One of the Best. Nutricology is highly researched, and their products are second to none. They remove the Vitamin K2 from this product (99% I believe), so it is my personal belief / opinion that it can be safely used by those who are on pharmaceutical blood thinners (e.g. Warfarin). However, I am NOT a doctor, nor a representative of the company, so this is my opinion only.
My father was diagnosed with 3 blood clots in his legs during a time of recovery at home following major surgery. He used this product every day and 5 days later he was tested again by the same doctor and the clots were gone/clear on the ultrasound. We have used this product intermittently ever since, and have come rely on it as effective. I have also come to the personal conclusion that it is the safest readily available natto supplement on the market.
Taking nattokinase following a few health events. Underlying condition of cancer, had sepsis a few years earlier, which in turn affected my cardiovascular system and it was a ? mini stroke that made me look at this product. I researched carefully first, read the literature from Japan on it. Began on another brand which was excellent. Although not able to prove it, I feel that it was taking Nattokinase that has also made an unexpected improvement in heart rhythm (LBBB) over the course of that year. I wondered if it was really working until I accidentally cut my hand....then part of that question was answered:). Then that product was discontinued. Stopped taking the nattokinase for about six months. Recently ended up in an ambulance again with what turned out to be a possible clot...again. Other than initial tachy of 135, ECG now perfect (their words not mine) no LBBB evident. Eventually sent home still not feeling that great (chest, neck ache). So back on this brand of nattokinase straight away. Took about a week to feel better. Planning to stay on a half dose (one capsule) permanently. Natto is extensively used in Japan, I wish that western medicine would take a close look at it. I have read of a few NZ patients who could not take Warfarin, who take nattokinase under the care of their specialists. This particular brand is the only one (I believe) endorsed by the Japanese (production).