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Most weightlifters and bodybuilders will use mass gainers or protein powders to help build muscle, but could the secret to putting on high-quality size lie in a pre-workout? That’s the promise behind Transparent Labs’ BULK pre-workout, which, as its name suggests, is formulated to help those looking to bulk. 

As a certified personal trainer and nutrition coach, I was a bit skeptical heading into this Transparent Labs BULK review on whether this would actually deliver on its promise. That’s why I tried it for a month and dug deep into its ingredients list to see if it has something to offer that other pre-workouts don’t, and whether you should spend your hard-earned money on it. 

Our Transparent Labs BULK pre-workout review has all the answers you’re looking for. 

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.

A Heaping Scoop of Pre-Workout Reviews by Actual Gym-Goers  

The Garage Gym Reviews team consists of certified personal trainers and competitive weightlifters who run the pre-workout spectrum—some of us need it just to get under the bar, and others just need a little boost to get the blood flowing. Our diverse training background and caffeine tolerances allow us to recommend the best pre-workout for just about anyone, regardless of their training goals. 

Transparent Labs BULK

Transparent Labs BULK Pre-Workout

GGR Score: 4.6 starstarstarstarstar

Product Highlights

  • Formulated to help support muscle gain 
  • 20 grams of research-based active ingredients per serving 
  • 8 flavor variations are available

Pros & Cons


  • Transparent ingredient list
  • No artificial sweetener or color
  • Moderate dose of caffeine
  • 8 flavor options
  • 60-day money-back assurance


  • No creatine
  • Some users report it tastes bad

Bottom Line

Transparent Labs’ BULK supplement is attractive to those whose primary focus is split between potential muscle gain and a pre-workout pump. While the taste is questionable, the product works well for most users.

A Quick Look at the Transparent Labs BULK

Transparent Labs BULK is a pre-workout supplement designed to help people who are looking to build muscle and gain strength. It contains a number of ingredients shown to help boost muscle endurance, focus, and energy, all of which are present in research-backed doses. 

Unlike many pre-workouts that contain a high dose of caffeine, Transparent Labs BULK only has 180 milligrams, which is the same as two cups of coffee, and 30 milligrams of DiCaffeine Malate, a form of caffeine that’s released into the bloodstream slower than regular caffeine and tends to last longer (we’ll dive into it more in a later section). 

transparent labs bulk reaching into bottle

We’re a little surprised to see no creatine in a pre-workout designed to help with muscle gains, especially since just about every study done on the supplement has linked it with improved muscle mass and strength, according to the International Society of Sports Nutrition.1 

That said, there are some vitamins and minerals that can help support testosterone production and muscle protein synthesis.

Before You Buy

Is Transparent Labs BULK Worth It?

Transparent Labs BULK is worth it if you’re looking for a pre-workout that contains a high-quality list of ingredients with research-backed doses to help support increased muscular endurance and pumps in the gym. Another bonus is that it’s a moderately-priced pre-workout (there are more budget-friendly options, but it’s far from being the most expensive).  

It should be noted that the name is nothing but a marketing technique, and that it won’t be the magic key to your bulking journey or instantly help you put on muscle—that comes from consistent work in the weight room. 

Here are a few people who we think will enjoy Transparent Labs BULK, and who might want to look for another pre-workout. 

Related: Best pre-workout for men 

Great for:

  • Gym-goers who don’t like taking a lot of caffeine 
  • Anyone who’s trying to build muscle 
  • Those who prefer supplements without any artificial ingredients

Not recommended for:

  • People with a high caffeine tolerance 
  • Those who want creatine in their pre-workout 
  • Anyone on a tight budget

Transparent Labs BULK Specs

Price per serving$1.66
Flavors Strawberry Kiwi, Piña Colada, Blue Raspberry, Watermelon, Black Cherry, Sour Grape, Green Apple, Orange, Strawberry Lemonade, Lemon Lime, Peach Mango 
Key ingredientsCitrulline Malate, Beta-Alanine, Branched-Chain Amino Acids (BCAAs), Taurine, Betaine Anhydrous (BetaPure), L-Tyrosine, L-Theanine, Alpha GPC, Caffeine Anhydrous, Theobromine, Infinergy (DiCaffeine Malate), AstraGin, Boron, Vitamin D 
Third-party tested?Yes
BenefitsEnergy, Muscular Endurance, Pumps, Muscle Growth
Serving Size1 scoop (22.9 g) 

Experience Using Transparent Labs BULK

The first thing I noticed about Transparent Labs BULK is that it has a larger scoop compared to many of the other pre-workouts I’ve taken over the past few years. Here’s a picture of the scoop compared to a few other pre-workouts in my collection (Transparent Labs is the clear one). 

Pre-workouts aren’t like multivitamins when it comes to swallowability, but the large scoop is worth mentioning because it means you’re getting more ingredients, and luckily Transparent Labs has made sure not to sacrifice quality for quantity’s sake. 

transparent labs bulk scoop

Despite the lower caffeine content, I felt energized and focused after taking Transparent Labs BULK. Caffeine tolerance is a very subjective matter, but I’d imagine that most people who like to lift before the sun rises might want something a little stronger than this. I tried taking it during one such workout, and while I felt a little more lively, I was still feeling a bit groggy during my session. 

The pumps were also very noticeable when taking this pre-workout, which I think is what most people looking into this pre-workout are curious about. Was I suddenly feeling or looking like Dwayne “The Rock” Johnson after taking it for a month? No, and I don’t think you will either. 


Here, we’ll dive a little deeper into some of the Transparent Labs BULK pre-workout ingredients and let you know what the scientific literature says about them and how they can support your training goals. 


Caffeine is a staple in most pre-workouts, with the exception of stim-free pre-workouts, mostly because it provides energy, but there are other reasons why strength training athletes may want to get some jitter juice in their system before lifting.

A December 2020 review2 on caffeine’s strength training benefits found it lowered people’s rate of perceived exertion (or how hard you feel your body is working to complete a lift) and supported increased muscle power.   

DiCaffeine Malate 

DiCaffeine Malate is a buffered type of caffeine that’s made of two compounds, and you can probably guess what one of them is: caffeine and malic acid. It’s created by bonding two caffeine molecules to one malic acid (malate) molecule, which results in a version of caffeine that has a slower release time than regular caffeine. 

There aren’t many studies on DiCaffeine Malate, and the few that do examine the substance look at it when combined with other ingredients, but an undergraduate student from the College of William & Mary who did his thesis on pre-workouts3 noted it “may serve as a more potent form of caffeine that can increase focus, energy, metabolism, and decreased perception of fatigue.”

Citrulline Malate 

Citrulline Malate is a nitric oxide booster that supports improved muscular endurance and blood flow to the muscles, the latter of which is vital if you’re looking for a pump (when your muscles look temporarily engorged after intense bouts of resistance training exercise). These claims were backed up in an August 2021 review4 of the compound’s benefits. 

Transparent Labs BULK has 6 grams of citrulline malate, and though the optimal dose for physical performance is 8 grams4 there have been studies, such as this small one conducted in July 20195, that found benefits with lower dosages. 


Beta-alanine is a non-essential amino acid (meaning our body makes enough of it and it’s not needed through the diet) that’s been linked with decreased muscle soreness and improved athletic performance, according to an October 2016 meta-analysis6.

The 4 grams of beta-alanine in Transparent Labs BULK is in line with the 4-6 gram dose recommended by the International Society of Sports Nutrition.7

If you’ve never taken beta-alanine before, be aware that it can cause a slight itching or tingling sensation in the face known as paresthesia. This will pass, but if you’re not used to it you might be taken off guard. 

Beta-alanine also helps the body create carnosine, which has heart and brain health benefits. 


A November 2012 review8 said taurine, “Plays an important role as a basic factor for maintaining cellular integrity in the heart, muscle, retina, and throughout the [central nervous system],” and could act as a neurotransmitter (chemical messengers that control bodily functions).

The International Society of Sports Nutrition9 found 1-3 grams of taurine to be the optimal dose for sports training benefits, and Transparent Labs BULK has 1.3 grams per scoop. 

B Vitamins

Transparent Labs BULK isn’t the only pre-workout to load up their pre-workout with Vitamin B12 and Vitamin B6, but by scanning my pre-workout cabinet I can see that it has more than most. This is done because, according to a January 2016 review10, B vitamins are “absolutely essential for every aspect of brain function.”

You get 270% of your daily value (DV) of Vitamin B6 and 4,170% of the DV for Vitamin B12. 

Alpha GPC

Alpha GPC is a natural compound found in the brain that, according to the International Society of Sports Nutrition11, can have a nootropic-like effect on the brain to support increased mental alertness. 

Vitamin D3

A December 2010 review12 found Vitamin D supplementation could help with testosterone support, and Transparent Labs BULK gives you 380% of your DV of this nutrient.  

How Much Caffeine Should I Take Before My Workouts?

Most studies agree that 2-9 milligrams of caffeine per kilogram of body weight is the ideal dose for strength training athletes2, so the 180 milligrams in Transparent Labs BULK is perfect for those 200 pounds or lower. You might need more or less, depending on your size or caffeine tolerance. 

Price Per Serving

Transparent Labs BULK comes in at $1.66 per serving, which isn’t the most budget-friendly pre-workout, but we’ve seen supplements that cost around $2 per scoop, so this falls somewhere in the middle. 

transparent labs bulk scoop into bottle

Taste and Solubility 

Transparent Labs BULK comes in the following flavors: 

  • Strawberry Kiwi
  • Piña Colada
  • Blue Raspberry
  • Watermelon
  • Black Cherry
  • Sour Grape
  • Green Apple
  • Orange
  • Strawberry Lemonade
  • Lemon Lime
  • Peach Mango 

I went with Blue Raspberry, and if you’ve ever had anything blue raspberry flavored then you know how this tastes. I do have to say it doesn’t taste as artificial as other blue raspberry-flavored products, but that might be because Transparent Labs doesn’t use artificial sweeteners, dyes, or preservatives. 

It mixes easily when shaken with water. 

Third-Party Testing 

Transparent Labs’ website shows lab analyses of its products to show they’ve been tested for heavy metals, banned substances, and more.  

Transparent Labs BULK vs Transparent Labs LEAN


Transparent Labs LEAN Pre-Workout

Product Highlights

  • Formulated for those looking to lose weight but maintain muscle mass
  • 14 grams of evidence-based ingredients
  • Naturally flavored and sweetened with Stevia
  • Available in 9 different flavors
  • Backed by a 60-day money-back guarantee

Pros & Cons


  • Includes vitamins/micronutrients to support thyroid production
  • High levels of citrulline to increase oxygen delivery to muscles
  • No artificial sweeteners
  • No artificial colors
  • 60-day money-back guarantee


  • Bitter and unpleasant taste for some consumers
  • Several reports of receiving wrong item

Bottom Line

Transparent Labs’ LEAN pre-workout supplement promises to deliver better endurance, power, alertness, and focus. The fat loss component is less of a guarantee with few reports of an actual change in body composition.

The main difference between Transparent Labs BULK and Transparent Labs LEAN is that the latter contains fewer ingredients than BULK, with the notable exclusions being compounds that are meant to help with muscle building and growth (which makes sense). Both contain the same amount of caffeine and citrulline malate and cost the same, so it’s up to you to determine which is best for your training goals. 

Transparent Labs BULKTransparent Labs LEAN
Price per serving $1.66$1.66
Active ingredients Citrulline Malate, Beta-Alanine, Taurine, Caffeine, DiCaffeine MalateCitrulline Malate, Beta-Alanine, Taurine, Caffeine, 
Flavors Strawberry Kiwi, Piña Colada, Blue Raspberry, Watermelon, Black Cherry, Sour Grape, Green apple, Orange, Strawberry Lemonade, Lemon Lime, Peach Mango Strawberry Kiwi, Piña Colada, Blue Raspberry, Watermelon, Black Cherry, Sour Grape, Green apple, Orange, Strawberry Lemonade, Lemon Lime, Peach Mango 
Third-party tested?YesYes

Transparent Labs BULK vs Cellucor C4

Cellucor C4

Cellucor C4 Pre-Workout

GGR Score: 3.9 starstarstarstarstar

Product Highlights

  • Powerful ingredients
  • Gives a solid boost of energy
  • Dissolves well
  • Affordable price per serving

Pros & Cons


  • Powerful ingredients
  • Gives a solid boost of energy
  • Can aid in training performance
  • Dissolves well
  • Affordable price per serving


  • Some users report unpleasant aftertaste
  • Gives some people headaches
  • Some experience tingling in the face

Bottom Line

If you’re looking for an affordable pre-workout drink from a big-name supplement company, give C4 a look.

Cellucor C4 is a great beginner’s pre-workout and is also much more affordable than Transparent Labs BULK—C4 comes out to 99 cents per scoop. One of C4’s downsides is that its ingredients are often underdosed and may not have as many benefits as BULK, but if you’re new to pre-workouts it’s a great place to start. 

Transparent Labs BULKCellucor C4
Price per serving $1.66$0.99
Active ingredients Citrulline Malate, Beta-Alanine, Taurine, Caffeine, DiCaffeine MalateCaffeine, CarnoSyn Beta-Alanine, Creatine Nitrate, Citrulline Malate, Vitamin C
Flavors Strawberry Kiwi, Piña Colada, Blue Raspberry, Watermelon, Black Cherry, Sour Grape, Green apple, Orange, Strawberry Lemonade, Lemon Lime, Peach Mango Cherry Limeade, Strawberry Watermelon, Grape, Watermelon, Frozen Bombsicle, Icy Blue Razz, Fruit Punch 
Third-party tested?YesNo

Read our C4 pre-workout review for more information. 

Returns, Shipping, And Subscriptions

You can return any unopened Transparent Labs product for a full refund, or if you’ve opened it you can ask customer service for store credit or an exchange. 

Shipping costs vary by location. Transparent Labs offers free shipping on all orders above $149. 

Placing your pre-workout on a subscription can save you 10% off each pre-workout, and ensures you’ll never run out.

Customer Reviews

Transparent Labs BULK has a 4.7 average rating with more than 4,000 reviews as of this writing. 

Final Verdict of Our Transparent Labs BULK Review

While the name is a bit gimmicky, there’s no denying that Transparent Labs BULK is an effective pre-workout for anyone who’s looking to get more focused in the gym and increase their overall size. To be clear, you still need to go into the weight room and lift a bunch of heavy iron, but the research-backed ingredients and doses in this pre-workout are certainly a way to help make that happen more consistently. 

Transparent Labs BULK Rating

Transparent Labs BULK Review

Our Transparent Labs BULK review will let you know if this is the pre-workout for your training goals.

Product Brand: Transparent Labs

Product Currency: USD

Product Price: 50

Product In-Stock: InStock

Editor's Rating:

Transparent Labs BULK

Price Per Serving – 4
Formulation – 5
Taste – 4
Solubility – 5
Side Effects – 4
Third-Party Testing – 5
Customer Service – 5
Customer Reviews – 4.7
Buy Now

Transparent Labs BULK FAQs

Does transparent labs bulk have testosterone?

No, Transparent Labs BULK does not contain testosterone but there are some ingredients that have been linked to increased testosterone levels.

What is the difference between LEAN and BULK transparent labs?

Transparent Labs LEAN is formulated to help support weight loss, while Transparent Labs BULK is formulated to support muscle growth.

Where is transparent labs manufactured?

Transparent Labs is manufactured in Utah, USA. 

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.


  1. Kreider RB, Kalman DS, Antonio J, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. 2017;14:18. Published 2017 Jun 13. doi:10.1186/s12970-017-0173-z
  1. Martins GL, Guilherme JPLF, Ferreira LHB, de Souza-Junior TP, Lancha AH Jr. Caffeine and Exercise Performance: Possible Directions for Definitive Findings. Front Sports Act Living. 2020;2:574854. Published 2020 Dec 11. doi:10.3389/fspor.2020.574854
  1. Canakis, Justin. [2017] The Efficacy and Safety of Six-Weeks of Pre-Workout Supplementation in Resistance Trained Rats. [Undergraduate thesis, College of William & Mary]. 
  1. Gough LA, Sparks SA, McNaughton LR, et al. A critical review of citrulline malate supplementation and exercise performance. Eur J Appl Physiol. 2021;121(12):3283-3295. doi:10.1007/s00421-021-04774-6
  1. Casonatto J, Enokida DM, Grandolfi K. Inter-Individual Responses to Citrulline Malate Oral Supplementation on Post-Exercise Hypotension in Hypertensives: A 24-Hour Analysis. Arq Bras Cardiol. 2019;113(2):218-228. Published 2019 Jul 10. doi:10.5935/abc.20190115
  1. Saunders B, Elliott-Sale K, Artioli GG, et al. β-alanine supplementation to improve exercise capacity and performance: a systematic review and meta-analysis. Br J Sports Med. 2017;51(8):658-669. doi:10.1136/bjsports-2016-096396
  1. Trexler ET, Smith-Ryan AE, Stout JR, et al. International society of sports nutrition position stand: Beta-Alanine. J Int Soc Sports Nutr. 2015;12:30. Published 2015 Jul 15. doi:10.1186/s12970-015-0090-y
  1. Ripps H, Shen W. Review: taurine: a “very essential” amino acid. Mol Vis. 2012;18:2673-2686.
  1. Kurtz JA, VanDusseldorp TA, Doyle JA, Otis JS. Taurine in sports and exercise. J Int Soc Sports Nutr. 2021;18(1):39. Published 2021 May 26. doi:10.1186/s12970-021-00438-0
  1. Kennedy DO. B Vitamins and the Brain: Mechanisms, Dose and Efficacy–A Review. Nutrients. 2016;8(2):68. Published 2016 Jan 27. doi:10.3390/nu8020068
  1. Parker AG, Byars A, Purpura M, Jäger R. The effects of alpha-glycerylphosphorylcholine, caffeine or placebo on markers of mood, cognitive function, power, speed, and agility. J Int Soc Sports Nutr. 2015;12(Suppl 1):P41. Published 2015 Sep 21. doi:10.1186/1550-2783-12-S1-P41
  2. Pilz S, Frisch S, Koertke H, et al. Effect of vitamin D supplementation on testosterone levels in men. Horm Metab Res. 2011;43(3):223-225. doi:10.1055/s-0030-1269854

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