Systemic Enzymes Support:

  • Normal Respiratory Health*
  • Normal blood pressure
  • Healthy C-reactive protein levels*

  • Healthy response to inflammation*
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150 Capsules: $84.99 Now $74.99

300 Capsules: $164.99 Now $124.99

Serracor-NK Professional-Strength Systemic Enzyme Blend

Understand the Difference between Serracor-NK & Neprinol- Click on the “Compare” tab above.

Understanding Fibrin

Fibrin is an insoluble protein the body produces in response to bleeding or inflammation. Fibrin performs important functions in the body, including clotting and wound healing. During the blood clotting process, the protein precursor fibrinogen is converted into fibrin, which forms a layer of connective tissue inside the damaged blood vessel. To do this, the fibrin strands assemble into a net-like structure over the damaged vessel and harden, forming a “patch” or small clot to prevent further damage.3

Despite its protective function, excessive fibrin can do more harm than good. A high level of circulating fibrin has the potential to accelerate scarring, increase clot formation and impede normal blood flow. This can lead to increased blood viscosity, swelling, edema, pain, chronic inflammation and more serious fibrotic conditions or cardiovascular events.3

According to Scripps Research Institute, “It is generally assumed that the persistence of fibrin in the extra cellular matrix (connective tissue) promotes fibrosis, and that the extent of fibrosis is limited by proteases (protein-digesting enzymes) that remove the fibrin. Fibrotic disease occurs when normal control of this process is compromised and excess fibrous material accumulates in the tissues.”

Serracor-NK for Circulatory & Inflammation Support

Serracor-NK contains SEBkinase® with enteric coated serrapeptase and nattokinase, as found in the original Neprinol® formula. We are the original manufacturer of this formula, imitated by many others (to learn more about Serracor-NK vs. Neprinol, please click the "Compare" tab).

SEBkinase brings together two enteric coated, fibrinolytic proteases: Peptizyme-SP® (Serrapeptase) and NattoSEB® (our Nattokinase is Vitamin K-free, since it assists in blood coagulation). Serracor NK further supports the activity of SEBkinase-CV with a complete array of proteolytic enzymes, amylase, lipase, CoQ10, herbs and minerals. The net result is a comprehensive systemic enzyme blend designed to support maximum circulatory health.2

Serracor-NK also promotes healthy levels of C-reactive protein (CRP), an inflammation marker for inflammation and cardiovascular health.1 In addition, the entire systemic enzyme blend is manufactured in a ISO 9001:2000 and GMP certified facilities using our Bioactive Protein Peptide System® (BPPS).

Enteric coated Serrapeptase and Nattokinase: Why is it important?

Most nattokinase and serrapeptase brands on the market are not enteric coated, which means they can lose a significant portion of their fibrinolytic activity and effectiveness in the acidic environment of the stomach. The enteric coating of our Serracor-NK SEBkinase blend allows these sensitive enzymes to survive the acidic conditions of the stomach, thus allowing them to pass into the circulatory system maintaining high activity levels. 

The pH resistant enteric coating will disintegrate after it enters the alkaline environment of the intestines.  If your enzyme formula is not enteric coated, you may be wasting your money (to learn more about enteric coating used in AST Enzymes products, please click the"Compare" tab).

How do Fibrinolytic Units (FU's) relate to enteric coating?

Enzyme activity measured in fibrinolytic units does not mean anything if the enzymes are destroyed and/or denatured in the high acidic conditions of the stomach.  Under these conditions, our laboratory tests have consistently shown that serrapeptase and nattokinase lose significant activity when exposed to low pH (such as those in the stomach).  In contrast, our enteric coated nattokinase and serrapeptase (the original SEBkinase formula) perform at greater activity levels in the same low pH conditions.

Enzyme Stabilization with BPPS®

The Bioactive Protein Peptides System (BPPS) is a system of peptides used to stabilize and enhance the activity of enzymes.

The Bioactive Protein Peptides System was developed by Specialty Enzymes and Biotechnologies (SEB) specifically for enzyme stability. Stabilizers have been used since SEB began manufacturing enzymes in 1957. The BPPS system was a significant advancement developed by SEB in the early 1990's.

It is true it was not trademarked until 2008, but it was in use long before. The reality is: a pure enzyme is not stable. It requires the addition of stabilizers in order to provide a reasonable shelf life. Because we are the actual manufacturer of enzymes with more than 50 years of manufacturing experience, our research and development team constantly works to improve stability and tolerance to the environments in which the enzymes interact. Marketing companies, on the other hand, will generally have significantly less understanding of the physio-chemical and kinetic properties of enzymes.

Serracor-NK Dosage

For best results, begin enzyme regiment at a low dosage of 1 capsule three times a day. After three days, increase your Serracor-NK dosage to 2 capsules three times a day. After the first week, doses should be adjusted to a therapeutic level of 3 or more capsules three times a day (amount is dependent upon desired benefit).

NOTE: It is important to continue therapeutic doses until results are realized. This should then be reduced to a maintenance dose of 1-3 capsules three times a day.

Complementing your Serracor-NK with additional serrapeptase can support fibrin levels, as well as support a therapeutic internal balance. Peptizyme-SP contains 80,000 units of professional-strength serrapeptase per capsule.


1. Pais E, Alexy T, Holsworth RE Jr, Meise HJ. Effects of nattokinase, a pro-fibrinolytic enzyme, on red blood cell aggregation and whole blood viscosity. Clin Hemorheol Microcirc. 2006;35:139-142.

2. C.-H. Hsia et al. / Nutrition Research 29 (2009) 190-196.

3. John D. Ferryand Peter R. Morrison. Chemical, Clinical and Immunological Studes On The Products of Human Plasma Fractionation. XVI. Fibrin Clots, Fibrin Films, and Fibrongen Plastics.

Buy These Products Together and Save

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Buy Serracor-NK with Floracor-GI for Better Absorption.
Start your systemic enzyme therapy the right way. Increase the effectiveness of systemic enzymes by taking Floracor-GI with Serracor together. Floracor-GI is a blend of probiotics and enzymes for optimal intestinal health and greater nutrient absorption.

Combining the intestinal cleansing formula of Floracor-GI with the powerful systemic enzymes in Serracor-NK supports the body’s utilization of systemic enzymes, healthier circulation and inflammatory response.

1-Serracor-NK 300 capsules + 1-Floracor-GI 180 caps + 1-DigeSEB-GI 90 caps =$200.97 NOW $170.98

DigeSEB-GI is a broad-spectrum digestive enzyme blend for optimal digestion of all foods. DigeSEB-GI reduces stress on the gastrointestinal mucosa, which can boost immunity and decrease inflammation while enhancing the body’s nutrient intake and energy production.

BPPS® is a registered trademark of Specialty Enzymes and Biotechnologies.

Neprinol® is a registered trademark of Arthur Andrews Medical Inc., which is not affiliated with, nor sponsors or endorses this product or any other product from Specialty Enzymes & Biotechnologies or AST Enzymes.

Complete AST Enzymes Line of Products

  • Circulation & Inflammation | Serracor-NK
  • Total Body Therapy | Exclzyme
  • Joint & Inflammation | Exclzyme-2AF
  • Serrapeptase (80,000 SU) | Peptizyme-SP

Serracor-NK vs Neprinol


Serracor NK vs Neprinol**


Enteric coated Serrapeptase and Nattokinase

Enzyme Stabilizer BPPS®

Enzyme Manufacturing Source


Neprinol (2004-2008)





Neprinol   (Current)



Japan *










AST Enzymes recently learned of false claims, misstatements and misrepresentations by one of our competitors. These claims call into question the business practices of Specialty Enzymes and Biotechnologies and the quality of Serracor-NK.

Specialty Enzymes & Biotechnologies (SEB) is a major international manufacturer of enzymes for more than 20 industries, including the nutraceutical industry. Vic Rathi, president and founder of SEB, formulated the original Neprinol® for Arthur Andrew Medical (AAM), an enzyme marketing company. The proprietary formula remains the intellectual property of SEB; AAM was not privy to the formula.

SEBkinase® is a blend of enteric-coated nattokinase and serrapeptase, which was first introduced in commerce by SEB in 2002. Two years later, in 2004, SEB was contracted to formulate and make finished products, not raw material, for AAM and SEBkinase became an integral part of the original formula of Neprinol until 2008. During the duration of this contract:

  • SEB received no complaints, verbal or in writing, at any point about the quality and efficacy of Neprinol.
  • SEB did not provide any Neprinol product to AAM in 2009, so any complaints or refunds made thereafter were not for its products. A major distributor who worked with AAM at the time says they did not receive any complaints nor requests for refunds, and there was no apology issued to customers.
  • A review of the batches of Neprinol sold during that time shows activity levels were in accordance with AAM’s requests. In addition, the weight of the powder inside the capsules was within the accepted range of label claims and GMP Standards.
  • Initial production and sale of Serracor-NK was the result of feedback from previous Neprinol customers who contacted SEB as the manufacturer, requesting the original SEBkinase formula.

The quality of SEB products and services are evident in the fact that it has been in business for more than 50 years and continues to experience tremendous growth. In fact, in 2010 SEB expanded its manufacturing facilities, adding a new 25,000 square foot building to meet growing manufacturing demands. Thousands of satisfied customers can attest to the quality and efficacy of our products, and the integrity of our business practices.

Specialty Enzymes and Biotechnologies is an innovator; creating and manufacturing several of the best-selling enzyme supplements on the market today.

Please feel free to call us with questions.

Serracor-NK SEBkinase Formula Remains Unchanged

Specialty Enzymes did not change the formula for SEBkinase or the original formula for Neprinol, which is now available from AST Enzymes as Serracor-NK. Claims that we allegedly lowered the activity of SEBkinase in the original Neprinol formula are untrue. Our SEBkinase blend is unchanged since its introduction. The SEBkinase in Serracor-NK is the same as the SEBkinase in the original formulation of Neprinol. Nothing has changed but the name.

Enteric Coated Serrapeptase and Nattokinase

All enzymes have a pH range.  At the extremes of this range, whether acid or alkaline, systemic enzymes will denature (become irreversibly inactive). While it is true that most fungal and plant source systemic enzymes exhibit a fairly broad pH range, some bacterial sourced systemic enzymes are less tolerant of low pH. Because we are the actual manufacturer of our enzymes, we test them for both pH and temperature stability.  Based on the results of these kinetic studies, we have repeatedly demonstrated that serrapeptase and nattokinase are much less tolerant of a low pH and will begin to lose activity in acidic conditions consistent with the stomach.  Therefore, for maximum effectiveness, serrapeptase and nattokinase are best when enterically coated.

When we design a systemic enzyme blend for human consumption, we have to ensure that it will tolerate the pH variables of our gastrointestinal system. We have successfully done this with our systemic enzyme products, including Peptizyme SP (enteric coated serrapeptase), NattoSEB (enteric coated nattokinase) and SEBKinase (a blend of Peptizyme and NattoSEB).  As a result of our experience and expertise, our entire line of enteric-coated enzymes are able to reach the small intestine with higher activity for full systemic enzyme therapy.

Make an Informed Choice

There are several systemic enzyme products on the market today. In this case, there are two alternatives: an enzyme product from an expert manufacturer or one from a marketing company. You deserve the highest quality and most effective enzyme products available. We encourage you to make an informed choice.


Enteric Coating Comparison


Methacrylic Acid Copolymer


Cellulose Acetate Phthalate (CAP)

Hydroxypropyl Methylcellulose Phthalate (HPMCP)

Acid Armor®
(extra-thick cellulose layer)**

Contains Phthalates





Considered Enteric Coating





Studies supporting Efficacy as Enteric Coating















Time in Use


>50 years


>70 years


~40 years


~1 year



*AST Enzymes uses MAAC as enteric coating


What is enteric coating, and why is it needed?

Enteric coating is a layer of protective coating for dietary supplements that is meant to allow the supplement to bypass digestion by the stomach and be absorbed in the small intestine. Systemic enzymes are proteins, so their functional structures are denatured (or destroyed) in conditions of extreme pH and temperature. Without enteric coating, enzymes would be rendered useless long before they reach the bloodstream, where their carry out their beneficial effects.

What’s enteric coating made of?

At AST Enzymes, we use Methacrylic Acid Copolymer (MAAC) for our enteric coating. Methacrylic Acid Copolymer (MAAC) is not a phthalate. According to independent studies, MAAC is the most gastro-resistant when compared to other commonly used enteric coating agents such as Cellulose Acetate Phthalate (CAP) and Hydroxypropyl Methycellulose Phthalate (HPMCP). This means that MAAC can most effectively withstand the acidity of the stomach, allowing its contents to be released in the small intestine and absorbed successfully.

Don’t let the name scare you. MAAC is a food-grade compound that has been in use as enteric coating in the pharmaceutical industry for over 50 years with no reported side effects. In fact, the European Food Safety Authority – an organization that conducted studies which led to the ban of 6 types of phthalates in personal care products in Europe in 2004 – has deemed MAAC safe for use as coating agent in food supplements.

Not only is MAAC listed as Generally Recognized As Safe (GRAS) by the Food and Drug Administration (FDA), the Environmental Protection Agency (EPA) also conducted various studies and found sufficient information to reasonably conclude that the current use pattern of MAAC will not adversely affect public health or the environment.

** Neprinol® and Acid Armor® are registered trademarks of Arthur Andrews Medical Inc., which is not affiliated with, nor sponsors or endorses this product or any other product from Specialty Enzymes & Biotechnologies or AST Enzymes.


Nattokinase Research:  Fibrinoyltic Activity

In vitro and in vivo studies have consistently demonstrated the potent fibrinolytic effect of Nattokinase.1   A review of the research on nattokinase demonstrates it may help avoid or reduce the likelihood of deep vein thrombosis, cardiac infarction, pulmonary emboli and stroke.  It appears to accomplish this via its fibrinolytic, anti-inflammatory and modulating effect on blood pressure.  Studies on hypertension demonstrate an average drop of 10.9% in systolic blood pressure and a 9.7 percent drop in diastolic blood pressure.2,3,4

A study conducted with natto on 12 healthy adults (6 men and 6 women, between the ages of 21 and 55) sought to demonstrate fibrinolytic activity.  The volunteers were given 200 grams of natto (the food) before breakfast, and their fibrinolytic activity was tested over time.  The results indicate natto generates an increased ability to dissolve blood clots.  As a control, researchers later fed the same amount of boiled soybeans to the same volunteers and tracked their fibrinolytic activity.  The tests showed no significant change.5

The accumulation of fibrin in blood vessels significantly increases the likelihood of thrombosis formation resulting in a cardiovascular event.  For thrombolytic therapy, microbial fibrinolytic enzymes are now much more accepted.  The physiochemical properties of this enzyme is becoming well characterized and its effectiveness in thrombolysis in vivo has been further identified.6,7

Nattokinase Benefits & Blood Clots

Blood clots (thrombi) form when strands of fibrin accumulate in the circulatory system.  These clots can cause blockage of blood flow.  If blood flow is blocked, the oxygen supply to that tissue is cut off and it eventually dies.  In the heart, this can result in myocardial infarction (heart attack).  In the brain, it can result in strokes or mini-strokes.  Deep vein thrombosis can result in pulmonary emboli.  All these events can be life-threatening. An in vitro study not only demonstrated the powerful fibrinolytic activity of nattokinase, but also showed the significant reduction in the aggregation of red blood cells and overall lowered whole blood viscosity.  The net results are vascular conditions that are less likely to produce blood clots. The authors suggest that nattokinase possesses very real potential as a therapeutic agent in cardiovascular health.8

The process of forming a clot is complex and involves several enzymes.  However, the body mainly produces one central enzyme for dissolving a clot, plasmin.  It happens that the properties of nattokinase are very similar to plasmin.  Nattokinase is particularly effective because it enhances the body's natural ability to fight blood clots in several different ways.  It dissolves fibrin directly and appears to enhance the body's natural production of both plasmin and other clot-dissolving enzymes like urokinase.  An in vivo study was undertaken to demonstrate the thrombolytic activity of nattokinase, plasmin and elastase on an induced clot in the common carotid artery of laboratory rats.  A review of the results indicates that the thrombolytic activity of nattokinase is stronger than that of plasmin or elastase in vivo in this model.9

A fascinating study was conducted to measure the effect of nattokinase in the prevention of deep vein thrombosis and superficial vein thrombosis on extended flights of 7-8 hours on high-risk individuals. The nattokinase group had no thromboses.  The placebo group had 5 deep vein thromboses and 2 superficial vein thromboses or 7.6% of 94 individuals.  After the flight, the degree of edema was increased by 12% in the placebo group and decreased by 15% in the nattokinase group.  The authors concluded that nattokinase was effective in reducing thrombotic events and in controlling edema in high-risk subjects on long flights.10

Serrapeptase Benefits and Respiratory Health

When it comes to the respiratory system, we are constantly at risk of developing health problems, anywhere from the common cold to severe lung diseases. While the cause of any given condition may differ, often time symptoms can manifest themselves and be addressed in similar ways. Clinical testing of serrapeptase reviews its potential with many aspects of respiratory health.

Serrapeptase is widely used in clinical practice in Japan. One research trial in Japan investigated the effect of serrapeptase on sputum properties and symptoms in patients with chronic airway diseases. After 4 weeks of serrapeptase treatment, sputum output, viscosity and sputum neutrophil count decreased significantly. In addition, the frequency of coughing and of expectoration also decreased. The researchers concluded serrapeptase may exert a beneficial effect on mucus clearance by reducing neutrophil numbers and altering the viscoelasticity of sputum in patients with chronic airway diseases.11

Another clinical study reviwed the effect of serrapeptase on the elasticity and viscosity of the nasal mucus in adult patients with chronic sinusitis. Serrapeptase was administered orally for 4 weeks. The dynamic viscosity of the mucus at week 4 was significantly lower than that at week 0. The authors conclude that serrapeptase may have some application in patients with chronic sinusitis.12

The efficacy of serrapeptase was evaluated in a multicentre, double-blind, placebo-controlled study of 193 subjects suffering from acute or chronic ear, nose or throat disorders. After 3-4 days' treatment, significant symptom regression was observed in serrapeptase treated patients. Statistical comparison confirmed the greater efficacy of serrapeptase against all the symptoms examined. It was concluded that serrapeptase has anti-edemic and fibrinolytic activity and supports the body’s healthy immune system.13

Enzyme Activity:

Enzymes & Herbs

How it Works


Derived from natto, a traditional Japanese food made from fermented soybeans. Natto has been known for centuries for its positive medicinal properties, particularly for cardiovascular disorders. To make nattō, soybeans are fermented with the beneficial bacteria Bacillus natto (sometimes listed as Bacillus subtilis natto). During fermentation, the Bacilli produce enzymatic proteases, the most important of which is nattokinase. Like other proteases, nattokinase has potent anti-inflammatory activity, as well as several other beneficial properties, including fibrinolytic activity.* A researcher, Hiroyuki Sumi, identified the active enzyme in natto and demonstrated its ability to dissolve vascular blood clots. He called this enzyme “nattokinase,” meaning “enzyme in natto.”


Derived from a species of bacteria originally found in the intestine of silkworms; the bacteria, Serratia mercesans, produces the enzyme that enables the silkworm to dissolve its silken cocoon and emerge after metamorphosis. Serratia is now grown in cultures to produce serrapeptase by fermentation. Numerous research and clinical studies demonstrate serrapeptase’s formidable  proteolytic (protein dissolving), mucolytic (mucus dissolving) and fibrinolytic (fibrin dissolving) properties. They also show that scar tissue is greatly reduced and proteins involved in the immune response are effectively digested. Serrapeptase is a protease that has been used in Japan and Europe for over four decades for its role in the immune system.*


A collective name for the proteolytic (protein-digesting) enzymes found in the pineapple plant (Ananas comosus); known for its digestive as well its anti-inflammatory properties. A good substitute for animal-derived enzymes pepsin and trypsin for both digestive and systemic support due to its activity across a wide pH range*


Obtained from the latex of the fruit of the Papaya tree (Carica papaya); used for centuries as an effective digestive aid.


Catalyzes the break-down of fats into essential fatty acids that are needed for healthy tissues and cells*


Hydrolyze (break-down) proteins like meat, casein, gelatin, soy, fish and other plant and animal proteins to smaller chains of polypeptides (small proteins) and amino acids for easier uptake throughout the body.


Bioflavonoid; strengthens and tones arteries and veins, and provides antioxidant support against free-radicals and inflammation*


Also known as Indian gooseberry (Emblica officinalis); it is a natural, efficacious antioxidant and is one of the richest sources of absorbable vitamin C.


An essential enzyme and cofactor in metabolism that is naturally made and stored in the liver, kidneys and heart; a vital part of energy production and overall cell health*


An essential mineral used as a co-factor by over 350 enzymes in the body; critical part of cardiovascular and nerve physiology. Magnesium helps relax arteries and assists in proper nerve impulse function*




1. Enhancement of the Fibrinolytic Activity in Plasma by Oral Administration of NattokinasesActa Haematol1990; 84:139-143. Hiroyuki Sumia, Hiroki Hamadab, Koichiro Nakanishic, Hajime HiratanicaDepartment of Physiology, Miyazaki Medical College, Miyazaki, Japan;bDepartment of Biochemistry, Oklahoma State University, Okla., USA;cBiochemistry Research Laboratories, JCR Pharmaceuticals, Kobe, Japan

2. Prevent Heart Attack and Stroke with Potent Enzyme that Dissolves Deadly Blood Clots in Hours.Health Sciences Institute, March 2002.

3. Effect of Natto Diet on Blood Pressure.JTTAS, 1995. Maruyama M, Sumi H..

4. Effects of Nattokinase on Blood Pressure: A Randomized, Controlled Trial. Hypertension Research 31, 1583–1588 (2008) Ji Young Kim 1,2, Si Nae Gum2,3, Jean Kyung Paik2,4,5,

5. Purification and Characterization of a Strong Fibrinolytic Enzyme (Nattokinase) in the Vegetable Cheese Natto, a Popular Soybean Fermented Food in Japan. Biochemical and Biophysical Research Communications, Vol. 197, Issue 3, 30 December 1993, pp. 1340-1347 Fujita M., Nomura K., Hong K., Ito Y., Asada A. and Nishimuro S. Jcr Pharmaceut Co Ltd, Biotechnol Res Labs, 3 2 61 Takatsukadai, Nishi Ku, Kobe 65122, Japan

6. Microbial fibrinolytic enzymes: an overview of source, production, properties, and thrombolytic activity in vivo. Applied Microbiology and Biotechnology Vol. 69, No. 2, November, 2005, pp- 126-132

7. Nattokinase for prevention of thrombosis. Am J Health Syst Pharm, 63(12): 1121-3 2006
Tai MW , Sweet BV

8. Effects of nattokinase, a pro-fibrinolytic enzyme, on red blood cell aggregation and whole blood viscosity. Clin Hemorheol Microcirc 2006; 35(1-2):139-42. Pais E, Alexy T, Holsworth RE, Meiselman HJ

9. Thrombolytic Effect of Nattokinase on a Chemically Induced Thrombosis Model in Rat. Biological & Pharmaceutical Bulletin Vol.18 , No.10 (1995) pp.1387-1391 Mitsugu Fujita1, Kyongsu Hong1, Yae Ito1, Rie Fujii2, Kimio KARIYA2 and Satoshi NISHIMURO3

10. Prevention of Venous Thrombosis in Long-Haul Flights with Flite Tabs: The LONFLIT-FLITE Randomized, Controlled Trial Angiology, Vol. 54, No. 5, 531-539 (2003) M.R. Cesarone, et al.

11. Effect of the proteolytic enzyme serrapeptase in patients with chronic airway disease. Nakamura S, Hashimoto Y, Mikami M, Yamanaka E, Soma T, Hino M, Azuma A, Kudoh S. Respirology. 2003 Sep;8(3):316-20. Department of Respiratory Medicine, Tokyo Metropolitan Hiroo General Hospital, Japan.

12. The effect of an orally administered proteolytic enzyme on the elasticity and viscosity of nasal mucus. Arch Otorhinolaryngol. 1988;244(6):355-9. Department of Otorhinolaryngology, Mie University School of Medicine, Japan. Majima Y, Inagaki M, Hirata K, Takeuchi K, Morishita A, Sakakura Y.

13. Evaluation of Serratia peptidase in acute or chronic inflammation of otorhinolaryngology pathology: a multicentre, double-blind, randomized trial versus placebo. J Int Med Res. 1990; 18(5):379-88. Institute of Clinical Otorhinolaryngology, University of Naples, Italy. Mazzone A, Catalani M, Costanzo M, Drusian A, Mandoli A, Russo S, Guarini E, Vesperini G.


What is systemic enzyme therapy?

Systemic enzyme therapy refers to the therapeutic use of natural enzymes to produce a desired effect. Systemic enzymes are absorbed from the small intestine where they enter the bloodstream and execute their effects on the entire body as a system. Their crucial role in normal inflammatory response assists and supports the body in accelerating healing.


What is a systemic proteolytic enzyme?

Proteolytic enzymes break down proteins into their building-blocks, which are called amino acids. Systemic proteolytic enzymes are responsible for breaking down accumulated protein and waste substances found in the circulatory system and connective tissue. Waste materials produced from inflammation and other biochemical processes can build up, contributing to excessive scarring and perpetuated immune responses. Excessive scarring, particularly of the organs, can exacerbate symptoms of the associated disease. The waste product of specific concern is known as fibrin. Regular systemic proteolytic enzyme use can promote circulation and support flushing out these waste products.


 What is fibrin?

Fibrin is a protein-based substance that is needed to help clot one’s blood, playing a substantial role in immune response and healing. When the body responds to injury or chronic inflammation, fibrin is recruited to the damaged area to form scar tissue. Although the body is equipped with plasmin, a naturally occurring enzyme responsible for breaking down excess fibrin, some people are at a disadvantage – as aging occurs, plasmin levels progressively decrease. This actually increases the risk for excessive, undesirable scar tissue formation in the body.


Are systemic enzymes anti-inflammatory drugs?

Although systemic enzymes produce anti-inflammatory effects, they are not considered a drug. Since enzymes are naturally occurring within the body, systemic enzyme therapy is considered supplementation. One difference between systemic enzymes and NSAIDs (Non-steroidal anti-inflammatory drugs) involves the duration of action. While NSAIDs produce short-term pain relief, systemic enzymes can produce long-term alleviation with appropriate use. The largest difference between NSAIDS and systemic enzymes is the mechanism of action and possible side effects. NSAIDs block the production of prostaglandins, which are responsible for inflammation and swelling. However, prostaglandins protect the lining of the stomach, and prolonged use of NSAIDs can reduce this protection and increase the risk of developing ulcers. Conversely, regular use of systemic enzymes has no negative side effects and can actually provide protective effects against excess inflammation.


Why is it important to take Serracor-NK on an empty stomach?

Since most absorption occurs in the small intestine, the systemic enzymes must bypass the stomach to gain access there. If the enzymes are taken with food, they will likely begin working to break down your food within the stomach, rather than passing through to the small intestine. Taking systemic enzymes like Serracor-NK with food will compromise their absorption, as well as their effectiveness.


Does Serracor-NK have an enteric coating?

Yes, the serrapeptase and nattokinase in Serracor-NK are enterically coated. While similar systemic enzymes may have the same active ingredients, most do not utilize enteric coating. The purpose of enteric coating is to protect the enzyme from the acidic environment of the stomach. High activity level is preserved until the enzymes reach the small intestine, where absorption into the bloodstream takes place. While the enteric coating can withstand the acidic environment of the stomach, the alkaline environment of the small intestine will disintegrate the enteric coating, allowing the enzyme to become active within the bloodstream.


Do you use phthalates in your enteric coating?

No, our enteric coating does not use or contain phthalates. At AST Enzymes, we use Methacrylic Acid Copolymer (MAAC) for our enteric coating. Compared to other commonly used enteric coating agents such as Cellulose Acetate Phthalate (CAP) and Hydroxypropyl Methycellulose Phthalate (HPMCP), MAAC is the most gastro-resistant and does not carry the same risks. Additionally, MAAC is considered GRAS (Generally Recognized as Safe) by the FDA and is approved for use by the European Food Safety Authority.To learn more about enteric coating used in AST Enzymes products, please click the "Compare" tab.


How long should I take Serracor-NK before feeling results?

Since people experience varying ailments and severity of disease, the length of time to include systemic enzymes in your regimen may vary as well. As an overall guideline, it is typically recommended that new systemic enzyme users start off slow. A starter dose is generally one capsule, three times daily. After three to four days of proven tolerance, the dose can be increased to a therapeutic dose of 3 capsules, 3 times per day. At this point, results may be monitored, and dosage should be adjusted accordingly. Some consumers find their therapeutic dose between 9-12 capsules per day, while others only need 3-6. There are several factors that may affect results and required dosage, including:




Severity of symptoms


Time of administration (Better absorbed on an empty stomach)

Adherence to regimen

Nutritional state


What if I miss a dose?

Regular, consistent use of systemic enzymes will provide the best results, however missed doses of systemic enzymes do not have serious repercussions. Although symptoms alleviated by systemic enzyme therapy may resurface, getting back on track by remembering to take your next dose will suffice. There is also the option of incorporating another dose during the day. There is no need to “double up,” on one dose - and remember, systemic enzymes are best absorbed on an empty stomach.


Does Serracor-NK have any side effects?

The use of Serracor-NK has not been shown to exhibit detrimental effects, neither long term nor short term. Just as dosage requirements vary, side effects may vary as well. Although gastrointestinal disturbances have been reported by a small percentage of new users, tolerance is maintained once the dosage is adjusted. Minor allergic reactions, like reddening of the skin, are also rare occurrences, and can be seen with extremely high doses. There are no known interactions with prescription or over the counter drugs while using systemic enzyme therapy. However, it is recommended that you consult with your physician about starting systemic enzymes, especially if you are currently on blood-thinning medications or if you are pregnant or nursing.


Can I take Serracor-NK with other systemic enzymes?

Systemic enzymes may be taken together, yielding desirable results, as long as they are taken on an empty stomach. In fact, it is often recommended that systemic enzymes be combined. Products like Serracor-NK and Peptizyme-SP often have synergistic effects when taken together. This means that the separate products work together to produce advantageous results. By combining and enhancing the activity of the enzymes, their effects on the healing process are more attainable.


Can I take Serracor-NK with digestive enzymes?

Although digestive and systemic enzymes are not contraindicated in terms of ingredients, they cannot be taken at the same time. The purpose of digestive enzymes is to aid in digestion of specific foods, so taking them with food is an obvious recommendation. Because systemic enzymes require an empty stomach for maximum absorption, they must be taken separately from digestive enzymes. There are no adverse interactions between systemic and digestive enzymes, but they serve different purposes and thus should be taken as directed for best results.

Supplement Facts

Serving Size: 1 Capsule
Servings Per Container: 150 or 300

Amount Per Serving:                          %DV

Serracor-NK® Blend                       500 mg          *
  SEBkinase® Blend:                   15,000 FU
    NattoSEB® (Enteric coated
    Nattokinase), Peptizyme SP® EN
    (Enteric coated Serrapeptase)

  Enzyme & Cofactor Blend:
    Bromelain, Papain, Lipase,
    Proteases, Rutin, Amla,
    Coenzymes Q10
    & Magnesium

*Daily Value (DV) not established

Other ingredients:  Microcrystalline cellulose and cellulose (vegetarian capsule)

Directions: Take 1 to 2 capsules three times a day. In three days, if desired benefit is not achieved, increase to 2 to 3 capsules three times a day. Take capsules 30 to 60 minutes before or 2 hours after a meal with 8 oz. of water. Dosage can be increased or reduced as needed to achieve desired benefits.

Store in cool, dry place with the lid tightly closed. Avoid excessive heat. Keep out of the reach of children. Caution: If you are taking anticoagulants, like warfarin type drugs, do not take this without consulting your physician. If you are pregnant, nursing, taking any medication or under medical supervision, consult your doctor before use. Discontinue use and consult your doctor if any adverse reactions occur. Not intended for use by persons under the age of 18.

This Product does not contain soy.

Non GMO Free of pesticides, chemicals, preservatives, animal derivatives, dairy, lactose, yeast, fish or shellfish, peanuts, tree nuts, artificial sweeteners and colors.
Professional Strength

All individual enzymes and probiotics are kosher-certified, and suitable for vegetarians and vegans.


Bioactive Protein Peptide System (BPPS®) is a proprietary manufacturing process featuring complementary bioactive peptides, ensuring greater enzyme stability, absorption and bio-availability.

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