Castle Bravo is the pre-workout equivalent of mutually assured destruction and packed with enough stimulants to put the fear of God almighty into anyone that comes across you. As Oppenheimer once said, “come for I am death, the destroyer of the worlds.” Drop a f$#*ing bomb on your next workout.
† These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnore, treat, cure, or prevent any diseases.
L-Citrulline
Citrulline is a non-essential, non-protein amino acid that forms during the urea cycle and forms ornithine when combined with carbon dioxide. Citrulline is also a critical source of endogenous (natural) arginine, as it is rapidly and efficiently converted to arginine in the vascular endothelium and other tissues.
Citrulline’s benefits have been shown to be greater than its parent compound. While arginine undergoes direct hepatic (liver) metabolism through the enzyme arginase, citrulline bypasses hepatic metabolism entirely and it is delivered straight to the bloodstream. The result is that gut absorption and plasma (blood) bioavailability studies comparing citrulline and arginine have shown two things. First, that citrulline is less readily destroyed and has greater absorption than arginine. Second, that citrulline supplementation increases arginine levels more effectively than arginine supplementation itself.
This translates to promising results. For example, animal studies show a significant increase in anaerobic performance at a 250mg/kg/day serving of citrulline, while studies in humans implicate citrulline in both aerobic and anaerobic performance increases. As a critical part of the urea cycle, citrulline’s performance benefits are thought to be a result of its role in ammonia clearance. Citrulline is implicated in reducing the oxygen cost of muscle processes, along with increasing the rate of post-exercise ATP and phosphocreatine replenishment. As ATP and phosphocreatine are the body’s ‘exercise fuel,’ this may result in citrulline delaying time to exhaustion in aerobic and anaerobic exercise.
Beta Alanine
Carnosine is a bit of an odd duck: we know that it is crucial for muscle function, and that dietary sources of carnosine are essential, but we do not know precisely how it is working. Moreover, for decades, we had no idea how to increase intramuscular concentrations, as exogenous carnosine sources degraded in the body so fast as to be effectively useless.
Enter beta-alanine. Simply a different iteration of one of the amino acids that comprises carnosine itself (alanine), beta-alanine has proven to be the most effective means of significantly increasing intramuscular concentrations of carnosine – and therefore of promoting all of carnosine’s various beneficial effects on muscle performance. If that were not enough, beta-alanine has also demonstrated beneficial physiological effects independent of its parent compound. To understand why, though, we need to first understand some of the basics behind carnosine itself.
Carnosine, a cytoplasmic dipeptide synthesized from the precursors L-histidine and l-alanine, is present in high concentrations in skeletal muscle and plays a pivotal role as a, “chemical buffer” in myocytes (muscle cells). It has long been known that carnosine concentrations are highest in glycolytic, rather than oxidative muscle fibers (roughly speaking, explosive vs., endurance muscle fibers, respectively), and thus long hypothesized that this amino acid is required for sustained performance during supramaximal exercise. Recent research demonstrates that carnosine exerts its physiological effects in long hypoxic (low oxygen) drives by functioning as a high-capacity pH buffer in skeletal muscle, preventing the pH ratio of plasma from dropping too low – and therefore preventing crucial pH-dependent processes such as protein synthesis from being inhibited by acidosis.
Despite its critical role in skeletal muscle anaerobic performance, intramyocellular synthesis of carnosine is rate-limited by the availability of l-alanine. Unfortunately, most of the literature demonstrates that attempting to increase intramuscular levels of carnosine via either direct carnosine or alanine supplementation is largely ineffective due to carnosine/alanine pharmacokinetics. Enter beta-alanine. Research with beta-alanine demonstrates consistent and dose-dependent increases to intramuscular carnosine concentrations with beta-alanine supplementation, with certain studies showing an increase of 40-60% with chronic administration. These same literatures reveal a synergistic effect of exercise on beta-alanine supplementation, whereby the muscle adaptive changes associated with resistance training promote further intramuscular carnosine production in response to beta-alanine supplementation.
In simpler language, this essentially means that beta-alanine is a dietary supplement that promotes its own effects in combination with exercise. As you exercise, you simultaneously intensify beta-alanine’s physiological actions – both directly, as well as in the production of intramuscular carnosine. Once ingested, beta-alanine’s exercise-specific beneficial activity is well-established. Elevation of intramuscular carnosine content via beta-alanine supplementation has been shown to improve performance in the following ways.
Increases to total muscle power output in both acute and chronic trials, suggesting that beta-alanine’s most significant benefit is to those engaging in power-dependent resistance training.
In total, a significant body of research exists to suggest that beta-alanine may significantly increase muscle power output, strength, training volume and output, overall performance in hypoxic (oxygen-deprived) conditions and peak VO2 max (oxygen holding capacity).
These myriad benefits make beta-alanine both one of the most-studied, and most well-rounded dietary supplements. Beta-alanine not only has direct, actionable physiological effects, but also promotes critical muscle physiologic adaptations that promote its own effects.
Peak O2® (Cordyceps (Cordyceps militaris), Reishi (Ganoderma lucidim), King Trumpet (Pleurotus eryngii), Shiitake (Lentinula edodes), Lions Mane (Hericium erinaceus), and Turkey Tail (Trametes versicolor)
PeakO2® is an organic-certified combination of six Ayurvedic mushroom strains extracted for their principal bioactives (Cordyceps militaris (Cordyceps), Ganoderma lucidim (Reishi), Pleurotus eryngii (King Trumpet), Lentinula edodes (Shiitake), Hericium erinaceus (Lions Mane), and Trametes versicolor (Turkey Tail).
The results of several human clinical trials on this compound suggest that it may meaningfully and dose-dependently impact several key metrics in exercise performance and physiology. A recent trial on 13 healthy, exercising adults consuming either 1.3 grams of PeakO2® or placebo, for example, demonstrated significant increases to oxygen kinetics, aerobic power, and time to fatigue. In the adults receiving the 1.3g of PeakO2® for three weeks, VO2-max (a measure of aerobic capacity) increased by 11% as compared to 1.8% in placebo; TTE (total time to exhaustion) increased by 8.2%; and peak power increased by 10%.
The results were similar in an additional study with 40 healthy adults, provided both low and high-dose PeakO2® for 28 days and compared with placebo. In this trial, participants receiving the mushroom extract experienced statistically significant increases to both VO2max and heart-rate economy – suggesting that PeakO2®’s effects are both systemic and cumulative. That is, not only does PeakO2® exert its effects on the entirety of the human cardiovascular system – likely due to the multiple mechanisms of action in the mushroom blend – but these effects accumulate over time.
These results suggest that PeakO2® may have beneficial effects on:
As the mushrooms contained in this compound are also adaptogens, they will also increase the efficacy of the other ingredients in Castle Bravo. Making the addition of PeakO2® both a physiological and economical decision.
L-Tyrosine
Tyrosine is amongst a class of amino acids known as ‘non-essential’ amino acids, so called because the body can produce them endogenously, and it is therefore not essential to consume dietary tyrosine. That said, tyrosine is also what is known as a conditionally-essential amino acid; conditionally-essential because, along with glucose and ammonia, the synthesis of tyrosine additionally requires adequate levels of phenylalanine. Once synthesized, tyrosine is one of the most critical amino acids, given its prominent role as a substrate in the synthesis of the catecholamines dopamine, norepinephrine, and epinephrine, in addition to both T3 (triiodothyronine) and T4 (thyroxine) thyroid hormones.
In studies on stress modulation, tyrosine has been demonstrated to reverse stress-induced norepinephrine depletion and the depressant-behavioral effects normally associated with it. In simpler terms, tyrosine may, in certain conditions, dampen the extent to which norepinephrine is removed from the bloodstream during a stress event. In simpler terms still, tyrosine may help to mitigate the sense of depletion and fatigue felt at the end of a workout.
Tyrosine may also play important metabolic functions, mostly related to its role in synthesizing compounds which stimulate the nervous system. While not traditionally considered a sympathomimetic amine, studies which have co-administered tyrosine and stimulants demonstrate a synergistic effect. These studies suggest that tyrosine may potentiate the effects of both endogenous and supplemental norepinephrine and its mimetics (in the case of exogenous use) with respect to lipolysis, thermogenesis, and energy expenditure. Meaning that tyrosine may play a role in assisting norepinephrine to break up triglycerides and increase body heat transiently.
Caffeine Anhydrous
Caffeine is one of the most widely consumed, and perhaps one of the most reviewed, psychoactive compounds. Its physiological effects in a range of areas have been well-documented, including exercise performance, information processing, alertness and mood enhancement, attention, and awareness, along with its anti-lipogenic and lipolytic abilities.
Most importantly to Castle Bravo, caffeine has been shown to have significant effects on exercise performance, even with ingestion in servings as small 3 to 9mg/kg/bw/day (the equivalent of 2 cups of standard coffee, for a 170lb male). In endurance training, possible explanations for caffeine’s performance-enhancing effects lie in its metabolic effects on both lean and fat tissue. It is suggested that caffeine’s potent lipolytic (the breakdown of fat tissue into fatty acids) and oxidative (the actual ‘burning’ of fat) action allow the body to utilize these sources during prolonged submaximal exercise. Consequently, muscle glycogen is spared and available for use later in the training session. Practically speaking, this means caffeine is forcing your body to preferentially use fat tissue as a fuel source, while sparing the glycogen which gives you the full-bodied look!
In short-term exercise, caffeine’s demonstrated role in the inhibition of cyclic AMP- phosphodiesterase’s (PDE), adenosine receptor antagonism, and adrenoreceptor agonism come into play. These three pathways collectively stimulate lipolytic activity, boost fat metabolism, increase metabolic rate and energy expenditure, and regulate the body’s thermogenic activity. The practical results of activating these pathways are increases to the contractile force of both cardiac and skeletal muscle (harder flexion), an increase in energy expenditure (freeing up more caloric energy to be used in contraction), dilation of vasculature (better blood flow), and improvements to both nitrogen retention and skeletal muscle protein synthesis (key components to muscle building).
Alpha-GPC 50% (L-alpha-glycerylphosphorylcholine)
Of the known choline pro-drugs or precursors, Alpha GPC appears to have exert the greatest influence on circulating choline levels. Choline is an essential nutrient involved in numerous metabolic pathways, including DNA regulation and repair, protein function, and metabolism. Perhaps most importantly, the critical neurotransmitter acetylcholine is produced directly from free choline via cholinergic neurons. Acetylcholine is then responsible for several functions itself, most crucially as the compound which induces muscular contraction, and as the neuromodulator partially responsible for modulating risk/reward, arousal, and enhancing memory.
Choline’s essential role as a substrate for acetylcholine, and therefore brain development, is well documented in animal models. These studies demonstrate that levels of free maternal choline have a direct and fundamental impact on prenatal brain development, with the enhancements or deficits lasting into adulthood. Choline’s enhancing effect is particularly prominent in the hippocampus. In humans, the hippocampus is primarily involved in the consolidation of memory (taking short, episodic memory and translating it into long-term memory) and the learning of new information. Acetylcholine is a critical component in these processes, as mentioned above, and choline may therefore play a potential role in these processes as well by providing the substrate for acetylcholine synthesis.
Whether through these, or other independent mechanisms, a recent trial using Alpha GPC demonstrated a statistically significant increase to power output. In a placebo-controlled, double-blind, randomized trial, 14 healthy volunteers, split into an Alpha GPC or placebo group, were tested on various exercises. In comparison to the placebo group, the Alpha GPC group experienced a 14% increase to bench press. The researchers hypothesize that the peak power increase was the result of a substantial acute increase to growth hormone, one of the observed effects of Alpha GPC supplementation.
Pine Bark Extract (Pinus pinaster) (95% Proanthocyanidins)
Pine bark extract can have an impact on nitric oxide (NO) levels in the body, which are responsible for vasodilation and improving blood flow. It can also control oxidative stress by scavenging reactive oxygen and nitrogen species and suppressing production of peroxides thus improving recovery rates. Pine bark contains bioflavonoids that act as antioxidants, which help protect the body from oxygen waste and other biproducts that can cause cell damage. A 2020 study examined the impact of pine bark extract on exercise performance and recovery in test subjects over the span of 14 days. Metrics included presence of muscle damage, oxidative stress, and inflammation. Results in the 20 test subjects revealed that pine bark extract may help protect the muscle from negative effects of free radicals. With the dual benefits of increased nitric oxide and improvements in recovery muscle health, pine bark extract can be a useful addition to any preworkout formula, which is why we included it in ‘Merica Labz Castle Bravo.
Caffeine Citrate (yields 50% caffeine)
Caffeine citrate is not generally seen in the typical sports performance area. It is more commonly prescribed for premature infants for a short time for the treatment of apnea of prematurity. Apnea of prematurity occurs when a premature infant does not breathe for 15-20 seconds during sleep. In addition to this caffeine citrate can at times be prescribed for migraines in some individuals.
Recently caffeine citrate has gained some popularity in sports performance as it appears to be able to raise blood caffeine levels faster than other caffeine sources. This allows for a quicker feeling of increased energy. For example, typical caffeine levels peak at about 60-120 minutes post ingestion of caffeine anhydrous, whereas blood levels peak around 30 minutes post-ingestion for caffeine citrate. The one drawback to caffeine citrate is that it provides 50% less caffeine per dose than caffeine anhydrous. The specific blend of caffeine sources we have used in Castle Bravo complement each other through differing release times, meaning you will have a quick and effective stimulant feeling with caffeine citrate, as well as plenty of caffeine anhydrous, to give you the quick hitting and long-lasting energy you need to get through your workouts.
ElevATP® (Ancient Peat Extract and Apple Extract) (Fruit)
Adenosine triphosphate and other ATP metabolites are involved in several biological processes including cardiac function, blood flow, muscle contraction and neurotransmission. ATP is the primary molecule that acts as a carrier for energy within cells. It has also often been studied that increased levels of ATP have shown increases in health and performance. Supplementation with exogenous ATP has often shown its ability to increase ATP concentrations in blood. Oral supplementation with ancient peat and apple extracts have exhibited their ability to increase intracellular and intramuscular ATP levels. ElevATP® is a blend these specific polyphenols that works to increase endogenous ATP levels without a simultaneous increase in serum lactate. The significance of this is that usually with an increase in endogenous ATP there is an increase in intracellular free radicals. When these free radicals are not present, oxidative stress is mitigated and there is more potential for the beneficial increases in ATP to take center stage. These increases of ATP are essential as when available energy is increased it can have positive benefits in terms of increased power, strength, and overall exercise performance. One study looked at dosing ElevATP® against placebo and showed that the group who received ElevATP® saw a blood ATP increase of 45% on average along with no increase in oxidative blood glucose. This type of result has been shown repeatedly in studies and has given ElevATP® the reputation to be a beneficial compound for the goals of improving endurance, strength, power, and other training specific adaptations.
Theobromine HCl
Theobromine, one of the main methylxanthine compounds found in cocoa is primarily effective in the increase of nitric oxide to in the blood stream, which is beneficial to produce the “pump” when ingested pre-workout. Another reaction that can be seen with theobromine is dilation of blood vessels. This can increase blood flow during vigorous exercise leading to increased time to exhaustion but also can pose benefits to individuals who suffer from high blood pressure. Theobromine also has a very high bioavailability and ability to stay in the body for extended periods of time (7-8 hours). Several studies have also looked at the effects of theobromine on human subjects and results have shown its ability to reduce oxidative stress on cells and regulation of gene expression.
Synephrine HCl
Synephrine is a naturally-occurring alkaloid with adrenergic agonist activity, structurally related to epinephrine, norepinephrine, ephedrine, and other compounds with a phenethylamine base structure. Despite its chemical similarity to these compounds, synephrine in its various isomers exerts unique effects on adrenergic receptors and the human body, in general.
Synephrine exists in three isomer forms: para-, meta- and ortho-synephrine. The molecular changes between the three isoforms are minute, but even this small change results in significant alterations to each isomer’s physiological and pharmacokinetic profile. Two of synephrine’s isomers, both p- and m-synephrine, have been shown to naturally occur in mammals (in low concentrations). As a sympathomimetic, synephrine has been the subject of numerous trials, assessing its effects on weight management, thermogenesis, metabolic rate, and caloric expenditure. In a double-blind, randomized, and placebo-controlled trial involving 10 healthy individuals, the p-synephrine isomer was administered at a 50mg serving, both alone, and in combination with hesperidin and naringin. The authors measured resting metabolic rate (RMR), blood pressure, and heart rate, along with subjective feelings of mood and energy, at baseline, and at 45-mintues and 75-minutes after ingestion. The authors reported a significant increase in RMR in each of the supplement groups, relative to placebo.
The combination of caffeine and synephrine appears to potentiate each ingredient’s effects – with rates of fatty acid liberation, heart rate, metabolic rate, and fatty acid oxidation increased in clinical trials featuring the combination. In several studies utilizing other forms of synephrine, it was found that the combination of synephrine and caffeine led to a small but significant reduction in fat mass of 3lbs, and a reduction in bodyfat of 2.9%.
Combined with not only caffeine, but the other ingredients in Castle Bravo, synephrine HCl appears to be a potent weapon in the arsenal for body composition and overall athletic performance.
Huperzia serrata Extract (Leaf and Stem) (std. to 1% Huperzine A)
Huperzia serrata is a compound found in the plant families of Huperziaceae, Lycopodiaceae, and Selaginella and is endemic to China. The Lycopodium alkaloid Huperzine-A, was first isolated from a folk medicinal preparation in 1984.
Due to the potent anticholinesterase activities of Huperzine A, the compound was been evaluated in numerous in vitro, in vivo, and human trials. These data suggest that Huperzine’s Ache activities are most potent in the cortex, hippocampus, and striatum (at least in rats) – key regions in the brain responsible for forming, coordinating, and recalling memory. These effects are assisted by Huperzine A’s high oral bioavailability. Studies using microdialysis technique in rats, for example, showed that the response to Huperzine A was dose-dependent and substantially lowered the level of ACh in cortex.
Huperzine A has also shown promise in humans. Used as a reversible inhibitor of acetylcholinesterase, Huperzine A has shown positive benefits on cognition and as a therapy for individuals suffering from Alzheimer’s Disease. This is partly due to its inhibitory factors on acetylcholine but also its neuroprotective properties. In another study on memory and learning performance, 34 pairs of middle school students complaining of memory inadequacy were given a small dose of Huperzine A. The students were then match paired along several vectors and provided tests on working memory. The results of this study exhibited that Huperzine A markedly improved the memory function of adolescent students.