as they’re the ones that are usually not worth your money, but I’ve also dabbled in other dietary supplements. 

I’ve also spent countless hours researching all sorts of ingredients and compounds in order to understand why they’re used when they’re used. So, when I talk about how something measures up, it's because I've been there, done that, and I know more than a thing or two about it. 

And I’m not just sharing my opinion. I’m backing all of this up with science.

Frequent NITRAFLEX Pre-Workout Questions

Does NITRAFLEX pre-workout have testosterone?

NITRAFLEX doesn't have testosterone, but it comes with boron, which is anecdotally known as a testosterone booster.  

Is Gat NITRAFLEX banned?

No, NITRAFLEX isn't banned and doesn't come with banned substances. It's just a stimulant-containing product that aids your overall workout.

Will NITRAFLEX pre-workout show up on a drug test?

No, NITRAFLEX does not test positive in a drug test, so you can use it in sporting events and competitions.

Does NITRAFLEX pre-workout have creatine?

No, NITRAFLEX does not contain creatine. If you wish to consume creatine, you'll have to supplement it separately, as this is a creatine-free product.

Final Verdict

On the one hand, one could say that NITRAFLEX is a great all-around formula, considering its efficacy. However, upon closer inspection, it is quite evident that most of the stuff in this formula is either underdosed or is just barely effective.

Apart from caffeine, not a single ingredient in here is dosed properly, and that says a lot about the product.

So, no, NITRAFLEX pre-workout supplement isn't something I'd gladly recommend. However, if you just take a peak down below, you'll see a product I would recommend in a heartbeat.

we recommend this instead!

Transparent Labs BULK Pre-Workout







Overall Rating




Last Updated on October 29, 2023

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Andrew White

Andrew White is the co-founder of Garage Gym Pro. As an expert fitness professional (gym building nerd) with over 10 years of industry experience, he enjoys writing about everything there is to do with modern fitness & the newest market innovations for garage gyms. When he isn’t testing out products for his readers, he’s usually out surfing or playing basketball.