Nattokinase Capsules

Nattokinase is the fibrinolytic serine protease that Bacillus subtilis var. natto secretes while fermenting cooked whole soybeans into natto. It is classified EC 3.4.21.62 and catalogued in MEROPS as subtilisin NAT (S08.044), placing it squarely in the subtilisin family; the mature chain runs to 275 amino acid residues with a theoretical mass of 27,726.74 Da. Thovek supplies it as a finished two-piece hard capsule, filled with a dried fermentation concentrate to the activity the buyer specifies, with bulk concentrate available separately for buyers who blend in-house. Activity, not weight, is what the trade buys. Potency is declared in fibrinolytic units, where one FU is the quantity of enzyme that releases 1 µg of tyrosine per minute under the fibrin assay conditions, so the capsule fill follows arithmetically from the concentrate: a 20,000 FU/g concentrate delivers 2,000 FU in a 100 mg fill, and the label figure carries a stability overage set from the formula. The second number to fix at enquiry is vitamin K2. Natto is the richest known food source of long-chain menaquinone — reported at 1,034 µg of vitamin K2 per 100 g, roughly 90% of it MK-7 — so the K2 carried along by a natto-derived concentrate is a formulation and labelling variable the buyer has to control. K2-reduced grades are available and the per-lot MK-7 result is reported either way. Origin and allergen status are simple but must be stated in writing. The ferment runs on soybean, so the material is declared as containing soy under EU Regulation (EU) 1169/2011 Annex II and US FALCPA unless the buyer holds validated soy-protein-free data on the specific lot. There is no milk, egg, fish, crustacean, peanut, tree nut or gluten input and no animal-derived material in the enzyme itself, so a vegetarian HPMC shell gives a fully vegan capsule; bovine gelatin shells are supplied where a buyer's range calls for them. Capsules are made in an FSSAI-licensed GMP facility and shipped with a batch certificate of analysis covering FU activity, MK-7 content, heavy metals and microbiology, alongside allergen, non-GMO, halal and kosher statements as required.