Some supplement marketing claims nattokinase can help dissolve uterine fibroids, break down keloid scars, or reduce fibrous breast tissue, framing the enzyme’s clot-dissolving activity as a general fibrosis fix. Fibroids and keloids are, in fact, both fibroproliferative conditions with real biological similarities. But similarity between two conditions is not the same as evidence that a supplement treats either one. Here is what the research actually establishes, and where the marketing claims outrun it.
Key Takeaways
- Peer-reviewed research does establish that keloids and uterine fibroids are biologically related fibroproliferative conditions, with some population studies finding people with one have an elevated risk of the other.
- No published clinical trial has tested nattokinase as a treatment for uterine fibroids or keloid scars in humans.
- Marketing claims that nattokinase dissolves fibroids or fibrous tissue extrapolate from its established fibrin-clot-dissolving activity in blood vessels, which is a mechanistically different process than reducing fibrotic collagen deposits in fibroid or keloid tissue.
- Uterine fibroids and keloids share genetic and extracellular-matrix characteristics with each other, but neither condition’s abnormal tissue growth is primarily a fibrin-clot problem, which is what nattokinase’s fibrinolytic enzyme activity specifically targets.
- Anyone considering nattokinase for either condition should treat it as unproven and discuss it with a physician rather than as a substitute for established fibroid or keloid treatment options.
This post contains affiliate links. As an Amazon Associate, NattokinaseHub earns from qualifying purchases at no extra cost to you.
The Real Fibroid-Keloid Connection (and Why It Is Not About Nattokinase)
The genuine research link here has nothing to do with nattokinase. A bidirectional Mendelian randomization study using European population genetic data found that uterine fibroids significantly raised the odds of developing keloids and hypertrophic scars. A separate physiological review noted that women with fibroids in some populations show a more than two-fold increased risk of keloids, and proposed that the two conditions may share genetic risk factors tied to abnormal wound-healing and extracellular matrix formation. This is legitimate, peer-reviewed evidence that fibroids and keloids are related fibroproliferative diseases. It says nothing about whether any supplement, including nattokinase, affects either condition.
Where the Marketing Claim Comes From
Nattokinase’s fibrinolytic activity, its ability to break down fibrin, the mesh-like protein structure that forms blood clots, has been shown in lab clot-lysis tests, which is not the same as an effect on clots or disease in people [2][3].[1] Some supplement marketing extends this mechanism by analogy: if nattokinase dissolves fibrin clots, the reasoning goes, it should also dissolve other fibrous tissue, including fibroids, keloids, and scar tissue. This is a mechanistic leap that has not been validated in controlled research. Fibrin clots in blood vessels and the collagen-rich fibrotic tissue that makes up a uterine fibroid or a keloid scar are different biological structures, formed through different processes, and there is no published clinical trial demonstrating that nattokinase’s fibrin-targeting enzymatic activity meaningfully breaks down either one.
Research note: In a lab model of amyloid microclots from plasma, nattokinase on its own did not significantly shrink the clots, and adding it to ultrasound added little [6].
What Actually Treats Uterine Fibroids
Uterine fibroids are managed through established medical approaches depending on size, symptoms, and a patient’s fertility goals: watchful waiting for asymptomatic small fibroids, hormonal medications such as GnRH agonists or progestin-releasing IUDs to manage symptoms, uterine fibroid embolization, myomectomy, or hysterectomy for larger or more symptomatic cases. None of these evidence-based approaches involve fibrinolytic enzyme supplementation, and no gynecological guideline recommends nattokinase as a fibroid treatment.
The closest lab signal is a mouse study in which nattokinase injected directly into tumours degraded fibronectin in the tumour matrix and reduced tumour stiffness. That was an injection into tumours, not oral use, and it says nothing about fibroids or keloids. Cell experiments also found nattokinase degrading a housekeeping protein, which the authors read as low protease specificity [4][5].
What Actually Treats Keloid Scars
Keloid management similarly relies on established dermatological approaches: intralesional corticosteroid injections, silicone gel sheeting, pressure therapy, cryotherapy, laser treatment, or surgical excision (often combined with adjuvant therapy to reduce recurrence, since keloids can regrow after excision alone). As with fibroids, no dermatology guideline includes nattokinase as a keloid treatment, and no controlled trial has tested it for this purpose.
The Honest Bottom Line
It is accurate to say fibroids and keloids are related fibrotic conditions. It is not accurate, based on current evidence, to say nattokinase treats either one. If a product description or article claims nattokinase dissolves fibroids or fibrous tissue and cites no clinical trial, treat that claim with the same skepticism you would apply to any unproven health claim, and do not substitute it for medical evaluation of a suspected fibroid or a growing scar.
Frequently Asked Questions
Can nattokinase shrink or dissolve uterine fibroids?
There is no published clinical trial testing this. The claim extrapolates from nattokinase’s blood-clot-dissolving activity, which is a different biological process than fibroid tissue formation. Anyone with a suspected fibroid should be evaluated by a gynecologist.
Does nattokinase reduce keloid scars?
No controlled human study has tested nattokinase for keloid treatment. Established keloid treatments include corticosteroid injections, silicone sheeting, and other dermatologist-directed therapies.
Are fibroids and keloids actually related conditions?
Yes, peer-reviewed research, including a Mendelian randomization study, has found a real association between the two as fibroproliferative diseases sharing genetic and tissue-level characteristics. This finding is unrelated to any supplement and does not imply nattokinase affects either condition.
These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease. If you have a diagnosed or suspected fibroid or keloid, consult the appropriate specialist rather than relying on supplement marketing claims.
References
- Nattokinase: An Oral Antithrombotic Agent for the Prevention of Cardiovascular Disease. International Journal of Molecular Sciences (2017). PMID 28264497
- Tetsumei Urano et al. The Profibrinolytic Enzyme Subtilisin NAT Purified fromBacillus subtilis Cleaves and Inactivates Plasminogen Activator Inhibitor Type 1. Journal of Biological Chemistry (2001). PMID 11325965
- Pinontoan R et al. Fibrinolytic characteristics of Bacillus subtilis G8 isolated from natto. Bioscience of microbiota, food and health (2021). PMID 34285859
- Zhang Y et al. Nattokinase-Mediated Regulation of Tumor Physical Microenvironment to Enhance Chemotherapy, Radiotherapy, and CAR-T Therapy of Solid Tumor. ACS nano (2023). PMID 37057972
- Tanikawa T et al. Degradative Effect of Nattokinase on Spike Protein of SARS-CoV-2. Molecules (Basel, Switzerland) (2022). PMID 36080170
- Rasouli R et al. Investigation of the synergistic effect of enzymatic and Ultrasound-Induced amyloid microclot degradation. Journal of thrombosis and thrombolysis (2026). PMID 41405757
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease. Content is for informational purposes only and is not medical advice; consult a qualified healthcare provider before starting any supplement. As an Amazon Associate we earn from qualifying purchases.
