Lysozyme
EVIDENCE: WEAKAlso sold as: muramidase, N-acetylmuramide glycanhydrolase, hen egg-white lysozyme, HEWL
Lysozyme is an enzyme found in saliva, tears, and egg white that breaks bacterial cell walls. Human dental research is limited, including a plaque-regrowth trial finding no benefit. Egg-derived preparations matter for people with egg allergies.
Compiled by iSupplementReviews editorial team ·Updated 2026-10-06 · 4 sources
- Type
- Enzyme — innate immune protein
- Studied dose
- No supplement-dose established for oral outcomes; studied inside multi-protein rinses/tablets
- Best form
- As part of a salivary-protein blend (with lactoperoxidase, lactoferrin) — solo lysozyme products have no oral trial base
- Our rating
- WEAK — Mostly small, animal, or traditional evidence
What is lysozyme?
Lysozyme is an enzyme that breaks bacterial cell walls, found in tears, mucus, saliva, and egg white. Alexander Fleming identified it about a century ago. Commercial preparations commonly come from eggs, which matters for allergy.
Other names and forms it’s sold as
- Muramidase: its systematic name
- HEWL (hen egg-white lysozyme): the commercial source
- Salivary-protein blends: bundled with lactoperoxidase and lactoferrin in “host-protein” oral products
What is it claimed to do?
Dissolve harmful oral bacteria, support the mouth’s natural defenses, freshen breath by reducing bacterial load. Mechanism is textbook-real; product-level outcome data is the thin part.
What does the research show?
| Claim | Evidence | Dose studied | Verdict |
|---|---|---|---|
| Antibacterial mechanism | Decades of biochemistry — cell-wall dissolution is fully characterized | — | Supported (mechanism) |
| Oral benefit as part of protein rinse | 4-day plaque-regrowth trial: LLL rinse no better than saline | Multi-protein rinse | One null human trial |
| Benefits gum health | Enzyme-system dentifrice trials (lysozyme inside) showed benefit — non-isolated | Combo dentifrice | Partial — inseparable from system |
| Standalone supplement effect | No trials | — | Unproven |
Mechanism vs. mouth reality
Lysozyme’s problem in oral care isn’t the enzyme; it’s contact and context. It only kills bacteria it physically touches, it works best on gram-positive species, and plaque biofilm shields many pathogens from enzymatic reach. In lab buffer it’s lethal; in a mouth full of biofilm, saliva proteins, and brief contact windows, the kill rate shrinks, which is likely why the one controlled human rinse trial found nothing beyond saline.
What dose was studied?
| Goal | Dose | Form/route | Duration |
|---|---|---|---|
| Plaque regrowth inhibition | LPO+lysozyme+LF combination | Mouthrinse, 4-day model | 4 days |
| Enzyme-system gum benefit | Inside multi-enzyme dentifrice | Brushing 2×/day | 13–26 weeks |
Side effects
For non-allergic users, none meaningful; it’s a food protein. Egg-allergic users: lysozyme is a major egg allergen and labels frequently omit the “Contains: Egg” declaration, a real safety-labeling gap.
Drug interactions
None documented.
Who should not take it?
Egg-allergic individuals; this is the one real exclusion, and it applies whether or not the label prints the allergen warning. Everyone else: no established concerns.
What the authorities say
Unassessed for oral claims; GRAS-ish status as a food enzyme (it’s used in cheese production as a preservative). Claims unverified by institutions.
What to know about lysozyme
Lysozyme’s mechanism is established, but oral supplement evidence is limited. It may be part of a combined saliva-enzyme system; that does not prove an isolated benefit. People with egg allergies need the source confirmed before considering it.
Frequently asked questions about Lysozyme
What does lysozyme do in the mouth?
It's a front-line innate-immune enzyme: it cleaves the cell wall of bacteria, especially gram-positive species, dissolving them on contact. Your saliva already contains it; supplement logic is topping up an existing defense protein at the surfaces it normally guards.
Is there human evidence for lysozyme in oral care?
Thin and mixed: salivary-lysozyme function is well characterized (it's one of saliva's major antimicrobial proteins), and it's been studied inside multi-protein products, but a 4-day plaque-regrowth trial found a lysozyme+lactoperoxidase+lactoferrin rinse no better than saline. Real mechanism, unproven standalone benefit.
Is lysozyme an allergen?
Yes. Commercial lysozyme is extracted from egg white and is one of the major egg allergens. Egg-allergic users should treat lysozyme-containing supplements as egg-derived, and note that some dental-product labels carrying lysozyme print no egg 'Contains' declaration.
Does a lysozyme tablet reach the mouth intact?
It's a protein; much is digested on swallowing, which is why hold-in-mouth/chewable formats are the sensible delivery for a salivary enzyme. The contact fraction during the chew is the part that could matter.
Is lysozyme safe?
For non-allergic users, extremely; you swallow it in every bite of egg-containing food and make it in your own secretions. The only real flag is egg allergy.
References
- [1]Antimicrobial host-protein rinse (LPO+lysozyme+LF) vs plaque regrowth — observer-masked RCT, no benefit over saline (J Periodontol 2004)
- [2]Clinical applications of antimicrobial host proteins (LPO, lysozyme, LF) in xerostomia — Tenovuo (Arch Oral Biol 2002)
- [3]Lactoperoxidase system and salivary antimicrobial proteins — review (Int J Mol Sci 2019)
- [4]Hen egg-white lysozyme — allergen review (Clin Exp Allergy)
Products we reviewed containing Lysozyme
Based on recorded labels or seller-described formulas. Inclusion does not establish a match to the strains, preparations or amounts studied here; check each review's disclosure limits.