I used Transparent Labs BULK pre-workout for two weeks. Here’s my honest review. 

If you’re looking for a third-party tested pre-workout that delivers on caffeine and L-citrulline, BULK is a great choice. 

Transparent Labs is one of the few supplement companies that takes purity, third-party testing, and, unsurprisingly, the “transparency” of its ingredients seriously. 

However, the flavors aren’t great, and it has a few ingredients that simply don’t need to be in a pre-workout. Nothing sinister — just unnecessary.

All in all, Transparent Labs BULK is my go-to pre-workout, and I recommend it to a lot of my friends. Read this full review to find out if it’s the right one for you.

Best For:

When you want a pre-workout that delivers the pump.

Transparent Labs BULK has plenty of L-citrulline for a good pump. You’ll also get a decent dose of betaine anhydrous, but keep in mind the science on it isn’t strong.

When you prioritize transparent (see what I did there?) ingredients. 

BULK contains no proprietary blends and is third-party tested, so you know exactly what you’re getting. It’s also free of artificial sweeteners and colors.

When you need a solid energy boost without the crash. 

The caffeine gives you energy and focus to power you through training without causing jitters or a post-workout crash.

Not For:

If you live and die by the flavor profile.

The flavors of Transparent Labs BULK are barely average. Taste is subjective, but you’ve been warned.

If you want a pre-workout with zero fillers. 

Transparent Labs BULK also contains some vitamins and minerals, such as boron, zinc, B6, and B12, that are simply unnecessary in a pre-workout.

If you’re sensitive to caffeine. 

While the caffeine in Transparent Labs BULK is just right for most experienced lifters, it’s likely too much if you’re sensitive to caffeine or if you’re just starting out with pre-workouts.

Transparent Labs BULK Ingredients

[image showing the ingredient label]

With third-party testing and zero proprietary blends, Transparent Labs BULK delivers on all the key ingredients. But I’d be happier without all the minerals and vitamins in it.

Also, all the manufacturers that Transparent Labs uses are GMP (Good Manufacturing Practice) compliant, which ensures each batch is high quality. And just to make sure Transparent Labs lives up to its name, you can view every product and its certificate of analysis. 

All in all, Transparent Labs spends a lot of money and time making sure you can trust what’s in its products.

In the interest of full disclosure, I reached out to Transparent Labs for more clarity on all its trademarked ingredients. I was pleasantly surprised by how accommodating and thorough the response was — something that you don’t always get from a supplement company.

Citrulline Malate 2:1

8,000 mg

Mix together L-citrulline and malic acid, and you’ll end up with citrulline malate. There’s 5,300 mg of L-citrulline and 2,700 mg of malic acid in here that might give you a better muscle pump and help you squeeze out another rep or two in your set. 

Citrulline malate itself won’t make you stronger, but it can help you train a tad harder, which in turn makes you stronger. It can also reduce soreness post-workout, so you don’t have to walk like a cowboy for the next week.^[1]

4,000 mg is the minimum effective dose of L-citrulline, so Transparent Labs BULK has got you covered. 

All in all, 5,300 mg is pretty good, but I prefer at least 6,000 mg just to be sure.

Beta-Alanine

4,000 mg

When most people think of pre-workouts, they think of the tingles, aka paresthesia, thanks to beta-alanine. The tingles themselves tell you nothing about the effectiveness of beta-alanine. Rather, it’s a sign of an acute high dose.^[2]

Beta-alanine has been proven to improve muscular endurance in one-to-four-minute high-intensity training (HIIT). But you don’t get those benefits until you reach the saturation point of 179,000 mg. In other words, you’d have to take 4,000 mg of beta-alanine every day for 45 days. 

Betaine Anhydrous (BetaPure™)

2,500 mg

BetaPure is a patented version of betaine anhydrous from non-GMO sugar beets. It’s a popular ingredient in pre-workouts used for improving intracellular hydration, which can lead to a better pump.^[3] Although the science isn’t conclusive.

The marketing of betaine anhydrous often hypes up its effect on muscle endurance and power, but the science on that is way too mixed.

The 2,500 mg of betaine anhydrous in BULK meets the minimum effective dose.

Taurine

1,300 mg

Taurine supplementation may improve training performance and recovery, but the evidence is mixed.^[4] The dosage in these studies varies between 1 gram and 6 grams, so it’s hard to say if the 1,300 mg in Transparent Labs BULK actually does anything for you. 

Here’s my take: If you have an exceptional training session after taking Transparent Labs BULK, I am 99.99% sure those improvements had nothing to do with taurine.

L-Tyrosine

1,000 mg

L-tyrosine is an amino acid the body processes to make chemicals such as dopamine and norepinephrine. These are important for alertness, focus, and attention. L-tyrosine can also reduce blood pressure and improve your cognitive skills in stressful situations.^[5] 

Most of these effects require 100–150 mg of L-tyrosine per kilogram (45–68 mg/lb) of body weight. That said, lifters often report a difference with doses between 200 mg and 500 mg per kilo. That’s as bro-science as it gets, but that doesn’t mean it can’t work. 

If you want hard science that proves 1,000 mg of Transparent Labs BULK is enough to improve your training, there is none.

AlphaSize® 

300 mg

AlphaSize is 50%–52% alpha-glycerylphosphorylcholine (alpha-GPC), 47%–49.5% mannitol (natural sugar alcohol), and 0.5%–1% silicon dioxide. 

Alpha-GPC has two molecules: choline as the main ingredient and glycerophosphate as the substance that helps transport choline to the brain.

Compared to non-branded choline, this patented version is more shelf-stable, has received GRAS status (Food and Drug Administration designation that a chemical or substance is considered safe), and is hypoallergenic.

Choline supplementation might have limited effects on memory and physical performance in healthy young adults and trained athletes (especially if your diet doesn’t fulfill the minimum daily requirements), but the evidence of any effect on performance isn’t consistent.^[6]

Also, to learn more about the ingredients in AlphaSize, you have to email Chemi Nutra, the manufacturer. Why isn’t that information public?

PurCaf® Organic Caffeine 

200 mg

The 200 mg of caffeine (about two cups of brewed coffee) in BULK is likely to be enough to boost your focus and energy.^[7] 

Just for context, 200 mg of caffeine is half of the recommended daily limit for most people.

As a side note, PurCaf is 95% caffeine. The other 5% is minor green coffee bean constituents (such as polyphenols), moisture (water), and macronutrients (e.g., carbs, fiber, and protein from coffee beans).

L-Theanine

200 mg

L-theanine is a naturally occurring amino acid, and supplementing it might improve your cognitive function and offset the elevated blood pressure and jitters that often come with caffeine.^[8]

At 200 mg of L-theanine, Transparent Labs BULK hits the minimum effective dose.

Theobromine

50 mg

Theobromine is caffeine’s more chilled cousin. In addition to improving focus and energy, it can help offset caffeine crashes. 

One study comparing theobromine and caffeine concluded that caffeine affects the nervous system and that theobromine may act mostly by improving blood flow and making the heart pump more efficiently.^[9] 

At 50 mg, Transparent Labs BULK hits the minimum effective dose of theobromine.^[10] But that doesn’t guarantee it will do anything for you.

Senactiv® (Panax notoginseng, Rosa roxburghii)

50 mg

Senactiv is a branded supplement composed of Panax notoginseng and Rosa roxburghii extracts.

A study of notoginseng, funded by Senactiv’s parent company, NuLiv Wellness, showed improved performance and recovery in healthy, untrained men.^[11] 

This might well be the case, but no matter how objective the study claims to be, I remain a skeptic until I see non-funded studies. 

Rosa roxburghii is a promising supplement to improve performance and recovery due to its antioxidant, immune-boosting, and protective effects.^[12] 

But, as with notoginseng, more studies could make these claims rock solid.

Sodium (as Himalayan Rock Salt)

180 mg

Intense sweating during training can lead to a loss of sodium, messing up your body’s delicate electrolyte balance. This imbalance can negatively affect muscle contraction strength, which isn’t great news when lifting weights. 

Having sodium in your pre-workout can help maintain proper electrolyte balance. But it only really becomes an issue when you’re training in hot and humid conditions or doing some mad Rocky Balboa training montage.

Potassium

125 mg

Having potassium in your pre-workout can make a difference in your training if you’re sweating like Hannibal Lecter at the gates of heaven. But if you’re training with air conditioning blasting on full tilt, I wouldn’t worry too much about this. 

Just for context, the recommended daily intake for potassium for adults is around 2,600 to 3,400 milligrams per day for women and 3,400 to 4,700 milligrams per day for men.

Boron

3,000 mcg

Supplementing boron can reduce inflammatory markers, as well as improve bone health, growth, development, and immune response. But there’s no set standard for optimal dosage, making supplementing it a bit of a crapshoot.^[13] 

I honestly don’t see a good enough reason for this ingredient to be in your pre-workout.

Zinc

10 mg

Zinc has all kinds of functions in your body. But supplementing it is only necessary if your levels are inadequate. In which case, you’re better off talking to your doctor about zinc supplementation rather than taking an arbitrary dose in your pre-workout.^[14] 

If you can’t tell yet, I really don’t like seeing these random minerals in pre-workouts.

Vitamin B6

5 mg

As with zinc, the B6 supplementation only makes sense if you’re deficient in it.^[15] I can’t see the point of having B6 in your pre-workout.

Bioperine® (Black Pepper Extract)

5 mg

Bioperine is a branded form of piperine. This ingredient doesn’t do much on its own, but it can increase the absorption of other supplements. 

The piperine in Transparent Labs BULK is there to (at least theoretically) increase the absorption of beta-alanine, L-tyrosine, theobromine, and caffeine.^[16] 

However, the data on all this is weaker than OJ’s glove defense. I am not convinced 5 mg of piperine does much here. But then again, it’s only pepper, so it doesn’t hurt to have it in, just in case.

Vitamin B12

100 mcg

Supplementing B12 is crucial for folks deficient in it — usually older people and hardcore vegans. But I’d rather you talk to your doctor about B12 supplements than take a random dose in your pre-workout.

As with B6 and zinc, why does this need to be here? Here’s your answer: It doesn’t.

My Experience Using Transparent Labs BULK 

I used Transparent Labs BULK for two weeks. Usually, I don’t tell the company I am about to review their product, but I made an exception here. The Strawberry Lemon was so awful that I reached out to Transparent Labs, saying I was reviewing their pre-workout, and asked if they could ship me the Blue Raspberry to try as well — which they did. 

The energy was quite good.

The caffeine gave me a solid boost in focus and energy without being overpowering. I had no crash with this one.

The pump was good too.

Now, it wasn’t the best pump I’ve ever had, but it still gave me what I needed to make the most out of my training.

The two flavors were a mixed bag.

Let’s just say Transparent Labs isn’t going to win any flavor awards any time soon. As mentioned above, I couldn’t stand the Strawberry Lemonade.

The Blue Raspberry though? Still not great, but it’s growing on me, and I’m giving it a 7/10. 

Price

[image of the serving size]

Transparent Labs BULK is very reasonably priced at $1.66 ($1.49 if you subscribe). The industry average is $1.50 so there obviously are some cheaper options. But I can’t think of a single one that is third-party tested and as well dosed on all the key ingredients.

The shipping is $7.99. Subscriptions and orders over $100 have free shipping.

Third-Party Tested and GMP Certified

[screenshots of third-party test results]

Good news! Transparent Labs BULK is third-party lab-tested for purity and potency, and GMP certified for safety and quality. Transparent Labs also lists certificates of compositions provided by a third-party company for all its products.

If you’re looking for purity testing on every batch of its products, you can access the certificate of analysis on the website.

Energy

BULK gave me solid focus and energy that lasted throughout the training session. 

That 200 mg of caffeine was just enough to power me through the training without having to deal with a crash after. 

I’d love to try Transparent Labs BULK with 50 mg more caffeine, but it’s not a deal breaker for me.

I had medium tingles each time, but it was mostly gone after a few hours. A lot of that probably has to do with my high tolerance to beta-alanine after testing 20+ pre-workouts.

Pump

The pump was good, if not great. Still, I didn’t feel like I was lagging in my training because of it. Adding another 700 mg or so of L-citrulline would likely make this even better. 

Taste

[screenshot of flavors from the website]

Transparent Labs BULK comes in 13 flavors:

• Strawberry Lemonade
• Strawberry Kiwi
• Piña Colada
• Blue Raspberry
• Black Cherry
• Peach Mango
• Sour Grape
• Watermelon
• Watermelon Peach
• Cherry Splash
• Orange
• Blueberry Pomegranate
• Tropical Punch

In the online reviews of Transparent Labs BULK, complaints about the taste come up often. For good reason. 

I can honestly say that the Strawberry Lemonade flavor was the worst-tasting pre-workout I’ve ever tried. Adding more water improved it a bit, but not enough to make it taste even remotely pleasant.

The Blue Raspberry was a bit better. But still pretty average. My friend rated the flavors a bit higher than me, but it’s not like he was raving about them, either. But there’s a silver lining here.

Pre-workouts with higher doses of the key ingredients often have an average flavor simply because it’s harder to mask the taste of the ingredients. 

That’s especially true with Transparent Labs BULK, since it doesn’t use any artificial sweeteners or colors. And the older I get, the more I care about the purity of the product and less about the flavor.

So, with this product, the shitty flavors are not that big of a deal since the rest of the product is solid.

Mixability

[image of the pre-workout mixed up]

I’ve got no complaints about mixability. Transparent Labs BULK is easy to mix, and there’s no grittiness, lumps, or anything else you’d have to chew through. It doesn’t get stuck in your shaker, either.

Customer Experience

The whole ordering process and delivery were great. The website is easy to use, and I wasn’t bombarded with bullshit marketing emails after ordering. The delivery was quick too. 

Transparent Labs BULK Alternative

Outwork Nutrition’s Pre-Workout

If you’re after a pre-workout with zero filler ingredients, Outwork is a great option. It has 100 mg more caffeine than Transparent Labs BULK but about 300 mg less L-citrulline. It’s also $0.50 more expensive per serving. 

You can read my full review of Outwork Nutrition’s pre-workout here. 

And if you want to read through all my previous pre-workout reviews, you can do so here. 

How I Tested Transparent Labs BULK

I test each supplement across eight categories, pouring over studies and combining them with personal feedback.

When I conduct tests and write my pre-workout reviews, my commitment is to the truth, even if it ruffles a few feathers. There are no hidden agendas, no fluff — just rigorous research.

1. Ingredients

I care mostly about two ingredients in pre-workout supplements: caffeine and L-citrulline. Then there are two that might be worth your dollars: beta-alanine and electrolytes. But those two are far from mandatory.

Once I know a pre-workout has the two ingredients I care about, I check that the dosage of both ingredients is where it should be to provide the stimulation I need. 

Besides those two, most other ingredients serve a different purpose: marketing. The fewer ingredients I see on the label, the better. 

You can read more about the ingredients I look for on my how I test ingredients page. 

2. Price per serving

I care whether a single serving will give me enough of the two ingredients above for the needed stimulus. Ultimately, I want the best bang for the buck per serving. 

Often, the key ingredients are about the same in most pre-workout supplements. It’s the proprietary blends and trademarked ingredients that raise the price. Both of which rarely contribute to the quality or effectiveness of the supplement. 

Another reason why fewer ingredients are better is that it keeps the cost down.

You can read more about how price factors into my scoring system here.

3. Third-party testing and Good Manufacturing Practice certification

When a supplement company wants third-party testing and certification, it pays an outside organization to test for ingredient potency and accuracy.

Getting certified means an independent organization has reviewed the product and determined it complies with safety, quality, and performance standards.

The absence of third-party testing doesn’t immediately mean a poor product. But knowing the dishonest bullshitting going on in the supplement industry, third-party testing gives me peace of mind knowing a product is safe and has — and does — what it says on the box. 

GMP (Good Manufacturing Practice) certification means the manufacturing facilities comply with the rigorous quality standards of regulatory authorities. It covers the entire manufacturing process, including sourcing of raw materials, production processes, packaging, and labeling. 

These guidelines provide minimum requirements that a manufacturer must meet to ensure its products are consistently high in quality.

In short, third-party testing is about the product, and GMP compliance covers the manufacturing.

Read more about third-party testing and GMP compliance here.

4. Energy

Out of all the effects I look for in a pre-workout, this is the one I care about the most. I want to feel psyched and focused for my strength training. And I want to finish without getting the dreaded post-workout caffeine crash.

You can read more about how the energy factors into my scoring system here.

5. Pump

The second most important thing I need from a pre-workout is the pump. The product must have enough L-citrulline (4,000 mg) to increase the blood flow into the muscles I’m working. In most cases, anything less than 6,000 mg, and I’d rather spend my money elsewhere.

Read more about what I look for when scoring the pump.

6. Taste

Let’s face it: Making a decent-tasting pre-workout shouldn’t be that difficult. Yes, a pre-workout with high-quality ingredients in high doses often tastes worse because it’s hard to mask the flavor of the ingredients, but anything less than 8/10 is only acceptable if the product is otherwise exceptional. 

Then again, taste is subjective so don’t get too hung up on this.

You can read more about how taste factors into my scoring system here.

7. Mixability

I need a pre-workout that’s easy to mix in a shaker. That means no powder clumps! I expect something smooth and grit-free that doesn’t get stuck on the side of the shaker. Most pre-workouts add silicon dioxide and calcium silicate as anti-caking agents, so look for that if you’re as annoyed by clumps as I am.

Read more about how mixability factors into my scoring system.

8. Customer experience

In this testing stage, I find and navigate the website, complete the ordering process, and accept delivery, evaluating each company every step of the way. I also review customer service in cases where I have problems with the order. I have high expectations for customer service and will harshly judge brands with missing links in their customer experience.

You can learn more about how customer service factors into my scoring system here.

Conclusion

Transparent Labs BULK pre-workout gets most things right in terms of ingredients with properly dosed L-citrulline and caffeine to deliver energy, focus, and pump. It’s also third-party tested.

However, the flavors aren’t great, and the unnecessary vitamins and minerals in the mix are baffling.

If you can get past the taste issues and don’t mind those random minerals and vitamins, Transparent Labs BULK is a great option that gives you what you need to train with intensity without any hidden blends or underdosed key ingredients. 

This pre-workout is quickly becoming my go-to recommendation for most guys.

FAQs

References

1. Aguiar, A. F., & Casonatto, J. (2022). Effects of citrulline malate supplementation on muscle strength in resistance-trained adults: A systematic review and meta-analysis of randomized controlled trials. Journal of Dietary Supplements, 19(6), 772–790. https://doi.org/10.1080/19390211.2021.1939473

2. Trexler, E. T., Smith-Ryan, A. E., Stout, J. R., Hoffman, J. R., Wilborn, C. D., Sale, C., Kreider, R. B., Jäger, R., Earnest, C. P., Bannock, L., Campbell, B., Kalman, D., Ziegenfuss, T. N., & Antonio, J. (2015). International society of sports nutrition position stand: Beta-alanine. Journal of the International Society of Sports Nutrition, 12, 30. https://doi.org/10.1186/s12970-015-0090-y

3. ​Ismaeel A. (2017). Effects of betaine supplementation on muscle strength and power: A systematic review. Journal of Strength and Conditioning Research, 31(8), 2338–2346. https://doi.org/10.1519/JSC.0000000000001959

4. Kurtz, J. A., VanDusseldorp, T. A., Doyle, J. A., & Otis, J. S. (2021). Taurine in sports and exercise. Journal of the International Society of Sports Nutrition, 18(1). https://doi.org/10.1186/s12970-021-00438-0

5. Deijen, J. B., Wientjes, C. J., Vullinghs, H. F., Cloin, P. A., & Langefeld, J. J. (1999). Tyrosine improves cognitive performance and reduces blood pressure in cadets after one week of a combat training course. Brain Research Bulletin, 48(2), 203–209. https://doi.org/10.1016/s0361-9230(98)00163-4

6. Examine. Choline. https://examine.com/supplements/choline/

7. Guest, N.S., VanDusseldorp, T. A., Nelson, M. T., Grgic J., Schoenfeld, B. J., Jenkins N. D. M., Arent S. M., Antonio, J., Stout, J. R., Trexler, E. T., Smith-Ryan, A. E., Goldstein, E. R., Kalman, D. S., & Campbell, B. I. (2021). International society of sports nutrition position stand: Caffeine and exercise performance. Journal of the International Society of Sports Nutrition, 18(1). https://doi.org/10.1186/s12970-020-00383-4

8. Examine. Theanine. https://examine.com/supplements/theanine/

9. Mitchell, E. S., Slettenaar, M., Meer, N. vd., Transler, C., Jans, L., Quadt, F., Berry, M. (2011). Differential contributions of theobromine and caffeine on mood, psychomotor performance and blood pressure. Physiology and Behavior, 104(5), 816–822. https://doi.org/10.1016/j.physbeh.2011.07.027

10. Gao, L., Ge, W., Peng, C., Guo, J., Chen, N., & He, L. (2022). Association between dietary theobromine and cognitive function in a representative American population: A cross-sectional study. The Journal of Prevention of Alzheimer’s Disease, 9(3), 449–457. https://doi.org/10.14283/jpad.2022.39

11. Hou, C. W., Lee, S. D., Kao, C. L., Cheng, I. S., Lin, Y. N., Chuang, S. J., Chen, C. Y., Ivy, J. L., Huang, C. Y., & Kuo, C. H. (2015). Improved inflammatory balance of human skeletal muscle during exercise after supplementations of the ginseng-based steroid Rg1. PLOS ONE, 10(1). https://doi.org/10.1371/journal.pone.0116387 

12. Janse van Rensburg, C., Erasmus, E., Loots, D. T., Oosthuizen, W., Jerling, J. C., Kruger, H. S., Louw, R., Brits, M., & van der Westhuizen, F. H. (2005). Rosa roxburghii supplementation in a controlled feeding study increases plasma antioxidant capacity and glutathione redox state. European Journal of Nutrition, 44(7), 452–457. https://doi.org/10.1007/s00394-005-0555-x

13. Examine. Boron. https://examine.com/supplements/boron/

14. Examine. Zinc. https://examine.com/supplements/zinc/

15. Examine. Pyridoxine Vitamin B6. https://examine.com/supplements/vitamin-b6/

16. Examine. Black Pepper. https://examine.com/supplements/black-pepper/