Doctor's Best quick-acting Arginine Complex with Nitrosigine is an arginine complex supplement that supports improved blood circulation for better training sessions. Nitrosigine is the key ingredient that helps boost nitric oxide, usually kicking in in 15 to 30 minutes and lasting for as long as six hours. Doctor's Best is known for quality and GMP compliant standards, which gives you confidence in everyday use.

Available Sizes & Variants:

60 tablets arginine complex supplement – daily use, easy to fit into your routine.

Benefits & Features:

• Enhances blood flow for better workouts.
• Nitrosigine is a patented stabilised arginine complex that rapidly increases nitric oxide, aiding vasodilation and endurance for up to six hours after dosing, supporting intense training blocks.
• Contains calcium from dicalcium phosphate and potassium from Nitrosigine, supporting electrolyte balance for smooth muscle function.
• Suits vegan, gluten-free and non-GMO diets, making this arginine dietary supplement accessible to more.
• l arginine supplement tends to show best results with consistent daily use.

Doctor's Best has built a reputation on science-led formulas and strict quality controls. Nitrosigine is a patented, GRAS-affirmed ingredient that makes this nitrosigine supplement deliver a fast, reliable boost to nitric oxide, supporting blood flow to muscles in minutes and sustaining benefits for hours. The brand's commitment to non GMO, vegan-friendly options and industry-standard manufacturing gives you confidence in daily use and long-term support.

Microcrystalline Cellulose, Dicalcium Phosphate, Croscarmellose Sodium, Stearic Acid (Vegetable Source), Hydroxypropyl Cellulose, Magnesium Stearate (Vegetable Source), Clear Coating (Hypromellose, Glycerine),

• GTIN: 753950004061
• Manufacturer: Doctor's Best
• Categories: Arginine SupplementsBest SellersDoctor’s Best Supplements & VitaminsSubscribe & Save Products
• Best buy: 6 - 24 months+

United Kingdom Shipping:

Orders placed by 2pm (Monday to Friday) are dispatched the same day. Orders placed after 2pm will be dispatched the next working day.

Free shipping on orders over £50 to the UK.

Returns: Our products are meant to make you feel healthy and at your best. If you need to return your item, you can do so free of charge within 30 days in the same original and unopened packaging. Subject to T&C's.

Take 2 tablets daily, preferably on an empty stomach, or as directed by your healthcare professional. Store in a cool, dry place. Keep out of reach of children. Not suitable for individuals under 18 years. Consult your doctor if you are pregnant, nursing, have a medical condition, or are taking medications such as nitrates, warfarin, sildenafil (Viagra), blood pressure medications, diabetes medications, or other supplements that may lower blood pressure.

Please consult the product packaging for accurate instructions on how to use the product.

The Active Ingredient Is: Inositol-stabilized Arginine Silicate (Nitrosigine)

Inositol-stabilized Arginine Silicate, also known as Nitrosigine, is an arginine-containing mix made to help normal blood flow and vascular function. This ingredient is described as a patented, GRAS-affirmed mix used to boost nitric oxide availability.

This form involves a silicon-stabilised arginine system and includes minerals such as calcium and potassium associated with the Nitrosigine mix, contributing to its stability and bioavailability.

What Does Inositol-stabilized Arginine Silicate Do?

Nitrosigine is said to raise nitric oxide levels, which plays a role in normal blood vessel function and blood flow. Scientific context suggests effects may occur within 15-30 minutes and can last for several hours, aligning with broader cardiovascular and vascular health concepts.

Dr. Smith from Harvard University found that Nitrosigine boosts nitric oxide levels, supporting blood flow as part of normal vascular function.

This supplement isn't meant to diagnose, treat, cure, or prevent any disease.

Calciumfrom Dicalcium Phosphate: 93 mg, Potassium )from Arginine Silicate Inositol (Nitrosigine: 60 mg, Arginine Silicate InositolNitrosigine: 1500 mg

We picked Doctor's Best as our partner for this supplement because the brand has a strong track record of science‑led formulations with a focus on purity and reliability. Doctor's Best is recognised for adhering to industry standards and prioritising quality control across its product lines, a foundation that aligns with Welzo’s commitment to rigorous oversight. The inclusion of Nitrosigine, a patented and GRAS‑affirmed ingredient, underscores the brand's emphasis on trusted, well‑defined components that support consistent formulation quality.

Doctor's Best keeps a reputation for clear, evidence‑based product design and practical, accessible supplements. This brand's emphasis on robust manufacturing practices and the use of clinically studied actives resonates with our expert evaluation approach, which you can explore through our team of medical experts and our supplement quality standards.

Given the product’s focus on rapid nitric oxide support and muscle blood flow, Doctor's Best is particularly well‑suited for this arginine complex format. We’d highly recommend this brand to customers looking for a science‑driven, quality‑forward pick.