Serracor-NK®
A patent-pending formula backed by decades of customer satisfaction. Serracor-NK® is power-packed with two synergistic fibrinolytic enzymes – acid-resistant serrapeptase and acid-resistant nattokinase – and boosted with herbs, antioxidants, and other enzymes, for a potent overall effect.*
How to Take
Must be taken on an empty stomach with a large glass of water (30-60 minutes before or 2 hours after meals). Dosage varies by indivudual and should be monitored closely.
One approach that has worked for many is:
- Days 1-5: Take 1 capsule, 3 times a day.
- Days 6-11: Take 2 capsules, 3 times a day.
- Therapeutic Dose: Take 3 capsules, 3 times a day.
- Maintenance Dose: Every body is different. Monitor your body closely as you increase to the Therapeutic Dose. After desired effect has been reached, reduce slowly until you find what amount continues to work for your body. On average, this is 1-2 capsules fewer per day than the Therapeutic Dose.
Supplement Facts
Choose options
Supports a Healthy Response to Inflammation*
Promotes Normal Blood Viscosity*
Ingredients Found in Nature
SEBkinase®
A combination of two potent fibrinolytic enzymes: acid-resistant serrapeptase and acid-resistant nattokinase. Individually, each enzyme is a powerhouse with applications in inflammation support, respiratory health, and cardiovascular health. Together, they are an unbeatable one-two punch to maintain healthy living.*
Learn More
Bromelain
A proteolytic enzyme derived from the stem and fruit of pineapples. Pineapples have a long tradition as a medicinal plant among the natives of South and Central America. Bromelain is popularly used today for inflammation and fibrinolytic support.*
Learn More
Papain
A proteolytic enzyme derived from the papaya plant. Highly effective, generally well-tolerated by humans and animals, and enormously versatile, Papain is known for the several types of proteases active in a wide range of conditions. Papaya leaves and fruit have a long history of medicinal use in Central America and the Caribbean.*
Learn More
Lipase
A class of enzymes that help break down fats into fatty acids. Lipases are found in humans, animals, plants and microbes. The fatty acids produced by lipase are used for the body's essential functions like energy, cell function, organ protection and nutrient absorption.*
Learn More
Rutin
A bioflavonoid commonly found in plants, fruits and vegetables. Bioflavonoids are ubiquitous in plants and commonly consumed in the human diet through fruits, vegetables and herbs. Flavonoids like rutin have various biological activities and potential health benefits, including antioxidant, inflammation, cardioprotective and neuroprotective support.*
Learn More
Amla
A nutrient-rich fruit native to India and Southeast Asia. Amla is one of the richest natural sources of vitamin C, containing up to 600-700 mg per fruit, which is significantly more than oranges. Sour, bitter and astringent to taste, amla's numerous health benefits are hard to get by directly eating the fruit. Instead, it is commonly consumed pickled, candied, juiced, or as a powdered extract (like that used in supplements). Amla has been used in Ayurvedic medicine for centuries to support immune, digestive, and skin and hair health.*
Learn More
Proteases
A class of enzymes that help break down proteins into smaller peptides and amino acids. Proteases are found in humans, animals, plants and microbes. Peptides and amino acids play an essential role in digestion, tissue building, energy metabolism, immune function, and the synthesis of hormones and neurotransmitters, which influence mood regulation and cognitive functions.*
Coenzyme q10
A fat-soluble vitamin-like compound known as ubiquinone, which is naturally present in every cellular membrane in the body. Co-enzyme Q10 plays a crucial role in the mitochondrial oxidative respiratory chain, aiding in the production of ATP, which is essential for energy transfer within cells.*
Magnesium
An ionic mineral that serves as a crucial co-factor in over 600 enzymatic reactions. Magnesium helps to regulate enzyme activity by maintaining proper enzyme structure and function.*
Frequently Asked Questions
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.*
Yes! Experts know certain enzymes are delicate and susceptible to the harsh acidic conditions of the stomach. So, our researchers developed a cutting-edge delivery system to increase their efficacy: they applied a polymer called MAAC to both the serrapeptase and the nattokinase in SEBkinase®. MAAC is acid resistant, and helps protect SEBkinase® as it passes through the stomach acid. Once it reaches the basic conditions of the small intestine, the MAAC dissolves, delivering more active enzyme where it is most needed.*
No! At AST Enzymes, we use Methacrylic Acid Copolymer (MAAC) for our acid-resistant polymer, which does not use or contain phthalates. Wondering if MAAC is ok to put in your body? Don't stress. MAAC is a phthalate-free, food-grade compound used for over 50 years and deemed safe by even the most strict food safety authorities.*
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. Also remember, systemic enzymes are best absorbed on an empty stomach.*
The use of Serracor-NK® has not been shown to exhibit detrimental effects, long term or short term. Minor side effects may vary. Gastrointestinal disturbances have been reported by a small percentage of new users, but once the dosage is adjusted, tolerance is maintained. 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, particularly if you are on blood-thinning medications, or are pregnant or nursing.*
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 Serrapeptase 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 supporting the body are more attainable.*
Although digestive and systemic enzymes do not have any negative interactions in terms of ingredients, they should not 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.*
Real People, Real Reviews
Have been taking Serracor-NK for about 3 years now. Has definitely cut down on the excess fibrin and mucus. Can breathe so much better too. Will continue with this product indefinitely as it has greatly helped my breathing.
A. Bellin
I’ve been using Serracor-NK for about 7 years now. The CoQ10 is great for energy and mental acuity! I’m pretty sure it’s the effect of the fibrin metabolism that supports my vision. I am 64 and still don’t wear glasses, for reading or otherwise. The magnesium support has a nice calming effect on the nerves, I find. I may get a cold every 5-6 years, but that’s it. I found out the hard way, by forgetting to pack my Serracor-NK for a trip, exactly what benefits I’m getting from this enzyme supplement. And I don’t want to be without it again! Thank you! It’s healthy in so many ways.
Susan Tribull
Amazing supplement, I feel so much better taking it! Thanks for a great product.
I have been using Serracor for 14 years. It has worked well for my DVT condition.
I can feel the difference when I take the Serracor-NK. Works for me!
Love this product!
Thank you very much for inventing such an amazing supplement
Taking your product is a personal experiment. I have read that fibrin metabolizers are being studied as a possible retarding agent for the progressing scarring of the lungs in people with IPF & PAH. I am terminal, and hoping my experiment will grant me more time. Doesn't look like it working yet.
Great product!
It really makes a BIG difference in not needing my asthma inhaler. Especially in allergy season.
I’ve had candida problems for 30 years. All the probiotics in the world were not going fix a biofilm problem. I took 3 twice a day for 3 months and I have had zero issues. The product works!!
I have been taking Serracor N K for several years. Before that I took other enzymes from AST. They’ve been an important part of me managing my cholesterol levels. My body doesn’t process cholesterol properly and so my cardiologist wants my cholesterol level down around 100. These enzymes are an important part of me achieving this.
Feel the vessels opening up
I’ve found Serracor-NK to be a helpful part of my wellness routine, especially for supporting circulation and easing the discomfort I associate with osteoarthritis. After using it consistently, I noticed less heaviness and stiffness, and I felt more comfortable moving through the day.
What I appreciated most was the way it seemed to support both joint comfort and circulation at the same time. For me, that combination made it stand out from other supplements I’ve tried, since it felt like it was addressing more than just one issue at the same time.
I also liked that it fit well into a natural, supplement-based approach. I still pay attention to diet, hydration, and movement, but Serracor-NK felt like a meaningful addition that supported my overall results.
I would consider Serracor-NK a worthwhile option for anyone looking for a more natural approach to inflammation and vascular support.
I got a bottle of these for my mom, who is over 70 and struggles with health in general. She specifically has issues breathing. After getting on the Serracor-NK, she said she can take her usual walks without being out of breath by the end of it. So, she has definitely experienced relief even in the first week. I'm excited to see how she progresses through the bottle and onto the next one. Thanks for helping my mom feel better, that's a huge achievement!
luv ast enzymes all great n customer service great too--luv their products for sinus inflammation and many other things aches pains etc .god bless u all god luvs u all---
Great product for reducing inflammation
I have been taking since 2010. This was recommended by my doctor following open heart surgery.
I love all product. My favorite Floracor, digestive enzymes, and serracor -NK
Have purchased from other suppliers before. AST is the real deal. Noticeable difference in my energy level and overall feeling of well being. Pair this with Serracore. You will not regret.
Serracor‑NK has been a great addition to my wellness routine. I appreciate its blend of systemic enzymes and how gentle it feels on my system. Over time, I’ve noticed better overall comfort and recovery. It’s easy to take consistently and has become a supplement I genuinely value.
A family member has scaring and shortness of breath due to COVID. AST products have helped greatly.
Does a great job relieving inflammation.
I'm taking this because of my naturopath. Not sure how much it's really working, but I know it takes time.
I’ve noticed a difference right away. I feel much better in my physical body. My sleep also seems better
Seem to be working. No issues when taking.
I haven't received my order. It's being held somewhere since January 14, 2026
The tracking number is LB481563288US
My order number is 3083
I would like to tell you how much I like it, but I don't have it.
Ok. I have taken it some time ago. I have just been taking it again for a few days. I think it is doing me some good.
I’ve felt a huge difference after just 2 months of using this.
Seems to be pretty good...
So far so good. Easy to use and take. Will see what the long term results are. Company easy to work with. Shipping was timely.
Very helpful for flow and plaque removal. Feel more energy, and confidence.
All my blood levels are looking good!!!!