Labrada PE1 Review

Labrada PE1

PE1 is Labrada’s most recent pre-workout supplement which contains some pretty standard pre-workout ingredients (Beta-Alanine, Citrulline, etc.) as well as a few stimulants…


[gard group=’1′]

PE1 is Labrada’s most recent pre-workout supplement which contains some pretty standard pre-workout ingredients (Beta-Alanine, Citrulline, etc.) as well as a few stimulants…[Skip to the Bottom Line]


Beta-Alanine is a precursor to the amino acid Carnosine, which functions as a lactic acid buffer capable of reducing fatigue in the working muscle. Though it takes time to accumulate in muscle tissue, Beta-Alanine supplementation, for at least two weeks, is highly effective at increasing muscular Carnosine concentration.

One study in particular that measured the Carnosine levels of sprinters found that individuals with higher muscular Carnosine levels exhibited higher power output in the latter half of a 30m sprint (because they had less lactic acid build-up). Multiple studies have confirmed that Beta Alanine supplementation increases muscular Carnosine in a dose dependent manner. In particular, a 2012 study published in “Amino Acids” found that subjects who consumed 1.6 or 3.2 grams of Beta Alanine daily experienced significant increases in muscle carnosine in as little as two weeks, with the higher dose achieving a higher concentration of Carnosine. The doses used in this study, 1.6 and 3.2g, are the most common doses seen in supplements.

A 2008 study, published in the International Journal of Sports Medicine, noted improvements in power in resistance trained males using 4.8g daily for 30 days. This same 4.8 gram dose was also shown to increase muscular endurance in sprinters in a 2007 study from the “Journal of Applied Physiology”.

PE1 contains 1635mg of Beta-Alanine per serving, towards the lower end of what has demonstrated efficacy in studies, but an effective dose nonetheless.


Citrulline Nitrate simply refers to the amino acid Citrulline fused with Nitric Acid. By combining these two compounds, Citrulline Nitrate is able to convey both the benefits of Citrulline and the benefits of Nitrate. A common claim associated with Nitrate-fused compounds is that the Nitrate portion enhances absorption because Nitrates tend to be highly absorbable (98-100%). However, since there are no studies (not even in animals) assessing the absorption of Citrulline Nitrate compared to L-Citrulline, this is currently just a theory. For now it can only be assumed that Citrulline Nitrate is about the same as consuming L-Citrulline and Nitrates separately, both of which have been shown to enhance endurance and increase exercise capacity at a given work load.

A 2008 study from “The Journal of Strength & Conditioning” found that 8g of Citrulline Malate was able to progressively increase the amount of reps performed later in the workout (by as much as 52%) and significantly reduced muscle soreness.

A 2009 study, published in the “Journal of Free Radical Research”, found that 6 grams of Citrulline Malate given to male cyclists before a race increased “plasma Arginine availability for NO synthesis and PMNs priming for oxidative burst without oxidative damage”.

A 2011 study, the subjects of which were rats, found that supplemental Citrulline increased muscular contraction efficiency (less ATP was required for the same amount of power), in-line with the findings of the above-mentioned human study.

Citrulline is generally considered to be most effective at doses of 6-8g, though it is rare to find that pre-workout supplements (it gets kind of expensive). Theoretically speaking, Citrulline Nitrate may require a lower dose, but as mentioned before, the amount by which the addition of Nitric Acid actually enhances absorption is unknown so there is no Citrulline Malate equivalent dose.

Labrada does not disclose the exact dose of Citrulline Nitrate in the PE1 formula, but considering Citrulline Nitrate shares a 1634mg blend with Arginine AKG, Agmatine, and Creatine, there is most likely no more than 400-600mg (our estimate), far less than the 6g of Citrulline Malate generally used in studies.


Arginine is a non-essential amino acid that acts as a precursor to Nitric Oxide and the AKG (Alpha Ketogluturate) form is alleged to be better absorbed than standard L-Arginine.

However, recent studies indicate Arginine may not be all it’s cracked up to be, with a 2012 study from the “Journal of the International Society of Sports Nutrition” finding that subjects performed worse after receiving 3700mg of Arginine Alpha-Ketoglutarate prior to resistance training, compared to placebo. Due to the relatively small size of this study, it cannot be considered conclusive, but it certainly does not lend credibility to the notion that Arginine AKG is a superior form of Arginine.

While most studies have failed to prove that Arginine (in any form) supplementation increases exercise performance, a 2011 double-blind placebo controlled study from “Sports Medicine” found that supplementation with 6 grams of L-Arginine increased muscle blood volume post-workout, but did not increase intra-workout strength.

Ultimately, the alleged (unproven) benefits of Arginine are the actual (proven) benefits of Citrulline, so we’re not really sure why supplement companies keep insisting that Arginine is of any value in pre-workout supplements. This refusal to admit the facts most likely has to do with the fact that Arginine is much cheaper than Citrulline (on a per gram basis). The amount of Arginine AKG present in the PE1 formula is likely pretty negligible compared to what has demonstrated some partial efficacy in studies.


Agmatine remains very under-researched, despite possessing a variety of health/performance implications. Recently, Agmatine has become quite pervasive in pre-workout supplements because of its alleged ability to regulate Nitric Oxide Synthase (NOS), an enzyme that catalyzes the production of NO from Arginine, and either elevate or reduce its presence, depending on the type of NOS. NOS is a widely misunderstood enzyme, mostly due to supplement companies not properly explaining its function and how that function relates to physical performance. It is largely thought that NOS is the enzyme that “breaks down” NO, when it is actually the enzyme that catalyzes the production of NO from Arginine in the first place.

Nitric Oxide generally has a positive connotation in the bodybuilding/athletic community because it is associated with vasodilation, which clearly has performance/health benefits. However, this beneficial effect of NO only pertains to NO in the blood vessels. Elsewhere in the body (like the brain) NO can inflict damage and actually be quite harmful. So ideally, what we really are after is a way to reduce NO in the areas of the body where it can cause harm, while increasing it in blood vessels where it can beneficially influence physical performance.

It’s important to understand that there are several types of NOS, all which are required for the production of NO. Inducible NOS (iNOS) and Neuronal NOS (nNOS) are considered harmful because they elevate NO in immune cells (causing inflammation) and the brain (causing neuronal damage), while Endothelial NOS (eNOS) is considered beneficial as this is the kind which increases Nitric Oxide in the blood vessels, resulting in vasodilation. Agmatine has been demonstrated to up-regulate eNOS (the “good” NOS) while inhibiting the other NOS enzymes (the “bad” NOS). However, as mentioned above, Agmatine remains under-researched because it is a relatively new entrant in the supplement industry.

Currently, most of the research has been done in vitro, with absolutely no studies regarding the potential physical performance benefits of Agmatine in humans. Because of the lack of human studies, no optimal dose has been established for Agmatine, though average doses in pre-workout formulas are 500-1000mg. PE1 likely contains far less than even 500mg, though since Labrada doesn’t disclose the exact dose, it’s tough to gauge the efficacy.


Creatine has the ability to rapidly produce ATP (cellular energy) to support cellular function (as in exercise). It has been studied more extensively than any other performance enhancing supplement, and has consistently been demonstrated to increase power output as well as muscle size, with maximum benefit achieved at around 8 weeks of consistent supplementation. Creatine can also indirectly reduce lactic acid build since it can be used for energy instead of glucose, and lactic acid is a byproduct of glucose utilization (burning).

Generally speaking, effective daily doses of Creatine are around 5 grams daily, though as low as 2-3 grams has been shown to maintain (but not elevate) muscle Creatine levels. Given that it is listed last in a 1634mg blend, the amount of Creatine in the PE1 formula is extremely negligible and, even at 3 of 4 servings daily, wouldn’t positively influence strength and performance.


Caffeine is a well-established ergogenic aid, oral consumption of which triggers the release of Catcholamines (Noradrenaline, Dopamine, Adrenaline, etc.), generally inducing a state of increased alertness, focus, and perceived energy. A vast multitude of studies have concluded that Caffeine consumption prior to exercise can favorably impact performance and enhance muscle contractibility.

Since habitual Caffeine consumption often leads to tolerance build-up, those seeking to get the most out of their Caffeine-containing pre-workout should limit Caffeine throughout other parts of the day. Labrada discloses that PE1 contains 154mg of Caffeine per serving, not an excessive dose, but may certainly contribute to some noticeable mental stimulation when combined with Synephrine and Yohimbine.


Synephrine acts as a beta-receptor agonist and an alpha-receptor antagonist, the net effect of which is an increase in lipolysis (fat breakdown). Because of this mechanism of action, Synephrine is often compared to the now banned Ephedrine (also a beta-agonist/alpha-antagonist), though it’s important to understand that it is significantly less potent. Fortunately, it’s also much safer (which is why it isn’t banned). A 2011 study, published in the “International Journal of Medicinal Sciences”, found that supplementation of 50mg Synephrine increased the metabolic rate in human subjects without affecting blood pressure or heart rate. This indicates that Synephrine is a safe, but moderately effective, stimulant with fat-burning potential. PE1 contains Bitter Orange Extract standardized for 30% Synephrine, but since we don’t know the amount of Bitter Orange Extract, it’s tough to determine how much Synephrine is actually in the formula. We’d estimate the Synephrine content to be anywhere from 10-20mg.


The primary active component of Yohimbe (Pausinystalia Yohimbe) is Yohimbine, which acts as an alpha-2 receptor antagonist, meaning it inhibits the receptor responsible for blocking lipolysis. By blocking the action of this receptor Yohimbine allows for more lipolysis to occur.

A 2006 study showed that while there were no increases in strength, supplementation induced fat loss in athletes (soccer players). As previously stated, Yohimbine directly acts on alpha-2 receptor, but its fat loss capabilities may also be magnified by its ability to increase the catecholamine neurotransmitters adrenaline and noradrenaline which in turn induce lipolysis. However, its ability to increase Catecholamines may degrade fairly quickly (a few weeks), so for Yohimbine to be truly effective as a weight-loss agent, it must be combined with something that activates the beta-adrenergic receptors in the first place (i.e. caffeine and other stimulants or exercise).

The Yohimbe Bark Extract in PE1 is standardized to 10% Yohimbine, and although we can’t be sure of the exact dose, we’d estimate it contains no more than 1-2.5mg per serving.


PE1 contains a lackluster blend of the usual pre-workout ingredients (Agmatine, Creatine, Beta-Alanine, etc.), for the most part, at pretty ineffective doses. The stimulants (Caffeine, Synephrine, and Yohimbine) present in the formula may help to increase focus and drive, but still don’t do much in the way of differentiating PE1 from other pre-workouts out there. Ultimately, unless the price was seriously reduced, we just don’t see any reason to choose PE1 over any other pre-workouts and will have to give this one a pass.

[expand title=”REFERENCES” tag=”h5″]

  1. Kraemer, William J., and Jeff S. Volek. “Creatine supplementation: its role in human performance.” Clinics in sports medicine 18.3 (1999): 651-666.
  2. Casey, Anna, and Paul L. Greenhaff. “Does dietary creatine supplementation play a role in skeletal muscle metabolism and performance?.” The American journal of clinical nutrition 72.2 (2000).
  3. Thompson, C. H., et al. “Effect of creatine on aerobic and anaerobic metabolism in skeletal muscle in swimmers.” British journal of sports medicine 30.3 (1996): 222-225.
  4. Sax, L. “Yohimbine does not affect fat distribution in men.” International journal of obesity 15.9 (1991): 561-565.
  5. Gurguis, George NM, Bernard J. Vitton, and Thomas W. Uhde. “Behavioral, sympathetic and adrenocortical responses to yohimbine in panic disorder patients and normal controls.” Psychiatry research 71.1 (1997): 27-39.
  6. Drew, Geoffrey M. “Effects of α-adrenoceptor agonists and antagonists on pre-and postsynaptically located α-adrenoceptors.” European journal of pharmacology 36.2 (1976): 313-320.
  7. Wright, Elizabeth E., and Evan R. Simpson. “Inhibition of the lipolytic action of beta-adrenergic agonists in human adipocytes by alpha-adrenergic agonists.”Journal of lipid research 22.8 (1981): 1265-1270.
  8. Ostojic, Sergej M. “Yohimbine: the effects on body composition and exercise performance in soccer players.” Research in Sports Medicine 14.4 (2006): 289-299.
  9. Pérez-Guisado, Joaquín, and Philip M. Jakeman. “Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness.” The Journal of Strength & Conditioning Research 24.5 (2010): 1215-1222.
  10. Bendahan, D., et al. “Citrulline/malate promotes aerobic energy production in human exercising muscle.” British journal of sports medicine 36.4 (2002): 282-289.
  11. Sureda, Antoni, et al. “Effects of L-citrulline oral supplementation on polymorphonuclear neutrophils oxidative burst and nitric oxide production after exercise.” Free radical research 43.9 (2009): 828-835.
  12. Giannesini, Benoît, et al. “Citrulline malate supplementation increases muscle efficiency in rat skeletal muscle.” European journal of pharmacology 667.1 (2011): 100-104.
  13. Graham, T. E., and L. L. Spriet. “Metabolic, catecholamine, and exercise performance responses to various doses of caffeine.” Journal of Applied Physiology 78.3 (1995): 867-874.
  14. Graham, Terry E. “Caffeine and exercise.” Sports medicine 31.11 (2001): 785-807.
  15. Mun, Chin Hee, et al. “Regulation of endothelial nitric oxide synthase by agmatine after transient global cerebral ischemia in rat brain.” Anatomy & cell biology 43.3 (2010): 230-240.
  16. Morrissey, Jeremiah J., and Saulo Klahr. “Agmatine activation of nitric oxide synthase in endothelial cells.” Proceedings of the Association of American Physicians 109.1 (1997): 51-57.
  17. Abe, Kazuho, Yuzuru Abe, and Hiroshi Saito. “Agmatine suppresses nitric oxide production in microglia.” Brain research 872.1 (2000): 141-148.
  18. Zhang Wax, Benjamin, et al. “Acute L-arginine alpha ketoglutarate supplementation fails to improve muscular performance in resistance trained and untrained men.”Journal of the International Society of Sports Nutrition 9.1 (2012)
  19. Zhang Alvares, Thiago S., et al. “L-Arginine as a Potential Ergogenic Aidin Healthy Subjects.” Sports Medicine 41.3 (2011): 233-248.
  20. Kaats, Gilbert R., et al. “A 60day double-blind, placebo-controlled safety study involving< i> Citrus aurantium(bitter orange) extract.” Food and Chemical Toxicology 55 (2013): 358-362.
  21. Stohs, Sidney J., et al. “Effects of p-synephrine alone and in combination with selected bioflavonoids on resting metabolism, blood pressure, heart rate and self-reported mood changes.” International journal of medical sciences 8.4 (2011): 295.
  22. Haaz, S., et al. “Citrus aurantium and synephrine alkaloids in the treatment of overweight and obesity: an update.” Obesity reviews 7.1 (2006): 79-88.
  23. Graham, Terry E., Danielle S. Battram, Flemming Dela, Ahmed El-Sohemy, and Farah S.L. Thong. “Does Caffeine Alter Muscle Carbohydrate and Fat Metabolism during Exercise?” Applied Physiology, Nutrition, and Metabolism 33.6 (2008): 1311-318.
  24. Hoffman J, et al. Beta-alanine and the hormonal response to exercise. Int J Sports Med. (2008)
  25. Stellingwerff, Trent, et al. “Effect of two β-alanine dosing protocols on muscle carnosine synthesis and washout.” Amino Acids 42.6 (2012): 2461-2472.
  26. Wilson, Jacob M., et al. “Beta-alanine supplementation improves aerobic and anaerobic indices of performance.” Strength & Conditioning Journal 32.1 (2010): 71-78.
  27. Sale, Craig, Bryan Saunders, and Roger C. Harris. “Effect of beta-alanine supplementation on muscle carnosine concentrations and exercise performance.” Amino acids 39.2 (2010): 321-333.
  28. Suzuki, Yasuhiro, Osamu Ito, Naoki Mukai, Hideyuki Takahashi, and Kaoru Takamatsu. “High Level of Skeletal Muscle Carnosine Contributes to the Latter Half of Exercise Performance during 30-s Maximal Cycle Ergometer Sprinting.” The Japanese Journal of Physiology 52.2 (2002): 199-205.

[/expand] exists to educate the supplement community and seperate the science from the hype.

Click to comment
To Top