Nitraflex Pre-Workout Review (2025): Excellent Pump and Minimal Tingles

Are your workouts running you ragged? Is your normal cup of coffee before a workout just not cutting it anymore? If that’s the case, this GAT Sport Nitraflex pre-workout review will give you the rundown on this powerful pre-workout formula. 

Nirtraflex may even give our top pick for the strongest pre-workout a run for its money. It packs a serious punch with 325 milligrams of caffeine and a warning label urging you not to take it within five hours of bedtime. So if you’re on a morning workout schedule (and looking for more energy), read on. 

When we test supplements, our testers follow an in-depth supplement testing methodology and score different categories on a 1-to-5-star scale that you’ll see throughout the review. These categories include:  

• Price per serving: Where does the price fall based on similar pre-workouts? 
• Formulation: Does the brand use proprietary blends or have full transparency on ingredients and dosage?
• Taste: How does the pre-workout taste and does it match the flavor advertised?
• Solubility: Does the powder fully dissolve when using the recommended serving size?
• Side effects: Does the pre-workout cause tingling, digestive problems, or a major crash afterward? 
• Third-party testing: What third-party lab tests this formula, if any?
• Customer service: Are the policies fair and is it easy to get in touch with support staff?

Medical disclaimer: This article is intended for educational and informational purposes only. It is not intended as a substitute for medical advice. For health advice, contact a licensed healthcare provider. GGR also recommends choosing a product that has been third-party tested for quality.

We’ve Taste-Tested Over 60 Pre-Workouts

Your friends at Garage Gym Reviews are certified nutrition coaches and personal trainers. We use our collective expertise and fitness industry knowledge when we select, test, and review supplements to provide the most unbiased take. Plus, we call on industry experts from our expert panel to help inform our decision making.

For this GAT Nitraflex review, GGR social media manager and expert product tester Brittany Combs put the pre-workout supplement to the test for both strength and conditioning workouts. 

Nitraflex Pre-Workout

Nitraflex Pre-Workout

GGR Score: 3.71

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Product Highlights

• 325 mg of caffeine 
• 13 flavor options 
• 15- and 30-serving tubs
• No creatine

Pros & Cons

Pros

• Subscribe and save options
• Affordable price tag
• Forumatled with cognitive enhancers

Cons

• Caffeine content not suitable for everyone
• Contains sucralose

Bottom Line

Nitraflex Pre-Workout offers an affordable and powerful pre workout formula. It features 325 mg of caffeine per serving, which is over 3x more caffeine than the average cup of coffee. The website notes not to combine with other caffeine products or take more than one scoop per 24-hour period.

A Quick Look at GAT Nitraflex Pre-Workout

GAT Sport is a brand that offers a wide range of dietary supplements. You’ll find protein powders, amino acids, creatine, joint support supplements, mass gainers, and testosterone boosters. 

You may even notice that GAT Sport offers multiple pre-workout supplements including options that contain creatine (Nitraflex+C), are formulated with fat burners (Nitraflex Burn), and offer nootropic formulas (Pumptropic). For the purposes of this Nitraflex review, however, we’re going to stick with the Nitraflex Advanced pre-workout. 

Before You Buy

• Nitraflex Advanced comes in 15- and 30-serving containers.
• Caffeine content is triple the average 8-ounce cup of coffee. 
• The GAT Sport website warns not to take this pre-workout if you take medications like antidepressants or anti-inflammatories. 

Is Nitraflex Pre-Workout Worth It?

If you’re looking for a pre-workout that will give you a kick in the pants to kick-start your workouts, this Nitraflex formula might be worth it for you. It offers high levels of caffeine, so it won’t be worth it for folks looking for a stim-free pre-workout drink. 

Not only does Nitraflex offer tons of caffeine, it’s also affordable compared to some of the best pre-workouts available on the supplement market. Our testing methodology notes that perfect 5-out-of-5-star scores are reserved for pre-workout products that offer a price per serving of $1 or less. This Nitraflex pre-workout comes in at $1.17 per serving, so this earns a 4.5-out-of-5-star rating because it’s so close to that $1 mark. 

Nitraflex Pre-Workout Specs

This information is from the manufacturer’s web page for Nitraflex Blue Raspberry flavor. There may be minor discrepancies for other flavors or information from other retailers. 

Experience Using Nitraflex Pre-Workout

Expert product tester and GGR social media manager, Brittany Combs says Nitraflex is overall a solid pre-workout. She approves of the taste and texture, and says it helped her get moving in the gym. 

Brittany suggests eating something beforehand to avoid any feelings of nausea. “I would not recommend taking this on a completely empty stomach,” she says—duly noted, Brittany! 

Additionally, there is a warning label on the container (and on the website) that advises you not to use Nitraflex if you’re pregnant, nursing, or trying to become pregnant. The warning label also says not to use it if you have a medical condition including (but not limited to) heart, liver, kidney, or thyroid disease; epileptic disorders; high or low blood pressure; and cardiac arrhythmia. 

The warning continues to advise against use if you take prescription or non-prescription medication of any kind including inhibitors, antidepressants, aspirin, or non-steroidal anti-inflammatory drugs. 

Price Per Serving

Nitraflex comes in either a 15- or a 30-serving container. While both options offer affordable pre-workouts, the larger container gives you a better bang for your buck. 

Purchasing the 30-serving option will run you $34.99, which works out to be $1.17 per serving. With the 15-serving container you pay $24.99, which equates to $1.67 per serving. 

Nitraflex Ingredients

The formulation for this Nitraflex Advanced pre-workout earns a 3-out-of-5-star rating. While the label doesn’t explicitly say it’s a proprietary blend, the label does group ingredients together so you can’t quite tell how much of each ingredient is in one serving (which we don’t find ideal). 

For example, the pre-workout features a “Vasoactive Arginase-Regulating NO Precursor Complex” featuring a mix of L-citrulline, inositol, stabilized arginine silicate (as Nitrosigine) resveratrol, and pterostilbene totaling 3,700 milligrams. 

Nitrosigine¹ is a blend of arginine and amino acids that helps promote nitric oxide and blood flow, which may help improve the “pump” feeling during your workouts. 

There is also an “Acute Energy, Focus, Intensity, Neuromodulating, Endurance Complex” with 2,621 combined milligrams of beta-alanine, L-tyrosine, caffeine anhydrous, DMAE bitartrate, L-theanine, and Rauwolfia vomitoria root extract. 

The endurance complex does sound promising because research shows² that L-theanine and caffeine together may help boost mental focus and mood, which is an excellent combination for workouts. Although caffeine is listed in this combination formula, at the bottom of the nutrition label it’s clearly stated there are 325 milligrams of caffeine per scoop, which is comparable to just over three cups of coffee. 

Some of you may also like knowing there are 200 milligrams of boron citrate in this formula. Nitraflex markets its formula as a natural testosterone-enhancing complex (aka boosting your free testosterone), however there is limited evidence³ that boron actually boosts testosterone levels, even temporarily. 

Nitraflex is sweetened with erythritol, which provides sweetness with few calories. It’s also sweetened with fructooligosaccharides⁴, which is a naturally occurring fructose extracted from plants like artichokes, bananas, chicory, and onions. It’s known for probiotic effects and may help reduce constipation. 

GAT Sport could improve the formulation and label by calling out each ingredient and the exact dosage. Our experts prefer to see pre-workout ingredients individually listed versus lumped together. 

Taste and Solubility 

There are 13 flavors to choose from when buying Nitraflex. Our expert tester and GGR social media manager Brittany Combs tested the Blue Raspberry flavor and enjoyed the berry-like taste. She even says, “It’s delicious.” 

Brittany gives Nitraflex pre-workout a 5-out-of-5-star rating for flavor. “It was definitely sweet, but not offensively sweet, and was very easy to get down,” she says. 

Brittany notes that the label recommends mixing the pre-workout powder with cold water, which she did and had no problems with. For solubility, Nitraflex earns a 4-out-of-5-star score. 

She says if you let it sit in your shaker for a few minutes there will be some separation. “But as soon as you swirl the water around it goes back to being mixed correctly. There is no residue left in my shaker after drinking it either,” says Brittany. 

Side Effects

Nitraflex contains beta-alanine, which is an ingredient behind the tingly feeling you may get with some pre-workout formulas. Beta-alanine is a non-essential amino acid with evidence to support its ability to improve muscle fatigue⁵ (and fairly conflicting research around its ability to enhance athletic performance). 

Most research⁶ around this enhanced performance claim looks at doses of about 6 grams. The beta-alanine ingredient is listed within the “endurance complex,” so we actually don’t know the specific dosage of beta-alanine. 

Brittany says she feels a slight tingle when using Nitraflex, “But it doesn’t give me the jitters or make me want to claw my face off like some other pre-workouts have done in the past,” she says. This leads us to believe it’s a fairly low dosage of beta-alanine. 

“And it certainly packs a punch in the energy department,” she says about the 325 milligrams of caffeine. And for this reason, Nitraflex earns a 4.5-out-of-5-star rating for its punch. It’s worth noting that the warning label on the package explicitly says not to take it within five hours of bedtime, so you’ll want to plan accordingly. 

Brittany mentions that the high caffeine dosage sent her to the bathroom within the first hour of consuming the pre-workout. So, if you’re someone with a sensitive stomach after a cup of coffee, be warned that this pre-workout may have you beelining to the bathroom. 

Legions Pulse vs Nitraflex Pre-Workout

Legion Pulse Pre-Workout

Legion Pulse Naturally Sweetened & Flavored Pre-Workout

GGR Score: 4.2

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BOGO 75% off sitewide See Details

Product Highlights

• 100% nature-based
• Free from added sugar, food dyes, and other chemicals
• Full refund if not satisfied
• Can get with or without caffeine
• 15 flavors available

Pros & Cons

Pros

• All-natural ingredients
• Free from dyes and chemicals
• Naturally sweetened
• Intended to avoid the dreaded crash
• Full refund if not satisfied
• Can get with or without caffeine
• 15 flavors available

Cons

• Natural sweeteners make for a different taste—it may not be your cup of tea
• Only 21 servings per tub

Bottom Line

Formulated with all-natural ingredients, each of which are present at a high level, Legion Pulse's stim-free pre-workout formula is a fan favorite. If you’re trying to avoid artificial flavors and chemicals, this may be a good choice.

Legion Athletics Pulse pre-workout is comparable to Nitraflex pre-workout when it comes to the high-caffeine content. Legion Pulse actually contains more caffeine at 350 milligrams per serving. It’s worth noting that Legion Pulse offers two varieties: Either with caffeine or without. You can choose your poison at checkout. 

While both pre-workouts combine caffeine and L-theanine in the formula for added mental focus², the Legion Athletics pre-workout offers more transparency in the formulation. Each ingredient is called out by name and dose, unlike the proprietary complexes Nitraflex uses. 

We know the price is over $2 per serving, but our expert product testers ultimately feel more comfortable suggesting brands that provide full transparency on ingredients. 

For the full scoop, check out our Legion Pulse pre-workout review.

Customer Experience 

GAT Sport earns a middle-of-the-road 3-out-of-5-star rating for the overall customer experience. The brand offers full refunds within 30 days if you make a return of an unopened product (minus a 15% restocking fee). If you have opened it and don’t like it for any reason, the brand provides merchandise credit. 

Ordering Nitraflex Pre-Workout

Ordering Nitraflex is as easy as clicking add to cart. Before adding this pre-workout to your cart, you’ll have subscribe options for the ability to save 10% on each order. During the checkout process, you’ll have the ability to pay with a credit card, PayPal, or pay later with Sezzle. 

Plus, if your order from GAT Sport is over $50, the brand offers free shipping. For orders less than $50, you’ll have a $7 flat shipping fee within the contiguous U.S.

You may also like knowing that GAT Sport offers discounts for military, military spouses and dependents, first responders (law enforcement, fire, and EMS officials), government employees (federal, state, and local), teachers (K-12 to University teachers and staff), and students. You will need to visit the GAT Sport’s exclusive discounts webpage to claim these offers. 

Customer Reviews

On the GAT Sport website, Nitraflex Advanced has a 4.8-out-of-5-star rating with over 200 reviews. The majority of customer reviews are positive and boast about taste and caffeine content. Many customers even note they’ve been using Nitraflex Advanced for several years. 

Amazon offers a similar story but features over 7,000 customer reviews and an average rating of 4.6 out of 5 stars. After sifting through Amazon customer reviews, it is noticeable that GAT Sport has changed the formula and some customers prefer the original blend of ingredients. One review was originally posted in 2019 and the writer came back to revise their testament in March of 2021, deeming it a 1-star review because Nitraflex didn’t use to contain DMAA and now it does. 

Final Verdict of Our Nitraflex Pre-Workout Review

The price per serving on the Nitraflex Advanced pre-workout offers an ideal price point to try it out for first-time users. That said, it’s not the best pre-workout for beginners. The high caffeine content is not for the faint of heart. 

• The 325-milligram caffeine dosage may not be suitable for all folks. 
• Nitraflex is best for morning and afternoon workouts and is not to be taken within five hours of bedtime. 
• Ideally our testers would like to see ingredients and doses called out individually. 
• Nitraflex Advanced does not provide any information on third-party testing. 

Full Rating

Nitraflex Pre-Workout

Nitraflex Pre-Workout offers an affordable and powerful pre workout formula. It features 325 mg of caffeine per serving, which is over 3x more caffeine than the average cup of coffee. The website notes not to combine with other caffeine products or take more than one scoop per 24-hour period.

Product Brand: GAT Sport

Product Currency: $

Product Price: 34.99

Product In-Stock: InStock

Editor's Rating:
3.71

Nitraflex Pre-Workout: FAQ

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any diseases.

References

1. Rogers JM, Gills J, Gray M. Acute effects of Nitrosigine® and citrulline malate on vasodilation in young adults. J Int Soc Sports Nutr. 2020 Feb 24;17(1):12. doi: 10.1186/s12970-020-00343-y. PMID: 32093766; PMCID: PMC7041093.
2. Owen GN, Parnell H, De Bruin EA, Rycroft JA. The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutr Neurosci. 2008 Aug;11(4):193-8. doi: 10.1179/147683008X301513. PMID: 18681988.
3. Kerksick CM, Wilborn CD, Roberts MD, et al. ISSN exercise & sports nutrition review update: research & recommendations. J Int Soc Sports Nutr. 2018;15(1).
4. Sabater-Molina M, Larqué E, Torrella F, Zamora S. Dietary fructooligosaccharides and potential benefits on health. J Physiol Biochem. 2009 Sep;65(3):315-28. doi: 10.1007/BF03180584. PMID: 20119826.
5. Jones, R.L., Barnett, C.T., Davidson, J. et al. β-alanine supplementation improves in-vivo fresh and fatigued skeletal muscle relaxation speed. Eur J Appl Physiol 117, 867–879 (2017). https://doi.org/10.1007/s00421-017-3569-1
6. Maté-Muñoz, J.L., Lougedo, J.H., Garnacho-Castaño, M.V. et al. Effects of β-alanine supplementation during a 5-week strength training program: a randomized, controlled study. J Int Soc Sports Nutr 15, 19 (2018). https://doi.org/10.1186/s12970-018-0224-0