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Transparent Labs LEAN Pre-Workout Review

Transparent Labs Lean pre-workout is designed to help you shed pounds, have more energy for training, and enhance other factors of performance.
Matthew Magnante, ACE
We provide honest reviews based on a thorough, multi-point testing methodology. We do earn a commission if you purchase through our links, supporting our independent product assessments. View our disclosure for more details.

Transparent Labs products are hot right now. But not just because they disclose what they put in in their products and avoid artificial sweeteners, colors, and harmful additives. This is a company that seems to do everything right and we’re not the only ones who think so.

We recently reviewed their Lean pre-workout product that’s designed to help burn fat while providing a sustainable energy boost, some cognitive benefits, and more. 

According to the product information on their website, “Lean was developed for a single purpose – to be the most exceptional “cutting” pre-workout supplement available for men and women alike”. This is great news as it appeals to a larger audience.

The Lean product also offers thyroid support which is interesting. But allow us to break the product down in its entirety so that you can learn everything you need to about this pre-workout. We tried out the Blue Raspberry option, although they have a few great flavors to choose from…

Note: Consult with a physician prior to considering supplementation with this product if you have any medical conditions or are taking any medications. It’s definitely not a suitable product for pregnant women, especially without the approval of a medical professional and we don’t recommend it for children.

Also, each serving of lean contains 180mg of caffeine per serving. While this isn’t a crazy amount, it’s still a lot if you don’t regularly have caffeine. Therefore, you should have already built up a decent tolerance to it before using this product. Otherwise, you could experience unpleasant side effects.

Transparent Labs LEAN Review – A Potent Energy-Boosting “Cutting” Formula?


  • No proprietary blends 
  • Low-carb (1g per serving)
  • Naturally-sweetened 
  • No sugar
  • No artificial colors/dyes
  • No artificial sweeteners or colors
  • Non-GMO
  • Gluten-free
  • No preservatives
  • Vegan-friendly
  • Lab-tested


  • Pricey
  • 180mg caffeine may not be enough for hardcore users
  • Not all ingredients are entirely proven

Transparent Labs LEAN Pre-Workout Coupon

Transparent Labs LEAN Pre-Workout Coupon

Transparent Labs LEAN Pre-Workout Coupon

Transparent Labs LEAN Pre-Workout - A potent energy-boosting "cutting" formula? Check out our breakdown and final opinion on this super hot product.

Key Features

  • 180mg caffeine per serving for an effective, safe energy boost
  • 6,000mg citrulline for big pumps
  • 2,500mg BetaPure(TM) betaine anhydrous for muscle gains and performance
  • 2,000mg BCAA for improved recovery 
  • 1,500mg beta-alanine for increased exercise capacity
  • Thyroid support
  • Fat-loss support

Main Ingredients/Potential Benefits

Transparent Labs PreSeries LEAN Pre-Workout
Transparent Labs PreSeries LEAN Pre-Workout

Transparent Labs Lean pre-workout contains a combination of strategically-combined ingredients that they trust will elicit the effects you hope to experience with a similar product. We’ve provided information on the key ingredients used to hopefully better inform you about what each offers.

Big Pumps/Improved Performance/Recovery Support

Citrulline Malate 2:1 6,000mg

An amino acid found in the body and precursor to l-arginine, l-citrulline has positive effects on vascular health, protein metabolism, and lipid metabolism. In fact, l-citrulline is actually more effective at increasing l-arginine levels and NO synthesis. (1)

One scientific publication explained that it has cardiometabolic health benefits via multiple pathways. In addition, its use was found to boost growth hormone levels after exercise. (2)

Also, a study conducted on cyclists found that l-citrulline can increase the duration of cycling by an additional 12% if you hadn’t otherwise taken it. There are also scientific reviews that have shown increased anaerobic performance such as with weightlifting, in addition to significantly reducing post-exercise soreness.

BetaPure(TM) betaine anhydrous 2,500mg

From what we’ve seen so far, it’s safe to say betaine elicits some impressive results when supplemented. In one study, twenty-three equally-matched subjects were given either a placebo and betaine of 2.5 g/day in combination with a 6 week periodized training program consisting of 3 two-week micro-cycles. (3)

Their bench press and squat training volumes were measured, in addition to their arm and thigh sectional area, fat mass, and lean body mass.

Arm cross-sectional area increased significantly in the betaine group and not the placebo group. Thigh cross-sectional area saw no changes for either group. The back squat was significantly improved in both groups. The betaine groups saw significant improvements in the bench press during specific microcycles.

Body composition was significantly improved in the betaine group and not the placebo group. Improvements in vertical jump power were also seen in the betaine group. 

Transparent Labs PreSeries LEAN Ingredients
Transparent Labs PreSeries LEAN Ingredients

BCAA 2:1:1 (Instantized) 2,000mg

BCAAs or branched-chain amino acids make up three ( leucine, isoleucine, and valine) of the 9 essential (the body can’t make them) amino acids that our bodies need to make proteins. Without a sufficient amount of all nine essential amino acids, you won’t maximize protein synthesis which preludes muscle growth. (4)

That also means just supplementing with BCAAs will not do the job alone. But it’s definitely important to note that leucine is the most important BCAA for protein synthesis, and according to research, it has this effect via a specific pathway. (5, 6)

But besides the muscle-building benefits, branched-chain amino acids have also shown to have positive effects on exercise fatigue, soreness, and recovery. 

Any form of rigorous training or physical activity will eventually cause fatigue to some degree. The muscles use BCAAs during activity, and when levels get too low, the amino acid tryptophan increases, which is then converted into serotonin and this results in fatigue. (7)

But BCAAs seem to have a positive effect on sustaining activities for longer durations. In addition, research has found that it improves muscle recovery, DOMS (delayed onset muscle soreness), which occurs several hours following intense training, and even immune system health. (8, 9, 10)

Note: Lean contains fermented vegan BCAAs. 

Beta-alanine 1,500mg

Beta-alanine is a non-essential amino acid that produces carnosine which is known to reduce the amount of lactic acid in the muscles. High levels of lactic acid build-up in the muscles during exercise and this causes pain and discomfort or the burning that you experience when pushing yourself. (11)

Carnosine acts as a buffer against lactic acid build-up and allows you to not only hold off the pain but it reduces fatigue which improves exercise capacity. (12)

Beta-alanine is also known for causing “tingles” after you take it in supplement form but this is nothing to be concerned with. 

Cognitive Enhancement and Big Energy

N-acetyl l-tyrosine 600mg

Tyrosine’s role in Lean pre-workout is to enhance factors of cognitive function. This amino acid may improve focus, memory, the ability to perform under stress, and even mood. Although, these effects are likely more effective when there is a physical stress.

Otherwise, there isn’t much proof that it can enhance these factors.

It’s also important to note that the N-acetyl l-tyrosine form of tyrosine has a lower conversion rate in the body than the free-form counterpart. (13)

L-theanine 360mg

L-theanine is an amino acid naturally found in green teas. There’s sufficient evidence for its calming effects in addition to other important factors of cognitive health. 

One “randomized, placebo-controlled, crossover, and double-blind trial” set out to determine the effects of four weeks of l-theanine supplementation for cognitive function and stress. 30 volunteers with no major psychiatric illness were given either 200mg/day l-theanine or placebo tablets.

In the end, stress symptoms such as depression, anxiety, and sleep issues improved, as did cognitive function (e.g. verbal fluency and executive function). In addition, l-theanine intake resulted in the reduction of sleep quality problems (disturbances in sleep latency, sleep disturbance, and use of sleep medication). (15)

Caffeine anhydrous 180mg

Caffeine is a potent nervous system stimulant and no one could dispute that. And it’s a well-known fact that you won’t get the same effects with non-caffeine pre-workouts as you will with a product that supplies a hefty dose. 

However, it’s also the one product you need to be most careful with. If you haven’t built-up a solid tolerance to caffeine and try to take a full or even half a dose of most pre-workouts, there could be adverse side effects. Lean contains 180mg which isn’t as much as what many products have. 

However, it’s still a decent amount especially for those who haven’t taken a pre-workout. Although, the company made sure to not overdo it compared to other products that include unnecessary amounts. According to Mayoclinic, most healthy adults shouldn’t exceed 400mg caffeine per day. (15)

When taken in safe dosages, caffeine has great energy-boosting and cognitive-enhancing benefits. 

Transparent Labs combines l-theanine with caffeine which can have pronounced effects on mental performance without jitters or crashing.

Guggulsterones 75mg

Guggulsterones are a plant sterol found in the resin of the guggul plant. have shown to reduce food intake and body weight while reducing levels of the hunger hormone “ghrelin”, glucose, and triglycerides in rats. In addition, this substance increased dopamine, serotonin, and plasma leptin. (16)

It may have effects on inflammation and other health markers in humans based on research. But the evidence for humans isn’t really sufficient to conclude anything. There definitely needs to be more research. 

Mucuna pruriens (seed) (min. 40% l-dopa) 70mg

Mucuna pruriens is a medicinal plant that contains levodopa or L-dopa (precursor to dopamine). It’s included for its cognitive-enhancing properties. Mucuna pruriens is also therapeutic for Parkinson’s and nervous disorders which is likely due to its antioxidant activity. Plus it’s nutrient-rich. (17)

L-norvaline 60mg

L-norvaline is used to extend nitric oxide release to sustain pumps during training through enhancing the blocking effect of an inhibiting substance. 

Although it may be an effective ingredient, there has been some debate about whether or not it may negatively affect the brain. Although, one 2018 study concluded that it’s a “potentially beneficial multifunctional agent and a potential drug for the treatment of Alzheimer’s disease (AD)“.  AD causes cognitive decline and therefore, you could see why there’d be some conflict about the belief that L-norvaline may be bad for the brain. (18)

Not only that though, other publications believe the information on the potential negative effects could be overstated.


Transparent Labs LEAN Pre-Workout Coupon

Transparent Labs LEAN Pre-Workout Coupon

Transparent Labs LEAN Pre-Workout Coupon

Transparent Labs LEAN Pre-Workout - A potent energy-boosting "cutting" formula? Check out our breakdown and final opinion on this super hot product.

Weight loss support

Synephrine HCI 50mg

Synephrine is a protoalkaloid found in bitter orange (Citrus aurantium) which is used for weight loss, performance, and cognitive function. There have been concerns about synephrine because of its similar structure to ephedra which was banned in 2004.

But apparently, approximately 30 studies have proven synephrine and bitter orange extract do not have negative effects on the heart and do not act as stimulants in commonly used doses. (19)

One piece of scientific literature found that synephrine can increase the rate of fat oxidation and reduce the rate of carbohydrate oxidation during exercise. This was determined when exercise was performed at low to moderate intensities. (20)

This means it can help the body to go straight to the fat cells for energy. 

Hordenine 25mg

Hordenine is found in barley (Hordeum vulgare) which is similar to the bitter orange extract that contains synephrine. It’s also used for the same reasons and is said to be a mild stimulant that may work well with other substances for pronounced effects.

Although, there isn’t much evidence for its effects on humans and in oral form especially. 

Bioperine (black pepper extract) (95% pipeline) 5mg 

Bioperine is used in many supplements to improve nutrient bioavailability 


  • Iodine (iodine chelate) is essential for the health of the thyroid hormones thyroxine (T4) and triiodothyronine (T3). The thyroid plays an important role in metabolic activity, enzymatic activity, and protein synthesis. 
  • Zinc (zinc AAC), an essential mineral, needed for protein synthesis, Immune health, cell division, enzyme activity, wound activity, and also growth and development. 
  • Selenium (L-selenomethionine) is a trace mineral that plays critical roles in many health functions such as reproduction, DNA synthesis, and thyroid hormone function, plus it has antioxidant properties that protect cells from damage. 
  • Copper (copper AAC) works with another mineral iron, to create red blood cells that transport oxygen to the body’s tissues for carbon dioxide which is released by the lungs. Like other minerals, copper is needed for muscle, nerve, blood cell, immune system, and bone health. You also need copper to help with the absorption of iron. 
  • Chromium (chromium picolinate) is a trace mineral that can enhance the effects of insulin which is the hormone that allows us to metabolize and store macronutrients (protein, carbs, and fat). Without insulin, you wouldn’t be able to use carbs as energy and you’d store too much fat.

Additional Ingredients 

The additional ingredients include natural flavor (1,150mg), stevia (450mg), calcium silicate (230mg), and silicon dioxide (230mg).

Stevia is a nonnutritive natural sweetener and many people will definitely appreciate this about the product. However, there are also many users who aren’t necessarily a big fan of how stevia tastes. And this will definitely come down to personal preference. 

It’s deemed safe by the FDA and may actually help to regulate glucose levels and improve insulin sensitivity. (21)

Then you have calcium silicate and silicon dioxide which are just used as anti-caking agents for the powder which don’t contribute to anything else. 

How to use

LEAN should be taken at least 20-30 minutes prior to your workout. The product label recommended starting with 1/2 scoop and 6-8 fl. oz of water to assess tolerance 6-8 fl. oz. If using a full scoop, mix it in 12-16 oz of water.


As you’d probably expect with a pre-workout at this price point, the powder mixes pretty well. You can shake it up or use a spoon and mix it although you’d need a little extra mixing with a spoon to dissolve all of the powder.


I tried the Blue Raspberry and although it was a little sour tasting, the overall flavor is not bad at all. Although, I did take a half scoop with about 8 ounces of water so I may not have had the most potent experience. Still, though, it’s definitely palatable.

PreSeries LEAN Pre-Workout
PreSeries LEAN Pre-Workout


As the case with most product offerings, the more you buy, the more you save. 

If you buy one tub, you’ll be paying $49 for 30 servings which comes to about $1.63 per serving. This is definitely a bit more than a lot of exercisers would like to pay for a pre-workout supplement. Then if you buy two tubs, you’ll spend $5 less for your order, and with 3 tubs you’ll save $10 compared to if you bought one tub.

Still, even if you buy more than one tub, it’s costly.

We’re not at all saying that this pre-workout is not worth the extra cash. It definitely has a long list of respectable-dosed ingredients and a respectable amount of caffeine. Not to mention, they avoid junk ingredients, are transparent (no proprietary blends), and just really have a great reputation right now. 

But you can definitely find products for $10-20 cheaper that’ll contain as much or more caffeine with several scientifically-proven ingredients as well. However, we can’t promise the overall quality will be the same. 

In addition, this formula is designed for those with the goal of cutting and while giving you a healthy dose of caffeine in a serving without overdoing it as many products do. 

Pricing per tub/s:

  • 1 tub: $49
  • 2 tubs: $89
  • 3 tubs: $119

Transparent Labs LEAN Pre-Workout Coupon

Transparent Labs LEAN Pre-Workout Coupon

Transparent Labs LEAN Pre-Workout Coupon

Transparent Labs LEAN Pre-Workout - A potent energy-boosting "cutting" formula? Check out our breakdown and final opinion on this super hot product.

Is Lean Pre-Workout Worth The Buy?

We wouldn’t hesitate to recommend Lean pre-workout. It’s a very good product made with quality ingredients, and there are no proprietary blends trying to hide anything. In addition, there are no artificial flavors, colors, or sweeteners used in this product. 

We broke down the formula and found many potentially effective ingredients in addition to the ones that are standard in pre-workouts. It’s designed to help cut and maintain muscle mass of which we think it could possibly be effective for. Although, we’d say use it with realistic expectations because unless you do the work, no natural supplement will either. 

It’s a bit pricey like we explained, but we really like what Transparent Labs is doing right now, and we’re confident they are genuinely concerned with providing top-notch, quality products. 

Overall Rating 

  • Ingredients: 8.25/10
  • Taste: 8/10
  • Mixability: 8.75/10
  • Price: 8/10

Final Thoughts

Transparent Labs products usually don’t disappoint and we didn’t expect their Lean pre-workout to either. It’s a top-notch option that contains ingredients made to help assist with the fat-burning and muscle-preserving process while giving a nice burst of energy that isn’t over the top. 

While it may not be the perfect product or the cheapest, it’s definitely worth giving a try!

If you have any questions about this article, please feel free to contact Matthew Magnante by leaving a comment below.

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The Review

LEAN Pre-Workout

8.5 Score

Transparent Labs Lean pre-workout is designed to help you shed pounds, have more energy for training, and enhance other factors of performance.


  • No proprietary blends
  • Low-carb (1g per serving)
  • Naturally-sweetened
  • No artificial sweeteners or colors
  • Gluten-free
  • Vegan-friendly


  • Pricey
  • 180mg caffeine may not be enough for hardcore users
  • Not all ingredients are entirely proven

Review Breakdown

  • Ingredients
  • Mixability
  • Effectiveness
  • Taste
  • Price

LEAN Pre-Workout DEALS

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Matthew Magnante, ACE
Matthew Magnante, ACE
Matthew is an ACE (American Council On Exercise) certified fitness professional who has had a passion for fitness since elementary school and continues to research and learn how to build muscle effectively through training and diet. He also loves to help others to achieve their fitness goals and spread the knowledge where needed. Matthew's other passions include learning about mindfulness, strolling through nature, traveling, and always working to improve overall.
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