Launching a sports nutrition brand today means entering a space crowded with noise. Shelves and websites are filled with products promising extreme energy, massive pumps, and instant results, often backed by long ingredient lists and aggressive stimulation.
RZN Nutrition was built to take a different approach.
We launched with one product because we believed the best way to earn trust was to get one formula right before doing anything else. Core⁵ is the foundation of RZN Nutrition, and this article explains how and why it was built — from ingredient selection and clinical dosing decisions to our decision to prioritize simplicity, transparency, and repeatable performance over excess.
Why We Started With One Product
RZN Nutrition launched with a single pre-workout by design.
Rather than releasing multiple products with overlapping ingredients and inconsistent formulas, we chose to focus on one clear goal: create a pre-workout that supports all essential aspects of performance without unnecessary additives, extreme stimulants, or confusing labels.
By narrowing our scope, we were able to focus on formulation quality, use clinically supported doses, maintain full label transparency, and build a product that can be used consistently — not occasionally.
Core⁵ is not designed to overwhelm. It is designed to work, session after session.
The Philosophy Behind Core⁵
The sports nutrition industry often equates effectiveness with complexity. More ingredients, higher stimulant doses, and louder claims are assumed to mean better performance.
The evidence does not support that assumption.
Performance is driven by a small number of well-studied physiological mechanisms: energy production and strength output, blood flow and nutrient delivery, fatigue buffering during high-intensity work, mental focus and alertness, and hydration with proper neuromuscular function.
Core⁵ was built to support these mechanisms directly, using ingredients that are extensively researched and consistently effective when dosed correctly. The goal was not to create a product that feels intense once, but one that performs reliably across regular training.
Core⁵ is built for people who train consistently, value repeatable performance, and want to know exactly what they’re putting into their body. It’s designed for those who want results without excess — and consistency without compromise.
Ingredient Selection and Clinical Dosing Rationale
Every ingredient in Core⁵ was selected intentionally and dosed based on established clinical research. The goal was not to include as many ingredients as possible, but to use the few that consistently support performance — at amounts shown to work.
Creatine Monohydrate – 5,000 mg
Creatine monohydrate supports rapid ATP regeneration, allowing muscles to sustain repeated high-power output during resistance training and high-intensity exercise. It is one of the most extensively researched supplements in sports nutrition and is consistently associated with improvements in strength, power, and training volume.
The International Society of Sports Nutrition states that daily intake of 3–5 grams of creatine monohydrate is sufficient to fully saturate muscle creatine stores and maximize performance benefits for most individuals¹. Core⁵ includes 5,000 mg, placing it at the upper end of the clinically supported range and eliminating the need for loading phases or additional supplementation.
L-Citrulline Malate (2:1) – 6,000 mg
L-Citrulline Malate (2:1) increases arginine availability more effectively than arginine itself, supporting nitric oxide production and improved blood flow during training. The malate component contributes to energy metabolism, supporting endurance and sustained output.
Systematic reviews and controlled trials consistently show performance benefits when citrulline malate is dosed at 6–8 grams, particularly for resistance training volume and endurance performance². Core⁵ includes 6,000 mg, placing it directly within the clinically effective range supported by the literature.
Beta-Alanine – 3,500 mg
Beta-alanine increases muscle carnosine concentrations, which buffer hydrogen ion accumulation during high-intensity exercise. This buffering effect delays fatigue during repeated efforts such as high-rep sets or short rest periods.
Meta-analyses demonstrate that performance benefits occur when beta-alanine intake reaches approximately 3.2–6.4 grams per day, accumulated over time³. Core⁵ includes 3,500 mg, exceeding the minimum effective daily dose shown to improve high-intensity exercise capacity while supporting consistent, long-term use.
Caffeine – 200 mg
Caffeine enhances alertness, focus, reaction time, and perceived effort through central nervous system stimulation. It is one of the most reliable ergogenic aids across both resistance and endurance training.
Research shows that caffeine improves performance across a broad intake range; however, the majority of performance benefits are achieved at moderate doses, while higher intakes primarily increase the likelihood of side effects rather than results⁴⁵. Reviews indicate that once intake exceeds roughly 3–6 mg per kilogram of body weight, additional performance benefits diminish while negative effects become more likely.
Core⁵ includes 200 mg of caffeine, a moderate dose chosen to support clean energy and focus while prioritizing repeatable performance and recovery. This dose also aligns well with the FDA’s general guidance of up to 400 mg per day for healthy adults⁷, allowing flexibility for real-world caffeine intake — including coffee or, when appropriate, a second serving — without forcing users toward excessive stimulation.
Electrolyte Complex – 857 mg Total
(Sodium, Potassium, Magnesium, and Chloride)
Electrolytes were included in Core⁵ to support hydration, neuromuscular signaling, and muscular contraction — all of which directly impact performance during training.
During a 60-minute high-intensity workout, athletes can lose approximately 300–1,000 mg of sodium, depending on sweat rate, environment, and exercise intensity⁶. Even moderate electrolyte losses can impair fluid balance, muscle contraction, and endurance output if not addressed.
Rather than attempting to fully replace sweat losses in a pre-workout, Core⁵ provides a strategic electrolyte baseline designed to support hydration and neuromuscular function without overwhelming the formula or competing with fluid intake during training.
Core⁵ includes:
- Sodium (240 mg) to support plasma volume, nerve signaling, and muscle contraction
- Potassium (200 mg) to support intracellular hydration and muscle function
- Magnesium (60 mg) to support energy metabolism and neuromuscular signaling
- Chloride (~357 mg) to support fluid balance and osmotic regulation
Together, these electrolytes total 857 mg, an amount aligned with exercise hydration research and designed to support performance during typical training sessions without unnecessary excess⁶. This approach complements in-workout hydration strategies rather than attempting to replace fluids entirely.
Why We Chose Five Ingredients
Core⁵ contains five core ingredients because those ingredients, when dosed correctly, cover the essential performance needs of a complete workout.
Adding more compounds does not automatically improve results and often leads to underdosing, redundancy, or unnecessary complexity.
Why We Launched With One Flavor
Core⁵ launched with a single flavor — Strawberry Lemonade — intentionally.
Starting with one flavor allowed us to focus on formula integrity, mixability, taste balance, and manufacturing consistency. Additional flavors are planned as RZN Nutrition grows, while the formula itself will remain unchanged.
What’s Next for RZN Nutrition
Core⁵ is the foundation of RZN Nutrition.
Future plans include additional flavors, a non-stimulant option, and expanded performance-focused products — all built to the same standard of clarity, effectiveness, and consistency.
Closing Thoughts
Core⁵ was built intentionally.
It reflects a belief that sports nutrition should be simple, effective, and easy to trust. Rather than chasing extremes, RZN Nutrition focuses on clarity, consistency, and repeatable performance.
Core⁵ is the first step — and the standard for everything that follows.
References
- Kreider RB, et al. (2017). International Society of Sports Nutrition position stand: Safety and efficacy of creatine supplementation. Journal of the International Society of Sports Nutrition, 14:18.
- Gonzalez AM, et al. (2019). Effects of citrulline supplementation on exercise performance. Journal of Strength and Conditioning Research, 33(7), 1994–2005.
- Hobson RM, et al. (2012). Effects of beta-alanine supplementation on exercise performance. Amino Acids, 43(1), 25–37.
- Grgic J, et al. (2020). Effects of caffeine intake on muscle strength and power. British Journal of Sports Medicine, 54(11), 681–688.
- Spriet LL. (2014). Exercise and sport performance with low doses of caffeine. Sports Medicine, 44(S2), 175–184.
- Sawka MN, et al. (2007). ACSM position stand: Exercise and fluid replacement. Medicine & Science in Sports & Exercise, 39(2), 377–390.
- U.S. Food & Drug Administration. Spilling the Beans: How Much Caffeine Is Too Much?
† These statements have not been evaluated by the Food and Drug Administration. This article is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary.
