The 9 strongest pre-workouts, tested by experts

Why we like Transparent Labs BULK BLACK as strongest overall

Transparent Labs BULK BLACK formula was scientifically crafted to help enhance strength and improve mental focus. As the strongest pre-workout in the Transparent Labs BULK series, it boasts higher dosages of certain ingredients while remaining free of artificial flavors, fillers, and more.

Unlike some pre-workout supplement brands, Transparent Labs provides formula transparency so you know what you’re getting with each scoop. According to the nutrition label, each serving contains 275-325 milligrams of natural caffeine. This is an amount where gym-goers may be able to delay fatigue further and boost exercise performance. (1)

Another form of caffeine, Infinergy™ is also on the ingredient list and provides 75 milligrams in one serving. This trademarked combination of caffeine and malic acid may help extend the stimulatory effects of caffeine without causing jitters or a post-workout energy crash. BULK BLACK is the only pre-workout on this list containing Infinergy™ and contributes to it being considered the strongest overall.

One of our expert product testers attested that he enjoyed the long-lasting, non-crashing effects this pre-workout powder provided. 

The BULK BLACK pre-workout formula also contains clinically-dosed active ingredients, like 2.5 grams of BetaPure betaine anhydrous and 4 grams of beta-alanine. Research suggests that 2.5 grams of betaine anhydrous may improve muscular endurance, thus allowing more reps, which is handy when weightlifting. (2) 

Four to six grams of beta-alanine may reduce lactic acid by elevating the protein building block,  carnosine. (3, 4)  This action delays muscle fatigue and may delay the time to fatigue.

8,000 milligrams of the nitric oxide supporter citrulline malate are also included in each serving. Studies suggest it may improve workout performance by helping to optimize blood flow and nutrient delivery to muscles. (5) Some pre-workout formulas use L-arginine, but overtime researchers determined that it is less effective than citrulline malate at increasing nitric oxide. (6)

Another one of our product testers mentioned how much more focused he was after consumption. Ingredients like L-tyrosine, Alpha-GPC, and L-theanine are said to improve memory, boost motivation, and increase attention. (7, 8, 9)

In addition to BULK BLACK’s science-backed ingredients, we also like that it tastes good and mixes well. There are seven flavors, with options like sour gummy and blue raspberry. One of our product testers liked strawberry kiwi but didn’t like peach mango. They noted that it’s probably because it’s not super sweet like the pre-workout formulas with artificial ingredients.

One container of BULK BLACK includes 30 servings, and each serving costs about $1.83. Compared to other strong pre-workout options, this one is slightly above average. Its high-quality formula, which has been third-party tested for unsafe and banned substances, justifies the price.

To learn more, visit our full Transparent Labs pre-workout review.

What customers are saying

On Amazon, a customer named Mark Y, commented that the higher price of BULK BLACK was justified by its transparent label and third-party testing. He also remarked that it helps him get amped up before a workout.

Another Amazon customer, A. Walker, mentioned that it has a somewhat sour taste but provides him with a good energy boost for morning workouts.

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Why we like Legion Pulse as strongest natural

Legion Pulse is a 100% all-natural pre-workout formula aimed at enhancing mental focus, increasing blood flow, and providing an energy boost. It comes in 20 caffeinated and non-caffeinated flavors. The formula is made in the USA, has been third-party tested for purity, and doesn’t include artificial food dyes. 

The Pulse formula contains evidence-based levels of key ingredients, like L-theanine, citrulline malate, beta-alanine, and caffeine.

The amino acid L-theanine is a nitric oxide booster that may improve muscle blood flow, much like citrulline malate. However, it may also alleviate mental stress and increase attention, even in 200-milligram doses (10, 11).  The 350-milligram caffeinated version of this formula contains 350 milligrams of L-theanine per serving, which are hefty doses. When combined with caffeine, it may further improve mood and memory, which could be beneficial while working out. (12) 

Legion Pulse contains 3.6 grams of beta-alanine and 300 milligrams of alpha-GPC. Gym-goers may notice improved muscle endurance, increased lean mass, and enhanced growth hormone secretion from these ingredients. (3, 13, 14) 

If you’re not used to high-stim pre-workouts, the 350 milligrams of caffeine anhydrous in this formula could be overpowering. Therefore, it may be best to try a single scoop instead of consuming two scoops. Our product tester, a Level 2 Weightlifting Coach, didn’t feel overstimulated by it, though, likely due to the calming effects of L-theanine. He remarked that it was his favorite pre-workout for energy. 

Flavor-wise, two of our product testers said it tasted bitter, but one said the effects still made the pre-workout worth it. The formula also mixed well without requiring much shaking. 

Legion Pulse only provides 20 servings per tub at $44.99, so depending on your workout frequency, you may need two monthly. At $2.25 per serving, it’s definitely on the more expensive end, but it’s considered a high-quality pre-workout.

Check out our complete Legion Pulse pre-workout review for more insights.

What customers are saying

Legion Pulse is a frequently purchased pre-workout on Amazon with over 16,000 ratings. Customers say it’s an absolute game-changer, delivering in taste and performance. 

Another customer, Jacob Wooten, said, “The Blueberry Raspberry tastes awful,” but he went on to say, “I feel a good enough boost in my workouts without it being too intense like some others.”

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Why we like Nutricost Pre-X Xtreme as strongest high stim

Nutricost Pre-X Xtreme takes the cake as the strongest high-stim pre-workout primarily due to its caffeine content (300 milligrams). This high dose of caffeine is known to significantly boost energy levels, enhance alertness, and improve focus, making it an ideal choice for those seeking an intense pre-workout experience. (1)

While Pre-X Xtreme contains several key ingredients commonly found in pre-workouts, many are clinically underdosed. L-citrulline is provided at 4 grams, falling short of the recommended 6-8 grams needed to enhance nitric oxide production and improve blood flow. (15) Beta-alanine is included at 2 grams, well below the 4-6 grams necessary for effective muscle carnosine loading to buffer lactic acid and delay fatigue. (4) And, the 1.5 grams of betaine anhydrous in the formula does not meet the optimal 2.5 grams required for improved strength and power output. (2) 

Additionally, L-tyrosine is dosed at 250 milligrams. Though clinical studies in humans are limited, the suggested dosage for enhancing cognitive function and stress resistance is 100–150 milligrams per kilogram of body weight. That means a person weighing 200 pounds  (90.9 kilograms) would need to take 9-13 grams of L-tyrosine for optimal results. Alpha-GPC (200 milligrams) also falls short of the 300-600 milligrams needed for improved cognitive performance and increased power output. (7, 16) 

Nutricost’s pre-workout complex also includes 2 grams of taurine, which falls within the 1-6 grams per day range used in clinical studies. Taurine may improve time to exhaustion, strength, power, and muscle recovery, though more research is needed. (17)  

Despite the clinically underdosed key ingredients, the combination of caffeine with moderate amounts of these other performance-enhancing compounds can still provide a synergistic effect to improve energy and mental focus during a workout. 

Nutricost makes its supplements in a GMP-compliant facility and participates in third-party testing. This ensures the highest standards of quality, purity, and safety. Pre-X Xtreme is vegetarian-friendly, non-GMO, and gluten-free. However, it does contain artificial flavors and sucralose, which may be a concern for customers who prefer natural ingredients and are looking to avoid artificial sweeteners.

The 30-serving container is priced just under $1.10  per serving, while the 60-serving container costs $0.92 per serving. Both options are well below the average price for a high-stim pre-workout. If you’re looking to save even more, a subscription will bring your price down 20%.

To learn more, see our comprehensive Nutricost Pre-X Xtreme review.

What customers are saying

Amazon customers appreciate the value and high-quality ingredients of Nutricost’s Pre-X Xtreme. However, opinions are mixed on the taste and effectiveness of this supplement. 

Joey C. remarks, “not the best tasting but has good ingredients for the price.”

Nate, another Amazon customer, writes, “I prefer my pre-workout with more chemicals and beta-alanine. Also, the scoop for the pre-workout was a little bigger than I would have liked. I like smaller, more potent doses.”

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Why we like C4 Ultimate Pre Workout Powder as strongest for pump

C4 Ultimate Pre Workout Powder is all about maximizing power at the gym. The stimulating supplement gets the blood pumping  with VELOX®—a patented blend of L-citrulline and L-arginine—and supports muscle endurance with CarnoSyn® Beta-Alanine and BetaPower® betaine anhydrous. 

The patented performance blend, VELOX, provides 3 grams of L-citrulline and 3 grams of L-arginine. Many pre workout formulas contain L-citrulline and L-arginine, but the evidence to support the  claims that combining the two nitric oxide enhancers improves blood flow and endurance is based limited evidence. (5, 34) While L-citrulline at doses of 2.4 to 6 grams seems effective, the benefits of combining are less apparent. (35)

The pre workout formula uses a patented time-released form of beta alanine called CarnoSyn®. Research suggests you need higher doses of non-time released beta-alanine—6 grams daily—to maximize benefits. (4) CarnoSyn has lower amounts of beta-alanine with 3.2 grams per serving, but may effectively support exercise capacity as a time-released formula. (4, 36).  

C4 Ultimate Pre Workout falls a bit short on dosing of betaine anhydrdous with 1.25 grams from the patented BetaPower® formula. It does, however, pack in a heavy dose of caffeine with 300 milligrams per serving for energy. 

Cellucor’s pre workout formula also has TeaCrine® as theacrine and Dynamine™ as methyllberine, both purported energy boosters. A recent study found theacrine ineffective as a pre workout energy booster, while another study found methylberine helped sustain energy and improve concentration and stress tolerance, so potential benefits are mixed. (37, 38) 

C4 Ultimate Pre Workout is the only pre workout with PeptiPump®, a proprietary peptide formula that purportedly increases muscle oxygenantion and blood flow. (39)  However, these claims are based on results from animal studies and may not work exactly the same in humans. (40)

The supplement’s formula also includes nootropics: L-tyrosine, caffeine, and huperzine A. (1, 7, 41) Huperzine A is used in traditional Chinese medicine to improve circulation and is a popular ingredient in pre workout formulas. However, research fails to show that the ingredient enhances cognitive function during workouts. (41)

Cellucor’s pre workout has a lot to offer, but it falls short on dosing and contains ingredients that require more research. Further, it’s difficult to assess safety of C4 Ultimate Pre Workout since it uses proprietary blends and has no third-party testing. 

The pre workout formula is sugar-free, but uses the artificial sweeteners sucralose and acesulfame potassium and has artificial flavors. The pumped up pre workout is also more expensive than the average market price at $2.50 per serving. But, Cellucor offers 30% off the retail price with a subscription.

Check out our full C4 Ultimate Pre Workout review for more information.

What customers are saying

Amazon customers love the energy and pumping power they get from C4 Ultimate Pre Workout, but not everyone enjoys the supplement’s taste. A few reviewers also note a tingling sensation after taking the pre workout.

Verified Amazon customer Paul J.D. writes, “Don’t really like the flavor but still works great.”

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Why we like Gainful Pre-Workout Caffeinated High Intensity + Creatine as strongest with creatine

Gainful Pre-Workout High Intensity + Creatine features a comprehensive blend of ingredients aimed at enhancing both physical performance and mental focus. The inclusion of 5 grams of creatine meets the clinically recommended daily dose, known for improving strength, power, and muscle mass. (20)  

The 330 milligrams of L-theanine, an amino acid found in tea, is a substantial dose known to promote relaxation without drowsiness and can help smooth out the stimulatory effects of caffeine, leading to a less jittery energy boost. The natural caffeine is moderately dosed (200 milligrams) and helps enhance alertness, focus, and overall exercise performance. (12, 1) 

L-citrulline DL-malate, at 4 grams, is slightly below the optimal 6-8 grams per day recommended for maximizing nitric oxide production. Citrulline enhances blood flow and nutrient delivery, which may reduce fatigue and improve endurance. (15) 

The 1.5 grams of beta-alanine is also on the lower side compared to the clinically effective range of 4-6 grams. Beta-alanine helps increase carnosine levels in muscles, which buffers acid buildup and may delay fatigue. (4)

The supplement also contains 2.5 grams of leucine, an essential branched-chain amino acid (BCAA) crucial for muscle protein synthesis and recovery. This dose is within the effective range, as studies suggest around 2-3 grams of leucine per serving can significantly stimulate muscle protein synthesis. Gainful also includes 500 milligrams each of isoleucine and valine, the other two BCAAs. (21)

A 14-serving container of Gainful’s pre-workout costs $26, putting each serving at $1.86. While this is above average for a pre-workout, Gainful contains BCAAs and creatine, so you’re getting three supplements in one.

To learn more, check out our complete guide on the best creatine.

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Why we like Onnit Alpha Brain Pre Workout as strongest for focus

Onnit Alpha Brain includes several key ingredients designed to enhance workout performance and mental clarity. Ashwagandha, for instance, is included at 225 milligrams. The herb is known for its ability to reduce stress and improve mood, potentially impacting focus and a positive mindset during workouts. That said, the dose is on the lower end of the 120-5,000 milligram range most studies recommend. (18)

The formula also contains 200 milligrams of caffeine, which is a moderate dose compared to other high-stim pre-workouts which contain 250-400 milligrams. Beta-alanine, at 2.4 grams per serving, is also a bit below the clinically recommended range of 4-6 grams. Similarly, the 2.4 grams of L-citrulline is less than the ideal clinical range of 6-8 grams.

Additionally, Onnit includes 125 milligrams of Alpha-GPC. The dose of Alpha-GPC is slightly below the 300-600 milligrams often studied for cognitive benefits and enhanced power output, but it still contributes to improved mental focus and cognitive function. (16) Theobromine, found in cacao, is included at 100 milligrams, which is a supportive dose for improving mood and providing a mild, sustained energy boost. (19) 

Together, these ingredients work synergistically to offer a comprehensive boost in both physical and mental performance, making Onnit Alpha Brain a solid choice, despite some dosages being on the lower end of the clinical spectrum. 

At just under $3 per serving, Onnit Alpha Brain is more expensive than comparable high-stim pre-workouts. At this price, we’d prefer to see third-party testing done.

To read more and see additional products, check out our full Alpha Brain review.

What customers are saying

Amazon reviews for Onnit’s Alpha Brain Pre Workout are limited and mixed. Some customers noticed enhanced energy and focus during their workouts, while others were not happy with the taste, price, and performance of this supplement. 

An Amazon customer with the username “Coffeemom78” wrote, “I do not feel more energetic or focused, just sick to my stomach.”

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Why we like Gorilla Mind Gorilla Mode as strongest for strength and power

The Gorilla Mind Gorilla Mode formula is crafted with ingredients that may help enhance muscle strength and overall performance. With over four cups of coffee’s worth of caffeine and clinically dosed levels of common pre-workout ingredients, it’s made to get you focused and pumped. 

A glance at Gorilla Mode’s tub will show you that there are two nutrition labels. If you’re a beginner or have a lower tolerance for high-stim pre-workouts, stick to one-scoop servings, as displayed on the left. However, if you’re an athlete or simply have a higher tolerance to caffeine, the label on the right side will provide the most impact for strength and power.

There are 40 servings per container, but the cost per serving depends on your current fitness level and preference. Those consuming just one scoop will pay approximately $1.50 per serving. However, those with a higher tolerance for high-stim pre-workouts may prefer two scoops, bringing the cost per serving to $3.00. The latter is more expensive but may be worth it to some as it’s third-party tested and packs potent ingredients. 

For instance, the formula’s 10 grams of pure L-citrulline may support  muscle building operations and researchers are keen to understand this potential better. (26) Three grams per day is the minimum effective dose, and 10 grams may be maximum. (27) 

This formula also provides 5 grams of creatine, which studies suggest is a clinically effective dose for boosting muscle creatine levels and, supporting gains in strength and muscle mass in response to training. (20) Although 2 grams of betaine anhydrous is a little below evidence-based dose, some people who exercise may still respond well over time. (2)  

Our product tester, a Level 2 Weightlifting Coach, says he still felt the pump two hours after consumption. He also remarked that he didn’t experience the caffeine-induced energy crash often associated with strong pre-workouts.  

Besides ingredients that promote physical strength, Gorilla Mode’s formula also contains cognitive-enhancing ones. There are 6 grams of nootropics that may help with mood, attention, and focus. (28) The inclusion of L-tyrosine, an amino acid, and alpha-GPC, a cholinergic compound, may also help with stress and memory. (7, 16) Even further, each serving contains some B vitamins. They, too, may affect general mood and brain health. 

Research shows that mental focus could impact muscle growth and endurance, demonstrating that one’s cognitive state may affect one’s fitness goals. (29) 

Regarding taste, our product tester didn’t hate it but wasn’t sold on it either. He tried the bombsicle flavor and said it just had a sweet taste. Besides that, it’s still one of his favorites from the 45+ pre-workouts he’s consumed.

What customers are saying

Gorilla Mode is a sought-after pre-workout on Amazon for those wanting better focus and power. 

Another customer shared their sentiments but wasn’t a fan of some of the flavors. Izzy M. mentioned, “It does the job, and I’m honestly feeling good after one scoop instead of 2. Volcano Burst was SO good, so good. Watermelon was so chemically and had this almost bitter flavor to it.”

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Why we like Beyond Raw LIT as strongest on a budget

Beyond Raw LIT is made with natural and artificial ingredients combined to help you train with energy, clarity, and pumps. The formula comes in 9 flavors, like Jolly Rancher Cherry and Lemonade, and is affordably priced at just $1.33 per serving. 

Despite its reasonable price, the Beyond Raw LIT formula contains a few clinically dosed ingredients. For example, one scoop is packed with 4.5 grams of two nitric oxide enhancers: 1.5 grams of nitrosigine and 3 grams of L-citrulline. Nitrosigine is a trademarked complex of bonded arginine silicate, which has been shown to enhance muscle blood flow and exercise performance when combined with citrulline malate. (30)  

ElevATP, a proprietary combination of ancient peat and apple polyphenols, also supports blood flow and optimized ATP levels. In addition, ATP plays a role in muscle contractions and could lead to muscle growth. (31) Creatine aids muscle hypertrophy as well. Although it’s under-dosed in this formula, as it’s just 1.5 grams, the other blood flow-inducing ingredients may balance it out. (20) 

Also included in evidence-based dosages are 3.2 grams of CarnoSyn beta-alanine and 250 milligrams of caffeine. The amino acid beta-alanine boosts muscle carnosine levels and may put off muscle fatigue so you can get more reps in. (4) The adequate dosage of caffeine anhydrous may then help you stay focused and perked up for more effective training. 

Additionally, NeuroFactor, a patented extract of whole coffee cherries, is a part of the Beyond Raw LIT formula. Research shows that whole coffee cherries elevate the production of the neuroprotein, brain-derived neurotrophic factor (aka BDNF). BDNF is critical for memory and learning. Therefore, an increase in BDNF levels may lead to cognitive improvement. (32, 33) 

When our product tester tried Beyond Raw LIT, he noted that he felt “in the zone” after taking it. He further commented that it didn’t make him feel anxious or crank up his heart rate, as some pre-workouts do before doing interval training sessions. He also recalled enjoying the flavors, particularly Jolly Rancher Blue Raspberry, and how the powder mixed seamlessly. 

What customers are saying

Comments on the r/Preworkoutsupplements subreddit showcase varied opinions about the Beyond Raw LIT product. For instance, one Reddit user, Nearly_Tarzan, said, “Great taste, but it’s way underdosed for what you pay.” 

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