Nattokinase 100mg vs 200mg: Which One Is Right for You?

What FU Actually Measures

Nattokinase is an enzyme, and enzymes are usually described by how active they are, not just by how much they weigh. That's why nattokinase supplements are labelled in Fibrinolytic Units (FU) alongside their milligram weight. FU reflects the enzyme's measured activity in a standardised laboratory assay — essentially, how much clot-dissolving work a given amount of the enzyme can perform under controlled conditions.

This is a useful distinction to understand before comparing products, because two capsules with different milligram weights can still deliver meaningfully different levels of enzyme activity. For nattokinase specifically, weight and FU tend to scale together in a predictable way, which is why you'll usually see both numbers quoted side by side on the label.

100mg vs 200mg: What's Different

On the Aiva Wellness range, the difference between the two products is straightforward: the 200mg capsule delivers roughly double the fibrinolytic activity of the 100mg capsule in a single serving.

• Nattokinase 100mg — provides 2,000 FU per capsule, with 60 capsules per pack (roughly a two-month supply at one capsule daily).
• Nattokinase Plus 200mg — provides 4,000 FU per capsule, with 30 capsules per pack (roughly a one-month supply at one capsule daily).
• Same source, same process — both are derived from fermented soybean (natto) via the same fermentation-based extraction, just standardised to different potencies.

Neither strength is universally "better" than the other — they are simply different concentrations of the same natural enzyme, and the more appropriate one depends on factors specific to you.

How to Read a Nattokinase Label

Whichever strength you're considering, a few label details are worth checking before you buy:

• Serving size and servings per container — so you know exactly how long a pack will last at the labelled serving.
• FU rating, not just milligrams — this tells you the enzyme's actual measured activity.
• Other ingredients — look for a short, transparent list of diluents, glazing agents, and capsule shell components, with nothing unexplained.
• Allergen information — nattokinase is derived from soy, so allergen labelling matters if you have a soy sensitivity.

Factors People Commonly Consider

We are not going to tell you which strength is right for you — that genuinely depends on your own health picture, and it's a conversation worth having with a doctor. That said, here are the kinds of factors people commonly weigh when they raise the topic with a healthcare professional:

• Existing routine — whether nattokinase is a new addition or one of several supplements already being taken.
• Capsule preference — some people prefer fewer, higher-potency capsules; others prefer to start at a lower potency.
• Medical history — including any blood-thinning medication, clotting disorders, or upcoming surgery.

Safety Considerations for Both Strengths

Both the 100mg and 200mg products are manufactured using the same standardised process and carry the same general safety considerations. Nattokinase is typically taken on an empty stomach, since food can slow the enzyme's absorption. As with any fibrinolytic enzyme, anyone on anticoagulant or antiplatelet medication, with a bleeding or clotting disorder, or scheduled for surgery should speak with a doctor before use, regardless of the strength being considered.

If cardiovascular wellness is already on your radar, you may also find it useful to read our overview of what nattokinase is and where it comes from, or our deeper look at what 4,000 FU means on the Nattokinase Plus 200mg label.

Frequently Asked Questions

The Takeaway

Nattokinase 100mg and 200mg are two potencies of the same natural, fermentation-derived enzyme — the right one for you depends on your individual routine and health picture, not a universal rule. Read the FU rating, check the label carefully, and loop in your doctor before deciding which fits your daily wellness routine.