Doctor's Best Fast Acting Arginine Complex with Nitrosigine® 60 Tablets provides a patented, clinically studied arginine silicon complex (inositol-stabilised arginine silicate) that generates nitric oxide significantly faster than standard L-Arginine. Nitrosigine® is shown to increase plasma arginine levels within 15 minutes and sustain nitric oxide production for cardiovascular, cognitive, and performance benefits.*

• Nitrosigine® — patented fast-acting arginine silicon complex*
• Increases plasma arginine within 15 minutes of ingestion*
• Sustained nitric oxide support for cardiovascular health*
• Supports blood flow, focus, and exercise performance*
• Backed by multiple human clinical trials*
• Non-GMO | Gluten Free | 60 tablets

Suggested Use: As a dietary supplement, take 1 tablet daily, preferably before exercise.

Frequently Asked Questions

What is Nitrosigine and how does it differ from regular L-Arginine?

Nitrosigine® is a patented complex of inositol-stabilised arginine silicate developed by Nutrition 21. Unlike standard L-Arginine, which is substantially metabolised by arginase in the gut before reaching the bloodstream, Nitrosigine® is absorbed more efficiently and generates nitric oxide at a significantly faster rate — achieving peak plasma arginine within 15 minutes vs 60+ minutes for regular L-Arginine.*

What are the performance benefits of Nitrosigine?

By rapidly increasing nitric oxide production, Nitrosigine® supports vasodilation — widening blood vessels to improve blood flow to muscles and the brain. Clinical studies show improvements in muscular endurance, reduced exercise-induced fatigue, and enhanced cognitive focus and processing speed. The dual benefit to both physical performance and mental clarity makes it valuable for athletes and those seeking cognitive support.*

When should I take this product for best results?

For exercise performance, take approximately 30 minutes before training. For general cardiovascular and cognitive support, it can be taken in the morning. Because Nitrosigine® raises arginine levels rapidly, there is no need for a long loading period unlike some other NO-boosting supplements.*

Can I stack this with Doctor's Best L-Arginine Powder?

Combining Nitrosigine® with additional L-Arginine increases total arginine intake. While not inherently dangerous for healthy adults, excessive arginine can cause GI discomfort at very high doses. Monitor your combined total intake and consult your healthcare professional if using multiple arginine-containing products.