Overview

Transparent Labs Bulk Black is the pinnacle of a clinically dosed pre-workout supplement for stim lovers. If you have experience with our regular Bulk Pre-Workout formula but want some extra "pep" in your step, this is the pre-workout for you. Each scoop of Bulk Black packs over 17 grams of proven nitric oxide boosters, hard-hitting nootropics, natural testosterone-supporting ingredients, and muscle fortifiers dosed according to scientific evidence, so you can bring the noise every time you walk into the gym. Like all Transparent Labs pre-workout formulas, Bulk Black contains absolutely no artificial sweeteners, flavors, food dyes, or added sugars.

Key Features

Evidence-Based "Hardcore" Pre-Workout for Lean Muscle Gain: Like the regular Bulk Pre-Workout formula, Bulk Black features a comprehensive lineup of science-backed active ingredients to help dedicated athletes and gym-goers build muscle mass and perform at peak capacity.
Experience Intense Muscle Pumps with Proven Nitric Oxide Boosters: Bulk Black Pre-Workout contains clinical doses of L-citrulline, beta-alanine, and betaine anhydrous to enhance blood flow and give you those oh-so-satisfying, intense muscle pumps during training.
Stimulates Mental Sharpness, Focus, Drive, and Energy: Get into the "zone" every time you hit the gym with nootropics backed by scientific evidence, like alpha-GPC (AlphaSize®), caffeine (PurCaf®), L-tyrosine, and taurine. Bulk black pre-workout contains just the right amount of hard-hitting nootropics to deliver a psychotropic rush without the dreaded post-workout crash.
Epic All-Natural Flavors Sweetened with Stevia: Many other pre-workout formulas are laden with artificial sweeteners, food dyes, and unnecessary fillers. We know you care about what you put in your body, so Bulk Black Pre-Workout contains absolutely no artificial sweeteners, added sugars, or food dyes, and the formula is naturally sweetened with stevia. Choose from multiple refreshing flavor options, including Black Cherry, Cherry kiwi, Peach Mango, Blue Raspberry, Watermelon Peach, Blueberry Pomegranate, and Sour Gummy.
Third-Party Tested and Certified for Quality: As part of our commitment to industry-leading transparency and quality, every batch of this product is tested by a third-party lab for purity and potency. You can find all of our test results in the footer of our website. This product is also certified by Informed Choice to meet the highest standards for athletes and consumers.

Active Ingredients and Benefits

*Doses listed are per serving (1 full scoop)

L-Citrulline Malate (2:1) | 8,000 mg

L-citrulline is an amino acid naturally found in watermelon that plays an important role in kidney function. It's become a popular ingredient in pre-workout supplements due to its ability to boost nitric oxide levels [1]. When nitric oxide production increases, blood flow improves, allowing nutrients and oxygen to replenish muscle tissue more efficiently. Ultimately, this translates to greater muscle pumps and heightened energy levels.

Numerous studies have demonstrated the ergogenic effects of L-citrulline malate, the citrulline salt of malic acid, such as:

Improving strength, aerobic performance, and muscle endurance [2, 3]
Elevating nitric oxide levels even more than equivalent doses of L-arginine [4]
Enhancing muscle anabolism and reducing muscle catabolism [5]

Beta-Alanine | 4,000 mg

Beta-alanine is a beta-amino acid that combines with L-histidine to form a dipeptide known as carnosine. Supplementing with beta-alanine has been shown to increase muscle carnosine levels, which are quickly depleted during intense exercise [6].

Carnosine is an endogenous dipeptide that functions as a buffer in muscle cells, thereby attenuating the accumulation of acidic byproducts of muscular exertion (e.g. lactate and hydrogen ions) [7]. Hence, bolstering muscle carnosine levels—via beta-alanine—allows you to push yourself longer and harder in the gym.

Pre-workout supplements almost always contain beta-alanine but in inefficacious doses. We made sure to include a full clinical dose of beta-alanine (4,000 mg) in every scoop of BULK Pre-Workout. Relevant evidence-based benefits of beta-alanine include:

Delaying the onset of neuromuscular fatigue during intense exercise [8]
Increasing overall muscle strength [9]
Improving muscle endurance and total work capacity [10]
Reducing and combatting the formation of dysfunctional proteins and promoting the formation of healthy proteins [11]
Significantly increasing lean muscle mass as part of a diligent resistance-training program [12]

*Note that beta-alanine causes a benign tingling sensation known as paresthesia while the body acclimates to higher carnosine levels. This effect is harmless and gradually lessens with consistent use.

BetaPure™ Betaine Anhydrous | 2,500 mg

Betaine, also known as trimethylglycine, is a naturally occurring metabolite that serves as a methyl donor and osmolyte in the body. Though the mechanisms are not entirely understood, betaine supplementation has shown promise in enhancing power output and, to a lesser extent, endurance capacity in athletes [13, 14, 15]. It is plausible that betaine supplementation promotes athletic performance by maintaining cellular hydration and reducing homocysteine levels, thereby encouraging healthy cardiovascular function and blood flow [16].

Taurine | 1,300 mg

Taurine is another staple pre-workout ingredient with diverse benefits for athletes and gym-goers. For one, taurine is a potent nootropic that confers synergy with caffeine to promote focus and reduce brain cell inflammation and oxidative stress [17, 18].

Taurine can also enhance physical performance via increased blood flow to skeletal muscle tissue [19, 20]. Greater blood flow to muscle tissue encourages a favorable milieu for muscle function and recovery during training. Additionally, taurine supplementation has been shown to improve performance in endurance athletes [21].

L-Tyrosine | 1,000 mg

L-tyrosine is a conditionally essential amino acid and precursor to dopamine and norepinephrine, two neurotransmitters that govern motivation and reward. Research shows that supplementing with L-tyrosine can significantly enhance cognitive performance, especially under acutely stressful situations (such as intense training) [22]. L-Tyrosine has also been shown to improve “cognitive flexibility,” meaning it can help you adapt to changing cognitive demands without letting extraneous thoughts take over [23].

AlphaSize® Alpha-GPC | 300 mg

Alpha-GPC (glycerylphosphorylcholine) is a popular nootropic supplement and a bioavailable source of choline, an essential micronutrient for cholinergic transmission and, by extension, cognitive function. Alpha-GPC is primarily found in the brain and is one of the two major storage forms of choline in the cytosol (interior space of cells), along with phosphocholine [24].

This ingredient can enhance physical and mental performance by increasing acetylcholine and growth hormone production [2 5, 26, 27]. The former is important for focus and mental acuity, while the latter promotes fatty acid oxidation and reduces muscle tissue breakdown. As such, alpha-GPC (as patented AlphaSize®) is one of the key ingredients in Bulk Pre-Workout.

PurCaf® Organic Caffeine | 275 mg

While most pre-workouts contain synthetic caffeine anhydrous, we formulated BULK Black Pre-Workout with organic caffeine derived from green coffee beans (as PurCaf®). On the molecular level, caffeine (chemically known as 1,3,7-trimethylxanthine) is an alkaline, organic substance derived from xanthine — a biologically important purine base found in many bodily tissues and fluids. Methylxanthines like caffeine and theobromine stimulate the central nervous system (CNS) and heart to promote wakefulness and motivation.

Numerous studies have shown that taking caffeine before exercise can significantly improve overall performance, largely by reducing the rate of perceived exertion [28]. Caffeine may also enhance endurance and strength by increasing fatty acid oxidation and sparing muscle glycogen [29].

L-Theanine | 200 mg

L-theanine is an isomer of the amino acids L-glutamate and L-glutamine. It was discovered centuries ago as one of the primary amino acids in green tea leaves and is also found in various mushroom species.

L-theanine is highly bioavailable when taken orally and actively traverses the blood-brain barrier to enhance mental acuity and attenuate stress [30, 31]. Its nootropic effects are appropriately described as "alert relaxation," which is to say it promotes a sense of calmness while improving focus. L-theanine can also help take the edge off of stimulants, particularly caffeine. In fact, research shows that pairing L-theanine with caffeine creates a nootropic synergy that bolsters cognitive function and alertness more effectively than taking either nootropic on its own [32].

Theobromine | 100 mg

Theobromine is the primary alkaloid found in cocoa beans and is essentially the “little brother” of caffeine. Its functions in the body are suggested to be complementary to those of caffeine, acting as a phosphodiesterase inhibitor and central nervous system stimulant [33].

Research has also found that theobromine has differential contributions to mood and cognitive function compared to caffeine, providing further insight into the distinct yet synergistic nature of these naturally occurring stimulants [34].

Infinergy™ Di-Caffeine Malate | 75 mg

Infinergy™ is a trademarked form of sustained-release caffeine (as di-caffeine malate) that delivers the same mental and physical performance benefits as normal caffeine but with a longer duration of action. In other words, Infinergy™ helps take you the extra mile when you need it most.

SenActiv® | 50 mg

SenActiv® is a patented adaptogenic herb combination featuring Panax notoginseng and rose hips (Rosa roxburghii). The Panax notoginseng in SenActiv® is highly concentrated in ginsenoside R1, a beneficial constituent that helps accelerate muscle recovery during/after intense exercise. Likewise, the rose hips in this ingredient provide several ginsenoside-like molecules that confer synergistic recovery-enhancing effects with ginsenoside R1 [35]. These phytonutrients are suggested to work by bolstering a cellular "cleaning" process known as autophagy, particularly in skeletal muscle cells [36, 37, 38].

BioPerine® | 5 mg

BioPerine® is a patented black pepper (Piper nigrum) fruit extract standardized for its piperine content. Piperine is a natural alkaloid known for its “bioenhancer” properties, improving the bioavailability of molecules that are typically poorly absorbed or extensively metabolized in the liver [39, 40]. Hence, BioPerine® helps your body better absorb and utilize the other active ingredients in Bulk Black Pre-Workout.

Boron Citrate | 3,000 mcg (3 mg)

Boron is an important trace mineral with numerous roles in the human body. Recent evidence suggests that men who supplement with boron daily have higher levels of testosterone and lower levels of estradiol (estrogen) than those who don’t [41].

Zinc Chelate | 10 mg

Chelated zinc is a bioavailable source of zinc, an essential cofactor for various enzymes. Research suggests zinc is crucial for supporting fertility and sperm cell counts in men [42]. This is largely because zinc aids in natural testosterone production, and males who are zinc deficient are at a higher risk of infertility [43].

Vitamins B6 and B12 | 5 mg and 100 mcg

Vitamins, as a collective group, are essential micronutrients that act as coenzymes (read: "helper molecules") for enzymes throughout the body. Vitamins B6 and B12 are water-soluble vitamins that are particularly important for cognitive function, cardiovascular health, nutrient metabolism, and immunity [44, 45]. As such, you can't go wrong with having these in your pre-workout arsenal.

Sodium and Potassium | 180 mg and 125 mg

Many minerals act as electrolytes in aqueous solutions, meaning they carry an electric charge that influences concentration gradients across cellular membranes and enzyme functions. Sodium and potassium are arguably the most important electrolyte minerals, being well-known to impact hydration status and exercise performance [46].

How to Use

For Beginners

To assess tolerance, mix 1/2 scoop of Bulk Black Pre-Workout with 6 to 8 oz of water and consume 20-30 minutes before exercising, preferably on an empty stomach. If the effects feel subtle, increase to a full scoop before the next workout.

For Experienced Pre-Workout Users

Mix 1 full scoop of Bulk Black Pre-Workout with 10 to 12 oz of water and consume 20-30 minutes before exercising, preferably on an empty stomach.

FAQs

What is the Difference Between Bulk and Bulk Black?

Bulk Black contains a stronger dose of caffeine and theobromine and has added Infinergy™ sustained-release caffeine. The formulas are otherwise the same.

How Much Caffeine is in Bulk Black?

Bulk Black contains approximately 305 mg of caffeine per serving, from organic green coffee beans and di-caffeine malate.

Does Transparent Labs Bulk Black have Creatine?

No, this pre-workout formula does not contain creatine.

How Should Bulk Black Pre Workout be Taken to Maximize its Effectiveness?

In terms of timing, we recommend taking Bulk Black 20-30 minutes prior to your workout. In terms of how much water to drink with Bulk Black, we recommend mixing 8-12 fl. oz of water with 1/2 scoop (to assess tolerance) and mixing 16-24 fl. oz of water with 1 full scoop.

I am Subjected to Drug Testing for my Sport, Can I Take PreSeries Bulk Black Pre-Workout?

Yes, absolutely. Transparent Labs Bulk Black Pre-Workout contains zero banned substances and is Informed Choice certified for athletes.

Why Doesn't Bulk Black Contain Creatine?

Large doses of caffeine may interfere with the ergogenic effects of creatine [47]; since Bulk Black Pre-Workout contains caffeine, we decided to keep the creatine separate.

What is the difference between PreSeries Bulk Black, PreSeries Lean, and PreSeries Stim-Free?

Bulk Black is designed to support lean muscle growth and includes a testosterone support complex, while Lean pre-workout is designed to support fat loss and includes a thyroid support complex. Stim-Free, as the name suggests, contains zero stimulants and has added elevATP. If you want to see how we compare Bulk Black to other well-rated pre-workouts, check out our best pre-workout blog post here.

I Don't Live in the United States, Can I Still Buy PreSeries BULK?

Yes - our fulfillment center allows us to ship worldwide (with some exceptions due to fraudulent activity in certain countries; see here for more info). Standard shipping for international orders typically takes 10-14 business days to arrive.

Does this Product Contain Nuts?

No! While Transparent Labs Bulk Black Pre-Workout is manufactured in a facility that processes nuts (coconuts and peanuts), our allergen control program requires sanitizing and cleaning of the manufacturing equipment to avoid cross-contamination of allergenic and hypoallergenic materials.

Muscle-Building Bundle

Grass-Fed Whey Protein Isolate

BCAA Glutamine

Creatine HMB

Bulk Black Pre-Workout

Growth

Grass-Fed Protein+ Bars