Clinically Studied Red Spinach
Clinical Studies
The red spinach extract used across Red Spinach Company formulations has been evaluated in human clinical research conducted in collaboration with academic institutions. Its physiological and performance-related effects have been investigated in randomized, double-blind, placebo-controlled crossover trials involving healthy, trained participants.
These studies examined outcomes related to exercise performance, movement efficiency, fatigue, and perceived exertion. The featured research was conducted according to accepted scientific and ethical standards and published in peer-reviewed scientific journals, allowing the methods, findings, and limitations to be reviewed publicly.
The standardized red spinach extract evaluated in these studies is produced by NutriGardens and supplied for use across Red Spinach Company formulations.
Research Institutions & Study Design
Clinical research evaluating red spinach extract has been conducted in collaboration with academic and research institutions. Study designs include randomized, double-blind, placebo-controlled human trials published in peer-reviewed scientific journals.
Select studies were conducted at, or in collaboration with, the following institutions, as reported in the published research:
- Samford University
- University of Alabama at Birmingham
Institutional involvement is described as reported in the published studies and does not imply endorsement of any ingredient or finished product.
Resistance Exercise Study
Participants: 14 resistance-trained men
Design: Randomized, double-blind, placebo-controlled crossover trial
Dose: Approximately 400 mg of naturally occurring dietary nitrate
Study Title
Effects of Acute Red Spinach Powder Ingestion on Muscular Endurance and Resistance Exercise Performance
Summary
This randomized, double-blind, placebo-controlled crossover study evaluated the effects of acute red spinach extract supplementation in resistance-trained men.
Key Findings
- Increased plasma nitrate and nitrite levels compared with placebo
- Higher mean barbell velocity during bench-press exercise
- Lower perceived exertion during resistance training
The results suggest that standardized red spinach extract may support exercise efficiency, barbell movement velocity, and reduced perceived effort during resistance exercise.
Repeated-Sprint Study
Participants: 11 NCAA Division I female soccer athletes
Design: Randomized, double-blind, placebo-controlled crossover trial
Dose: Approximately 400 mg of naturally occurring dietary nitrate
Study Title
Effects of Acute Red Spinach Extract Ingestion on Repeated Sprint Performance in Division I NCAA Female Soccer Athletes
Summary
This randomized, double-blind, placebo-controlled crossover study examined the effects of acute red spinach extract supplementation in NCAA Division I female soccer athletes. The extract was delivered in the finished product formulation used at the time of the study.
Key Findings
- Increased blood nitrate and nitrite concentrations compared with placebo
- Lower fatigue index during repeated sprints
- Improved ability to maintain power across repeated high-intensity efforts
The findings suggest that standardized red spinach extract may support nitric oxide availability and tolerance to repeated high-intensity exercise.
Concentration and Standardization Matter
Human clinical research on dietary nitrate consistently uses defined, measurable nitrate doses to evaluate physiological effects. In supplementation, delivering those doses reliably requires a source that is both concentrated and standardized.
Our red spinach extract is oxalate-free.
Red spinach extract contains the highest naturally occurring concentration of dietary nitrate of any food source, making it a highly concentrated option for delivering clinically relevant nitrate levels in a small, controlled format. Standardization helps reduce variability between servings and supports consistent intake over time.
For these reasons, red spinach extract is well suited for applications where precision, consistency, and practicality are important.
Dietary Nitrate From Other Food Sources
Dietary nitrate itself has been extensively studied in humans, independent of any single food source. A broad body of clinical research has evaluated nitrate intake from a variety of vegetables, helping establish the physiological mechanisms, metabolic pathways, and expected responses associated with nitrate consumption.
The studies below represent human clinical research on dietary nitrate from other food sources. These studies provide broader scientific context for nitrate as a bioactive compound and are not specific to red spinach extract.
Supporting Human Clinical Studies on Dietary Nitrate (Nitric Oxide Pathway)
Dietary Nitrate and Exercise Efficiency
Dietary nitrate supplementation reduces the oxygen cost of submaximal exercise in humans.
🔗 https://pubmed.ncbi.nlm.nih.gov/17635415/
Dietary Nitrate and Exercise Tolerance
Nitrate supplementation may improve exercise tolerance and time to exhaustion in some human studies.
🔗 https://www.frontiersin.org/articles/10.3389/fphys.2019.00404/full
Dietary Nitrate and Blood Pressure
Human trials show dietary nitrate can support healthy blood pressure via nitric oxide–related mechanisms.
🔗 https://pubmed.ncbi.nlm.nih.gov/38403254/
Dietary Nitrate and Vascular Function
Dietary nitrate has been shown to improve vascular function and nitric oxide bioavailability in humans.
🔗 https://pubmed.ncbi.nlm.nih.gov/21454745/
Dietary Nitrate: Exercise Performance Meta-Analysis
Systematic review/meta-analysis evaluating nitrate supplementation and exercise performance outcomes.
🔗 https://pubmed.ncbi.nlm.nih.gov/24791915/
Dietary Nitrate and Endurance Performance
Human research suggests nitrate supplementation may support endurance performance in certain contexts.
🔗 https://pubmed.ncbi.nlm.nih.gov/32560317/
Nitrate–Nitrite–Nitric Oxide Pathway Under Hypoxia
Inorganic nitrate increases nitric oxide availability and influences blood flow under low-oxygen conditions.
🔗 https://pmc.ncbi.nlm.nih.gov/articles/PMC4297773/
Regulatory Notice
The clinical studies referenced on this page evaluate red spinach extract and dietary nitrate as ingredients. These statements have not been evaluated by the Food and Drug Administration. Red spinach extract is not intended to diagnose, treat, cure, or prevent any disease.