Natto-Serra by Doctor's Best delivers circulatory support and immune calm through nattokinase and serrapeptase, a vegan, non-GMO enzyme blend crafted for optimal intestinal delivery. Developed by Doctor's Best, a name rooted in enzyme science and quality, it uses Serrateric coating to optimise delivery. The vegan, non-GMO mix supports everyday wellbeing, without allergens that annoy some.

Available Sizes & Variants:

90 capsules — convenient daily dose for ongoing circulatory support

Benefits & Features:

• Supports healthy circulation with natural fibrinolytic action.
• Delivers nattokinase and serrapeptase in a protected, easy to absorb form through Serrateric coating, helping enzymes reach the gut intact and promote smoother blood flow to support circulatory comfort and daily activity.
• Vegan, non-GMO formulation suits plant-based lifestyles while avoiding common allergens and fillers.
• Synergistic enzyme blend supports circulatory flow and immune function, as observed in some studies.
• Doctor's Best backing means strict sourcing and Serrateric coating that protects enzymes until the intestine, helping you feel steadier throughout the day.

Doctor's Best Natto-Serra sits on a solid heritage of enzyme science and practical manufacturing. Serrateric coating protects the enzymes until they reach the intestine, helping delivery feel smoother than older coatings. Natto-Serra blends nattokinase from natto with serrapeptase from Serratia E-15 in a vegan soy based formula that avoids common allergens. This blend has earned a loyal following among health enthusiasts seeking natural circulatory support with a clean ingredient list. Some customers pair it with probiotics, n acetylcysteine, or a vitamin d supplement for broader wellness.

Serrapeptase enzyme (from Serratia sp.) 40,000 SPU, Nattokinase (from fibrinase enzyme) 2,000 FU, Calcium (from tricalcium phosphate and calcium stearate in SerratericTM) 29 mg, SerratericTM (maltodextrin, tricalcium phosphate, calcium stearate, medium chain triglycerides), delayed release capsule (hypromellose, gellan gum, purified water). Contains Soy.

• GTIN: 753950002944
• Manufacturer: Doctor's Best
• Categories: CHECKOUT UPSELLDoctor's Best
• 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 1 capsule daily without food, or as recommended by a nutritionally informed physician. Store in a cool, dry place. Not recommended for individuals who are pregnant, lactating, allergic to soy, or have poor digestion. Consult a physician before use if taking blood thinners. Stop taking if you experience nausea, vomiting, or stomach upset.

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

The Active Ingredient Is: Nattokinase

Nattokinase is a proteolytic enzyme derived from natto, used to support normal circulatory function through enzymatic activity.

This formulation includes nattokinase in a vegan, non-GMO context with Serrapeptase as a supporting enzyme; the coating technology aids enzyme delivery to the intestines.

What Does Nattokinase Do?

Nattokinase is involved in the breakdown of fibrin, with research suggesting a role in promoting healthy circulation as part of a broader enzymatic blend.

Dr. Sumi of University of Tokyo found that nattokinase acts as a fibrinolytic enzyme that can contribute to normal vascular function, supporting EFSA-aligned functions for proteolytic enzymes.

This product is not intended to diagnose, treat, cure, or prevent any disease.

Why Doctor's Best Natto-Serra is Welzo Selected

We decided on Doctor's Best as our supplier for Natto-Serra because this brand embodies enzyme science and quality at the heart of its approach. Doctor's Best is recognised for developing enzyme-based formulations and uses Serrateric coating to boost intestinal delivery, supporting the product's intended role in circulatory and immune health. The brand prioritises vegan, non-GMO ingredients and provides vegetarian capsules, matching Welzo’s commitment to high-purity, ethically produced supplements.

Our vetting criteria centre on brand credibility, production philosophy, and testing integrity. Doctor's Best shows a genuine specialty in proteolytic enzyme tech, which resonated with our team as a strong fit for this enzyme-based supplement. The formula—nattokinase and serrapeptase with the Serrateric coating—was evaluated for delivery and formulation, ensuring it matches the intended health-support profile. This brand was thoroughly evaluated by our medical team for compliance with the standards we enforce.