Serrapeptase: What the Evidence Shows and Who Should Skip It

Serrapeptase is a protein-digesting enzyme made by bacteria first found in the silkworm gut, and it is sold as a supplement for swelling, pain and “healthy inflammation response.” The human evidence is thin: a systematic review called the existing trials poor quality, the drug version was withdrawn in Japan in 2011 after it failed to beat placebo, and the enzyme may raise bleeding concerns with blood thinners. Below is what serrapeptase is, what the studies actually tested, how it compares with nattokinase and who should talk to a clinician first.

Peptide Labs does not sell serrapeptase, so no product is recommended here. This article is general information, not medical advice.

What is serrapeptase?

Serrapeptase, also spelled serratiopeptidase in research papers, is a protease: an enzyme that breaks proteins apart. It is produced by the bacterium Serratia marcescens, which was originally isolated from the gut of silkworms. Chemically, researchers describe it as a zinc-containing enzyme. Because some Serratia strains can cause infections, labs have also worked on producing the enzyme through cloning rather than growing the original bacterium.

For years, doctors in Japan, India and other countries prescribed serrapeptase after surgery and in dentistry, ear, nose and throat care, orthopedics and gynecology, hoping to reduce swelling. In the United States it is sold as a dietary supplement, which means the FDA has not reviewed it for safety or effectiveness before it reached shelves.

Does it survive digestion?

This is an open question. Serrapeptase is itself a protein, and a 2024 review on delivery notes that it is vulnerable to being broken down in the digestive tract, with stability and absorption listed as common problems. Some labels describe delayed-release or acid-resistant capsules for this reason, but how much active enzyme reaches the bloodstream in people has not been well measured.

Serrapeptase benefits: what the research shows

Most serrapeptase research comes from small trials after dental or minor surgery. When reviewers have pooled the evidence, the picture is weak and mixed.

The 2013 review, by pharmacologists in New Delhi, searched the literature and graded every study it could find. It concluded that the evidence for serrapeptase as an anti-inflammatory and pain reliever rests on studies of poor methodology, that many did not define their outcomes clearly and that data on long-term safety were lacking. It specifically said the evidence did not support promoting it as a health supplement for heart or artery health, a claim still common in marketing.

Why Japan withdrew the drug

In Japan, serrapeptase was sold for years as a prescription anti-inflammatory tablet. In February 2011 the maker, Takeda, voluntarily withdrew it after newer placebo-controlled studies found no statistically significant benefit. Singapore’s Health Sciences Authority then reviewed the evidence and decided in November 2011 to phase it out as a medicine, saying there was no substantive scientific evidence to support that status. The agency noted a long history of use with minimal safety concerns and still allows the enzyme as a health supplement ingredient.

Serrapeptase side effects and safety

Side effects have not been studied carefully, which is different from saying there are none. WebMD’s monograph lists severe allergic reactions and rare serious skin reactions, including Stevens-Johnson syndrome and bullous pemphigoid, that may need hospital care. Published case reports from Japan describe eosinophilic pneumonia, a type of lung inflammation, in an 84-year-old man and a 32-year-old woman after serrapeptase use. Dental surgeons in India reported a facial abscess that spread into deeper tissue after the enzyme was given and advised against it when an abscess is present.

Talk to a clinician before using serrapeptase, and do not use it on your own, if any of these apply:

• You take warfarin or another blood thinner, an antiplatelet drug such as aspirin or clopidogrel, or regular NSAIDs. The enzyme breaks down fibrin in lab tests, and interactions are not fully understood.
• You have a bleeding disorder or have surgery or dental work coming up.
• You have an active or recurring infection, or an eosinophilic condition.
• You are pregnant or breastfeeding; it is not known how serrapeptase affects pregnancy or whether it passes into breast milk.
• You have new or unexplained pain, swelling or shortness of breath. Those need a diagnosis, not an enzyme.

If you take other supplements with possible blood-thinning effects, such as fish oil, ginkgo, garlic or high-strength turmeric, the cautions add up. Our guide to turmeric and black pepper explains a similar interaction question.

Serrapeptase vs nattokinase

The two enzymes are often sold together or compared online. Both come from bacteria and both break down fibrin in the lab, which is the root of the shared bleeding caution. They differ in source and in the questions researchers have asked about them.

Read our nattokinase guide for its own trials and case reports. Neither enzyme should replace a prescribed blood thinner, and combining them stacks the same concern.

How serrapeptase differs from enzymes for meals

Serrapeptase is marketed as a “systemic” enzyme, meant to act beyond the gut, while products such as lactase or pancreatic-type blends are meant to work on food in the digestive tract. Pineapple-derived bromelain sits in between, sold both ways. If your goal is easier digestion of meals, see our guides to digestive enzymes and bromelain. Combination products sometimes add quercetin or turmeric, which brings their own interaction questions.

How to read a serrapeptase label

1. Check how activity is listed. Labels usually give enzyme activity units rather than weight, and units are not standardized across brands, so products are hard to compare.
2. Look at the capsule type. Delayed-release capsules are a design choice, not proof of absorption.
3. Read the full ingredient list for added nattokinase, bromelain or herbs that change the safety picture.
4. Read claims about arteries, sinuses or “dissolving” tissue as marketing; the FDA has not evaluated them.
5. Look for independent testing, explained in our guide to third-party tested supplements.

Frequently Asked Questions

Questions about a label? Contact us or read our Buyer’s Guide. Follow the label and ask a healthcare provider before starting any supplement, especially if you take medicines. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Last reviewed October 2026.

Related guides: Nattokinase: Benefits, Side Effects and Bleeding Risks, Bromelain: Benefits, Evidence, Papain and Safety, Turmeric Side Effects: Liver Injury, Interactions and Turmeric vs Curcumin.