Setria For Sport by Kyowa Hakko: The Science Behind Glutathione + Citrulline for Athletic Excellence

New research on Setria® For Sport shows combining 200mg Setria® Glutathione with 2g L-Citrulline creates powerful synergy for nitric oxide production. Studies demonstrate increased lean mass and enhanced blood flow beyond either ingredient alone.

In the ever-evolving world of sports nutrition, athletes and fitness enthusiasts are constantly seeking scientifically-backed ingredients that can safely enhance their recovery and overall results. While single-ingredient solutions have their place, many exciting advancements also come from synergistic combinations that create effects greater than the sum of their parts.

Enter Setria For Sport — Kyowa Hakko’s innovative pairing of 200mg Setria® Glutathione with at least 2g L-Citrulline that’s putting a new spin on sports nutrition.

Setria For Sport: Helping Nitric Oxide Last Longer

Setria® L-Glutathione isn’t just any glutathione ingredient, it’s a clinically-researched form of L-glutathione manufactured to exceptionally high standards by Kyowa Hakko Bio Co., Ltd. As the body’s most powerful endogenous antioxidant, glutathione plays critical roles in detoxification, immune function, and cellular protection. But when combined with L-citrulline, an amino acid that serves as a precursor to nitric oxide (NO) by way of L-arginine, something remarkable happens: enhanced nitric oxide production and signaling that can benefit athletes across multiple metrics.

Setria For Sport stands out due to the powerful synergy between these two ingredients. While individually beneficial, research has shown that the combination creates enhanced effects on blood flow / vasodilation, nitric oxide production, and body composition better than either ingredient can achieve alone.^[1] This powerful duo represents a safe, science-backed approach to supplementation that addresses multiple aspects of athleticism.

Glutathione is one of the most powerful antioxidants in the body.

In this guide, we’ll explore the science behind Setria For Sport, the individual roles of glutathione and L-citrulline, and how their combination creates unique benefits for athletes and active individuals. We’ll examine the research that supports these benefits and provide practical recommendations to incorporate the combination into your supplementation stack or next product formula.

Don’t miss any updates on Setria and other Kyowa Hakko innovations! Sign up for PricePlow’s Kyowa Hakko news alerts to stay informed about new research, products, and developments in the world of sports and active nutrition.

Before getting into the combination, it’s best to start with a background on glutathione itself:

Setria®: The Science of Glutathione

Glutathione (GSH) stands as the body’s most abundant endogenous antioxidant, earning its reputation as the “master antioxidant” through its critical role in maintaining cellular health. This powerful tripeptide consists of three amino acids: glutamic acid, cysteine, and glycine. While the body naturally produces glutathione, various factors like aging, stress, poor nutrition, and intense exercise can deplete its levels, making supplementation potentially beneficial for many individuals.

• How Glutathione Functions

  GSH operates through several key mechanisms that make it indispensable for optimal health and wellness:

  Table of Contents

  Toggle
  1. Powerful Antioxidant Defense – Glutathione directly neutralizes free radicals and reactive oxygen species (ROS) that cause oxidative stress, protecting cells from damage during intense exercise.^[2]
  2. Regeneration of Other Antioxidants – Glutathione helps recycle other important antioxidants like vitamins C and E, maximizing the body’s overall antioxidant capacity.
  3. Detoxification Support – The liver uses glutathione to bind to and remove toxins, heavy metals, and other harmful compounds from the body, a process athletes benefit from when expelling exercise-induced metabolic waste products.
  4. Cellular Defense and Repair – Glutathione maintains the integrity of cellular components, including proteins and lipids, while supporting DNA synthesis and repair.
  5. Immune Function Enhancement – Glutathione plays a crucial role in proper immune function, including T-cell proliferation and natural killer cell activity.^[2]

• Benefits of Optimal Glutathione Levels

  Maintaining optimal glutathione levels offers numerous advantages for active individuals:

  • Enhanced Recovery – By combating oxidative stress caused by intense exercise, glutathione may help minimize muscle damage and accelerate recovery between training sessions.
  • Improved Immune Function – Athletes with higher glutathione levels may experience fewer training interruptions due to illness, as GSH supports natural killer cell activity and proper immune response.
  • Promote Healthy Inflammation Levels – Glutathione has been shown to regulate inflammatory responses,^[2,3] potentially reducing exercise-induced inflammation.
  • Support for Nitric Oxide Function – Critical for athletes, glutathione helps stabilize nitric oxide, enhancing its beneficial effects on blood flow and oxygen delivery to working muscles.^[1]
  • Cellular Energy Production – Glutathione protects mitochondria (the cell’s power plants) from oxidative damage, potentially supporting more efficient energy production during exercise.
  

  Clinical research demonstrates Setria® delivers impressive increases in glutathione levels across multiple body tissues, doubles natural killer cell activity, and requires consistent supplementation for maintained benefits. A truly evidence-based ingredient choice.^[2]

  Research demonstrates that glutathione supplementation can effectively increase body stores of this vital antioxidant. A six-month randomized controlled trial showed that daily consumption of glutathione supplements increased GSH levels by 30-35% in erythrocytes, plasma, and lymphocytes; and 360% in buccal cells compared to baseline in blood, erythrocytes, plasma.^[2] This confirms that oral supplementation with a quality L-glutathione supplement, such as Setria®, provides a viable method for enhancing the body’s glutathione status.

L-Citrulline: The Perfect Partner

L-Citrulline is a non-essential amino acid named after citrullus, the Latin word for watermelon, where it was first discovered in high concentrations. Though the body can produce L-citrulline naturally, supplementation provides additional benefits, especially for athletes and active individuals seeking to enhance their results.

• The Nitric Oxide Pathway

  L-Citrulline works through the following pathway:^[4]

  1. When consumed, L-citrulline bypasses the liver’s first-pass metabolism and enters the bloodstream efficiently.
  2. It then travels to the kidneys, where it converts to L-arginine, the direct precursor to nitric oxide (NO).
  3. This conversion creates a recycling pathway known as the citrulline-NO cycle, where NOS (nitric oxide synthase) enzymes transform L-arginine into NO and L-citrulline.

  This cycle continues with the newly formed L-citrulline converting back to L-arginine, creating a sustainable supply of NO precursors.

  Nitric oxide serves as a potent vasodilator that relaxes blood vessels, enhancing blood flow and oxygen delivery to muscle tissues. This process proves essential for overall exercise results, recovery, and overall cardiovascular health.

• Why L-Citrulline Supplementation Outperforms L-Arginine

  

  This tripeptide powerhouse represents your body’s primary defense against oxidative stress and toxins. While naturally produced, glutathione levels decline with age, poor diet, and environmental stressors, making supplementation increasingly valuable.

  Despite L-arginine’s direct role in NO production, L-citrulline offers several advantages as a supplement:

  1. Superior Bioavailability – Oral L-arginine undergoes extensive breakdown in the intestines and liver, with approximately 40% degraded during first-pass metabolism. L-citrulline avoids this fate, reaching the bloodstream intact.^[5]
  2. More Effective at Raising Arginine Levels – Studies show that L-citrulline supplementation increases plasma L-arginine concentrations more effectively than an equivalent dose of L-arginine itself.^[5]
  3. Sustained NO Production – L-citrulline creates a longer-lasting elevation of plasma arginine levels compared to direct L-arginine supplementation, providing extended NO production benefits.
  4. Arginase Bypass – L-citrulline isn’t affected by the enzyme arginase, which breaks down L-arginine in the gut and liver. This allows more efficient conversion to NO where it matters most — in the blood vessels and muscle tissue.
  5. Better Performance Benefits – Research demonstrates that L-citrulline supplementation improves oxygen uptake kinetics and high-intensity exercise performance in ways that L-arginine supplementation does not.^[4]

  These advantages make L-citrulline an ideal component in the Setria For Sport formula, working alongside glutathione to maximize nitric oxide production and stability.

Setria For Sport: The Ultimate Combination

The marriage of L-citrulline and glutathione repeatedly creates a positive effect in the clinical research. This combination works through complementary pathways that enhance nitric oxide (NO) production, bioavailability, and stability — delivering benefits that exceed simple addition of their individual effects.

• Complementary Mechanisms

  When combined, these compounds create a multi-faceted approach to NO enhancement:

  

  Combining Setria® Glutathione with L-Citrulline delivers significantly higher nitrate concentrations than either ingredient alone or placebo. This translates to enhanced blood flow, nutrient delivery, and potential endpoint improvements for athletes.^[1]

  1. Increased Substrate Availability – As described above, L-citrulline effectively raises plasma L-arginine levels, providing more raw material for nitric oxide synthase (NOS) enzymes to produce NO.
  2. Enhanced NO Stability – Once NO is produced, glutathione acts as a powerful protector against oxidative damage. GSH forms S-nitrosoglutathione (GSNO), which serves as a stable NO carrier and reservoir in the body.^[6]
  3. Amplified NOS Activity – Glutathione stimulates total L-arginine turnover and increases NOS activity, resulting in greater NO production from available L-arginine.^[1]
  4. Reduced NO Degradation – Glutathione’s potent antioxidant capabilities neutralize reactive oxygen species that would otherwise degrade NO, extending its half-life and biological activity.

• The Biochemical Advantage

  The power of this combination lies in addressing multiple limiting factors in NO production simultaneously:

  • L-citrulline elevates plasma arginine in a way that direct arginine supplementation cannot, creating a sustained supply of NO precursors.
  • Glutathione upregulates the NOS pathway and protects NO from oxidative reaction.
  • Together, they create a continuous cycle of NO production and protection, maintaining higher levels of bioavailable NO for longer periods.
  

  Images courtesy Kyowa Hakko, the sponsor of this article

  This relationship helps explain why the specific combination of 200mg of Setria® Glutathione with 2g of L-citrulline found in Setria For Sport shows such promising effects in clinical research. The combination addresses both the production and preservation of nitric oxide, making for a dual-action approach that provides benefits ranging from enhanced blood flow, increased lean muscle mass relationship with strength gains and cardiovascular support.

Rather than just adding two beneficial ingredients together, Setria For Sport leverages their biochemical synergy to create a compound effect, where 1 + 1 = 3 in terms of physiological impact.

Now let’s see the research on these two together:

Research-Backed Benefits

The combination of L-citrulline and glutathione found in Setria For Sport has been investigated in multiple clinical studies, each revealing distinct benefits for different populations. Let’s examine the research supporting this powerful combination and the specific advantages it offers athletes and active individuals.

• McKinley-Barnard et al. (2015): Establishing the Foundation

  The groundbreaking 2015 study by McKinley-Barnard and colleagues first demonstrated the synergistic effects of combining L-citrulline and glutathione on nitric oxide biomarkers. Researchers conducted a randomized, double-blind, placebo-controlled trial comparing the effects of placebo, L-citrulline (2g), glutathione (1g), and the combination of L-citrulline (2g) with glutathione (200mg).^[1]

  

  While placebo and single ingredients show declining nitric oxide levels post-exercise, the Setria® and L-Citrulline combination maintains elevated NO production well after your workout ends. This synergy explains why serious athletes are turning to this powerful pairing.^[1]

  The results were exciting:^[1]

  • While L-citrulline alone increased plasma arginine, the combination with glutathione was most effective at increasing plasma nitrite and nitric oxide metabolites (NOx).
  • The combined supplementation significantly increased plasma nitrite and NOx concentrations 30 minutes after exercise, while neither supplement alone achieved this effect.
  • The research team concluded that “combining L-citrulline with GSH augments increases in nitrite and NOx levels during in vitro and in vivo conditions.”

  This study established the scientific foundation for the Setria For Sport combination, proving that the two ingredients work synergistically to boost nitric oxide production beyond what either can achieve individually.

• Hwang et al. (2018): Lean Mass and Muscular Strength Support

  Building on the initial findings, Hwang and colleagues conducted an 8-week study examining how the L-citrulline + glutathione combination affects body composition and strength when paired with resistance training. Their randomized, double-blind, placebo-controlled trial involved 75 resistance-trained males divided into three groups: placebo, L-citrulline malate, or L-citrulline (2g) + glutathione (200mg).^[6]

  Key findings included:^[6]

  

  The combination of glutathione and citrulline significantly increased lean muscle after just 4 weeks of resistance training, outperforming both placebo and citrulline malate alone.^[6]

  • The L-citrulline + glutathione group experienced significant increases in lean mass compared to placebo after 4 weeks of resistance training.
  • A significant correlation between lean mass and muscle strength was observed only in the L-citrulline + glutathione group, suggesting this combination uniquely supports the relationship between muscle growth and functional strength.
  • No adverse effects were reported, confirming the safety profile of this combination for daily use.

  This study demonstrated the practical application of the Setria For Sport formula for resistance training athletes seeking improvements in body composition and strength.

• Figueroa et al. (2023): Cardiovascular Health Benefits

  A 2023 study by Figueroa and colleagues examined the combination’s effects on vascular function and blood pressure in postmenopausal women. This randomized, controlled trial compared the effects of L-citrulline (6g), combined L-citrulline (2g) + glutathione (200mg), and placebo over 4 weeks.^[7]

  

  Flow-mediated dilation, a marker of blood vessel health, improved significantly with glutathione plus citrulline supplementation but not with citrulline alone or placebo.^[7]

  The study revealed important cardiovascular benefits:^[7]

  • The L-citrulline + glutathione combination significantly improved flow-mediated dilation (FMD), a measure of endothelial function and vascular health.
  • Blood pressure reactivity to stress (cold pressor test) was significantly attenuated in the combination group compared to both placebo and L-citrulline alone.
  • The researchers concluded that “This study showed that CIT+GSH improved FMD and attenuated systolic BP and MAP (mean arterial pressure) reactivity in PMW (postmenopausal women).”

  These findings highlight the combination’s potential benefits for cardiovascular health and stress response, extending its applications beyond purely athletic achievement.

• Cabre et al. (2023): Endurance Enhancement

  The most recent study by Cabre et al. examined how L-citrulline + glutathione positively affects blood flow during endurance activities in trained males. This randomized, double-blind, placebo-controlled crossover study compared placebo against L-citrulline (2g) + glutathione (200mg).^[8]

  Their findings reveal important benefits for endurance athletes:^[8]

  

  Muscle tissue maintained higher oxygen levels throughout severe-intensity exercise with citrulline supplementation. This improved oxygenation supports the ingredient’s vasodilation and blood flow benefits.^[4]

  • Blood flow was significantly augmented 30 minutes post-exercise in the L-citrulline + glutathione group compared to placebo.
  • Plasma concentrations of L-citrulline and L-arginine were significantly elevated immediately post-exercise and 30 minutes post-exercise following supplementation.
  • Tissue oxygenation index was significantly improved during exercise in the combination group.
  • The researchers noted that “acute ingestion of SPB [Setria Performance Blend]* after eight days may enhance blood flow, L-citrulline, and L-arginine plasma concentrations after high-intensity exercise, which may enhance performance.”

    *Setria Performance Blend is now referred to as Setria for Sport

  This study demonstrates the specific benefits for endurance athletes, especially in terms of improved blood flow, oxygen delivery, and recovery capacity following high-intensity exercise.

Collectively, these four studies build a comprehensive picture of how the unique combination of L-citrulline and glutathione in Setria For Sport benefits nitric oxide production, blood flow, and vascular health, even showing improvements in body composition. The research consistently shows advantages over either ingredient alone or placebo.

Additionally, prior research has connected nitric oxide and blood flow improvements to performance and recovery, which we hope to see tested directly in future Setria for Sport research.

Athletic Applications

The research-backed benefits of Setria For Sport translate into specific applications for various types of athletes. Understanding how and when to use the combination can help maximize its effectiveness for your training goals.

The glutathione-citrulline combination blunted blood pressure spikes during cold stress testing, supporting better cardiovascular adaptation compared to citrulline alone or placebo.^[7]

• For Endurance Athletes

  Endurance athletes can benefit from the improved oxygen kinetics and enhanced blood flow that Setria For Sport provides. Cyclists, runners, swimmers, and triathletes may experience:

  • Faster oxygen uptake during high-intensity efforts
  • Improved tissue oxygenation during prolonged exercise
  • Enhanced blood flow for better nutrient delivery and waste removal
  • Reduced cardiovascular stress response during intense training

  For optimal results, endurance athletes should supplement daily, taking Setria For Sport approximately 60-90 minutes before training sessions.

• For Strength and Power Athletes

  Strength athletes, bodybuilders, and power-focused competitors can leverage Setria For Sport for:

  • Increased lean mass development when combined with resistance training
  • Enhanced muscle pump and nutrient delivery to working muscles
  • Improved recovery between intense sets
  • Better strength-to-muscle mass correlation

  Strength athletes should consider daily supplementation with pre-workout doses timed 60 minutes before training sessions.

• Potential Recovery Applications

  

  Oral glutathione supplementation significantly enhanced natural killer cell activity and supported lymphocyte proliferation after three months. These improvements in immune function demonstrate benefits beyond basic antioxidant protection.^[2]

  Beyond athletics, Setria For Sport offers nitric oxide production enhancement, and increases in NO production may offer both performance enhancement and valuable recovery benefits. This could possibly lead to:

  • Enhanced blood flow for faster clearance of metabolic waste products
  • Reduced oxidative stress from intense exercise
  • Support for immune function during heavy training periods
  • Improved vascular response to exercise-induced stress

  For recovery-focused applications, consider taking Setria For Sport immediately after training or before bed to support overnight recovery processes.

• Recommended Protocol

  For most athletes, a daily protocol works best:

  • Daily dose: 200mg Setria® Glutathione + 2g L-citrulline
  • Timing: 60-90 minutes before exercise on training days
  • Consistency: Maintain daily supplementation even on rest days to keep nitric oxide production optimized
  • Duration: Studies show benefits beginning within days, with optimal results after 4-8 weeks of consistent use

Safety Considerations

One of the standout features of Setria For Sport is an excellent safety profile, making it appropriate for consistent use as part of a long-term supplementation strategy.

Oral glutathione at 1000mg daily significantly boosted GSH concentrations in plasma, lymphocytes, and particularly buccal cells, where levels jumped over 260% from baseline. The washout period demonstrates supplementation must be ongoing for sustained benefits.^[2]

• Safety Endpoints in Research

  Multiple clinical studies have confirmed the safety of both L-citrulline and glutathione, with no significant adverse effects reported when used as directed:

  • Hwang et al. found “no adverse effects on blood clinical safety markers” in their 8-week study with resistance-trained males.^[6]
  • A long six-month trial of oral glutathione by Richie et al. showed “GSH was highly tolerated and its administration was not associated with any signs of adverse effects.”^[2]
  • Blood chemistry markers, including liver and kidney function tests, remain unaffected even with extended use.

  These findings confirm that Setria For Sport can be safely incorporated into daily supplementation routines without concerns about adverse reactions.

• Recommended Dosing

  The clinically effective dose shown in research is:

  • 200mg of Setria® Glutathione
  • 2g of L-citrulline

  This specific ratio has been tested in multiple studies. However, many supplements, including the two below, utilize more citrulline, as is commonplace in the pre-workout category.

Setria For Sport Products to Try

Many products contain Setria® Glutathione, and we’ve covered a couple of pre-workout supplements on the PricePlow Blog that use it with L-citruline:

• Ghost Pump

  

  Read more about Ghost Pump on the PricePlow Blog

  Ghost Pump delivers a stimulant-free pre-workout experience built around 6 grams of L-citrulline paired with 200mg of Setria® L-glutathione in its V2 formulation. This powerful pump formula packs 3 grams of arginine nitrate (NO3-T) to further amplify blood flow benefits, creating a multi-pathway approach to vasodilation.

  Ghost’s strategic V2 included PureWay-C (vitamin C) to synergize with Setria, and pine bark extract (95% proanthocyanidins) for more blood flow support. The formula also features 2 grams of taurine and AstraGin for improved ingredient absorption. Ghost Pump can be used as a standalone pre-workout for stimulant-free training or effectively stacked with Ghost Legend for a complete pre-workout experience.

  GHOST Pump – Deals and Price Drop Alerts

  Get Price Alerts

  Get Pump Price AlertsGet GHOST alertsGet Stimulant-Free Pre Workout Supplements price drops

  Also get hot deal alerts

  No spam, no scams.

  Disclosure: PricePlow relies on pricing from stores with which we have a business relationship. We work hard to keep pricing current, but you may find a better offer.

  Posts are sponsored in part by the retailers and/or brands listed on this page.

• ZOA+ Pre-Workout

  

  ZOA+ Pre-Workout is Dwayne “The Rock” Johnson’s premium performance formula featuring 4 grams of L-citrulline with 200mg of Setria® L-glutathione. This NSF Certified for Sport supplement ensures athletes can train with confidence, knowing they’re using a product free from banned substances.

  ZOA+ delivers comprehensive performance support with clinical doses of beta-alanine (3.2g), betaine anhydrous (1.25g), and CON-CRĒT Creatine HCl (1g). The formula is rounded out with 200mg of natural caffeine, L-tyrosine (800mg), Alpha-GPC (200mg from 400mg of 50%), and supporting ingredients like ginkgo biloba and guayusa extract. The product also includes a complete B-vitamin complex and electrolytes from sodium and potassium citrate, making it a well-rounded pre-workout option.

  ZOA + Maximum Performance Pre-Workout – Deals and Price Drop Alerts

  Get Price Alerts

  Get + Maximum Performance Pre-Workout Price AlertsGet ZOA alertsGet Pre Workout Supplements price drops

  Also get hot deal alerts

  No spam, no scams.

  Disclosure: PricePlow relies on pricing from stores with which we have a business relationship. We work hard to keep pricing current, but you may find a better offer.

  Posts are sponsored in part by the retailers and/or brands listed on this page.

Conclusion: Setria for Sport Brings Significant Synergy

The combination of Setria® Glutathione and L-citrulline is a safe and efficacious advancement in sports nutrition supplementation. This innovative pairing creates synergistic effects that enhance nitric oxide production and stability beyond what either ingredient can achieve alone.

Katie Emerson and Tony Miano of Kyowa Hakko join PricePlow to discuss the latest Cognizin and Setria research developments at Expo West 2025 in Episode #163.

The research-backed benefits of Setria For Sport include:

• Setria® glutathione plays a role in supporting nitric oxide function
• Setria® in combination with citrulline helps sustain nitric oxide levels for a longer-lasting effect
• Setria® in combination with citrulline aids in vasodilation to fuel muscles
• Setria® in combination with citrulline supports NO levels 30-minute post-exercise compared to citrulline alone
• Setria® in combination with citrulline supports lean body mass as part of resistance training
• Setria® in combination with citrulline supports cardiovascular health

These benefits stem from the complementary mechanisms through which glutathione and L-citrulline work together: L-citrulline increases the substrate for NO production while glutathione protects and extends NO bioavailability.

Meanwhile, the versatility of Setria For Sport makes it appropriate for nearly any active individual, regardless of training style or performance goals. Whether you’re a strength athlete, endurance competitor, or simply an active adult, the Setria + citrulline combination can provide benefits.

Don’t Miss Our Podcast from Expo West 2025

Cognizin® Citicoline is dubbed the The Brain Choline not just because it provides choline, but because it also supplies cytidine, which is also needed for the synthesis of phosphatidylcholine

For a deeper dive into the ongoing research on Setria For Sport, we recommend checking out our recent podcast interview with Katie Emerson and Tony Miano from Kyowa Hakko, recorded at Expo West. Katie, Senior Manager of Scientific Affairs at Kyowa Hakko, discusses the latest studies examining this powerful combination, including newly discovered mechanisms and applications in sports nutrition.

Just like we’ve seen with Cognizin® citicoline, Setria For Sport stands as a testament to Kyowa Hakko’s commitment to research-backed innovation, addressing multiple physiological pathways.

If you’re looking to enhance your blood flow and nitric oxide production during training, these benefits may lead to better performance, support your recovery, or optimize your body composition. Setria For Sport offers a scientifically validated solution backed by multiple clinical studies and Kyowa Hakko’s renowned quality standards.