Legal peptides have entered endurance sports, promising enhanced recovery and bulletproof joints. What are legal peptides? What do they do for us? Here’s what the research says.
Safe for Competition
Competitive athletes need to know that certain peptides are entirely legal and explicitly permitted by the World Anti-Doping Agency (WADA). Unlike synthetic peptides banned in sports, legal peptides fall into specific categories that don’t violate anti-doping regulations.
For collagen peptides, the United States Anti-Doping Agency (USADA) explicitly states that collagen peptides are not prohibited, clarifying that they are not the same as banned “peptide hormones.”¹
Plant-based peptides, like PeptiStrong® and PeptiSleep™, are not specifically banned by WADA, as they don’t fall into prohibited categories such as growth hormone-releasing peptides or synthetic anabolic agents.
Both SwissRX Synthesis and SwissRX Dream are NSF Certified for Sport®, providing additional assurance for competitive athletes.
Collagen Peptides: The Structural Foundation
Collagen is your body’s internal scaffolding, making up roughly 25-30% of all protein and creating the structural foundation of your skin, bones, muscles, tendons, ligaments and cartilage.
Collagen peptides are collagen broken down into smaller, more easily absorbed pieces through a process called hydrolysis. While intact collagen molecules are too large to be absorbed effectively, these smaller peptide chains can pass through your digestive system and reach target tissues.
Unlike synthetic peptides designed in laboratories, collagen peptides are derived from natural animal sources – typically bovine hide, marine sources or other connective tissues.
The Cellular Signaling Process
When you consume collagen peptides, your body doesn’t rebuild them into new collagen. Instead, these peptides function as messengers, telling your cells to boost collagen production in specific areas.
Studies show that collagen-derived peptides can stimulate fibroblasts – the cells responsible for producing collagen – to increase their activity. Research indicates that bioactive peptides can boost new collagen synthesis, especially in connective tissues that endurance athletes stress repeatedly during training.
Applications for Endurance Athletes
Endurance athletes use collagen peptides primarily for joint health and injury prevention. The repetitive stress of cycling, running and swimming constantly hammers connective tissues, making structural support valuable.
Several studies have investigated collagen peptides in athletic populations. Research published in the British Journal of Sports Medicine found that athletes supplementing with collagen peptides showed improvements in joint comfort during activity.²
Another study in the American Journal of Clinical Nutrition demonstrated that collagen peptide supplementation could enhance the body’s natural collagen synthesis response when combined with exercise.³
Emerging research suggests that regular supplementation may help maintain joint function during periods of high training volume.
Plant-Based Peptides
Beyond collagen, innovative plant-derived peptides offer targeted benefits through AI-discovered formulations.
PeptiStrong®: The Natural Muscle Builder
PeptiStrong® represents a breakthrough in plant-based performance nutrition. Derived from fava bean, this network of cell signaling peptides offers five clinical benefits in one 2.4 g dose – increased muscle protein synthesis, reduced muscle breakdown, decreased exercise-induced inflammation, lowered myostatin levels (inhibits muscle development) and enhanced energy production.
Clinical studies have demonstrated improvements in power output of up to 144% and performance increases of up to 54% in trained individuals.⁴ For endurance athletes, PeptiStrong® offers faster recovery between workouts, reduced muscle soreness and the ability to train more frequently without overreaching.
SwissRX Synthesis, containing PeptiStrong®, is NSF Certified for Sport®, providing competitive athletes with confidence in its safety and compliance.
PeptiSleep™: Natural Sleep Optimization
PeptiSleep™, derived from rice bran protein, represents the world’s first AI-discovered plant-based peptide designed to enhance all stages of sleep.
Unlike traditional sleep aids that cause morning grogginess, PeptiSleep™ works by reducing cortisol – the hormone responsible for stress and poor sleep. With a 250 mg dose taken 30 minutes before bed, athletes can experience improved sleep onset, enhanced deep and REM sleep time and better sleep biometrics.
Clinical studies using smart rings showed that 61% of participants fell asleep faster, with increases of 17% in deep sleep, 13% in light sleep and an average of 35 additional minutes of total sleep.⁵ Heart rate variability improved by 32%, indicating better recovery and adaptation.
SwissRX Dream, containing PeptiSleep™, is NSF Certified for Sport®, ensuring competitive athletes can trust its purity and compliance.
PeptiSleep™ is also included in our favorite nighttime tonic, Dream Shot, alongside tart cherry and other sleep-enhancing ingredients.
Optimizing Intake and Timing
Collagen Peptides – Take 30-60 minutes before exercise for optimal tissue repair and adaptation. Vitamin C enhances collagen synthesis, so pairing intake with vitamin C-rich foods may boost effectiveness. Most research showing benefits used 10-20 grams daily.⁶
Plant-Based Peptides: PeptiStrong® in SwissRX Synthesis yields optimal results around training sessions, with the 2.4 g dose providing sustained benefits. PeptiSleep™ in SwissRX Dream works best when taken 30 minutes before bedtime.
Managing Expectations
Research on legal peptides continues showing promising results for athletes. Studies have demonstrated benefits across different time periods, with many showing positive effects within 4-8 weeks of consistent use.
Research shows that peptides work best as part of a comprehensive approach to performance optimization, complementing proper training, nutrition and recovery practices.
Conclusions for Endurance Athletes
Legal peptides are scientifically backed methods to enhance endurance performance.
From collagen peptides supporting connective tissue health to plant-based peptides optimizing muscle function and sleep quality, these compounds offer targeted solutions for the demands of endurance training.
The combination of regulatory compliance, research support and minimal side effects makes legal peptides a low-risk addition to an endurance athlete’s nutrition strategy when combined with proper training, nutrition and recovery practices.
As research continues to evolve, these compounds represent a promising, athlete-safe option in the expanding menu of evidence-based sports nutrition.
References:
USADA. (2024). What Athletes Need to Know about Collagen. Retrieved from https://www.usada.org/spirit-of-sport/athlete-need-know-collagen/
Zdzieblik, D., et al. (2015). Collagen peptide supplementation in combination with resistance training improves body composition and increases muscle strength in elderly sarcopenic men. British Journal of Nutrition, 114(8), 1237-1245.
Shaw, G., et al. (2017). Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis. The American Journal of Clinical Nutrition, 105(1), 136-143.
Kerr, A., et al. (2023). Improved Strength Recovery and Reduced Fatigue with Suppressed Plasma Myostatin Following Supplementation of a Vicia faba Hydrolysate, in a Healthy Male Population. Nutrients, 15(4), 986.
Nuritas Internal Clinical Study. (2025). PeptiSleep™ Sleep Quality and Biometric Improvements Using Smart Ring Technology.
Clark, K. L., et al. (2008). 24-Week study on the use of collagen hydrolysate as a dietary supplement in athletes with activity-related joint pain. Current Medical Research and Opinion, 24(5), 1485-1496.
