Benefits
Tooth surface stain removal toothpaste 8-week RCT
In adults with extrinsic tooth staining, lysozyme toothpaste was effective at removing extrinsic stains from the tooth surface versus control. That was a toothpaste trial, brushed on and spat out, so it says nothing about swallowing lysozyme, and a 2025 systematic review of enzyme and protein toothpastes reported that the hypothesised effect against extrinsic black stains was not substantiated in the three studies it was able to include.
Gingival inflammation reduction CELC RCT (KCT0001366)
In a multicenter randomized double-blind placebo-controlled trial in chronic periodontitis, a vitamin C + E + lysozyme + carbazochrome combination (IGATAN F®) showed about 2.5x greater gingival-index improvement versus control (P=0.022). Several limits matter here. Lysozyme was one of four actives in the tablet, so its individual contribution cannot be separated out, and the participants were patients with diagnosed chronic periodontitis who had also received scaling and root planing, not general consumers. The placebo comparison ran for only the first 4 of the 8 weeks, after which both groups received the active tablet, and plaque index, probing depth, clinical attachment level and the patient-rated visual analogue score did not differ between groups.
Multi-enzyme lozenge plaque control 7-day RCT
In a small pilot in healthy adults, a multi-enzyme lozenge taken three times daily (including lysozyme) reduced new plaque build-up after one day, but that difference was gone by day 7 and the gingival index did not differ from placebo at any point. All 24 subjects completed with no adverse events. The trial was funded by the enzyme manufacturer, which has filed a patent relating to the work, and the published summary describes plaque-matrix degrading enzymes without naming lysozyme, so lysozyme's role in the lozenge is an assumption rather than something the trial measured.
Peptidoglycan hydrolysis mechanism
Lysozyme hydrolyzes the linkage between N-acetylmuramic acid + N-acetylglucosamine of peptidoglycan in cell wall of gram-positive bacteria — effectively limiting growth. This is a biochemical mechanism established in the laboratory, not a benefit measured in people. The same review notes that bacteria defend against it by producing lysozyme inhibitors or modifying their peptidoglycan, and that cell-killing activity against gram-negative bacteria has not been proved.
Toothpaste enzyme + protein synergy (13-week)
A toothpaste combining a three-enzyme system (amyloglucosidase + glucose oxidase + lactoperoxidase) with lysozyme and lactoferrin showed significant plaque and gingival benefit versus a commercial control, with plaque and gingival scores falling in the test group while rising in the control group. Nothing in this result is attributable to lysozyme on its own. The product was tested as a single finished toothpaste against a control toothpaste, so the result belongs to the whole five-component formulation, and neither trial summary isolates lysozyme or names it. Both trials of this toothpaste were run with authors employed by the manufacturer, so they are the same product tested twice for one sponsor rather than independent replication, and the route is brushing and spitting rather than swallowing.
In vivo salivary defense enhancement
mechanism — toothpaste containing enzymes + proteins enhances salivary defenses by increasing in vivo levels of antimicrobial compounds lysozyme + hydrogen peroxide. This is not well supported for lysozyme specifically. An in situ study that measured enzyme activity in the tooth pellicle after brushing with enzyme toothpastes found that peroxidase activity rose considerably and glucose oxidase rose sharply but briefly, whereas targeted accumulation of lysozyme was not pronounced, so the lysozyme half of this claim runs against the measurement.
Lysozyme + LPO synergy (Streptococcus mutans inhibition)
Lysozyme enhances the inhibitory effect of the peroxidase system on glucose metabolism of Streptococcus mutans. This comes from a 1992 test-tube experiment, not from people. In that work human milk lysozyme on its own slightly increased rather than decreased glucose uptake by Streptococcus mutans, only the combination with the peroxidase system shut glucose uptake down, and the viability of the bacteria was not affected by any of the treatments.
Mechanism of action
Peptidoglycan hydrolysis (gram-positive cell wall)
Hydrolyzes N-acetylmuramic acid + N-acetylglucosamine linkage of peptidoglycan — disrupts gram-positive bacterial cell wall integrity. Foundational antimicrobial mechanism.
Lysozyme + LPO antimicrobial synergy
Synergistic with lactoperoxidase against S. mutans. Mechanism: combined peptidoglycan plus hypothiocyanite attack on cariogenic bacteria.
Salivary defense system component
Natural human saliva contains lysozyme — endogenous antimicrobial defense. Products designed to top this up are applied inside the mouth as toothpastes, gels, rinses and chewing gums and are then spat out or swallowed only incidentally, and the clinical review behind this idea covers dry-mouth patients specifically. That is a mouth-surface route rather than a swallowed one.
Plaque-matrix degradation (non-biocidal)
Multi-enzyme lozenge mechanism — degrades plaque matrix without biocidal activity. This mechanism belongs to the lozenge as a whole rather than to lysozyme. Lysozyme cuts bacterial cell wall peptidoglycan, not the sugar polymers that make up the plaque matrix, and the lozenge trial summary does not name lysozyme among its enzymes. In that trial bacterial richness rose in both groups over the week, with the lozenge only slowing that rise in saliva, so preserving microbiome diversity is not what was shown.
Anti-inflammatory effects (gingival)
This is a proposed explanation rather than a measured one. The gingival-index improvement it refers to came from a four-ingredient tablet that also contained vitamin C, vitamin E and carbazochrome, and in that same trial plaque index did not differ from placebo, so the plaque-degradation half of the explanation was not borne out.
Tooth stain removal mechanism
Extrinsic stain removal, proposed to work through plaque and pellicle degradation and bacterial removal, although the mechanism has not been demonstrated directly and a 2025 systematic review of enzyme and protein toothpastes did not substantiate an effect against extrinsic black stains.
Clinical trials
Randomized parallel-controlled double-blind clinical trial.
70 adults with extrinsic tooth staining. Lysozyme toothpaste vs control for 8 weeks.
The Lobene stain index was significantly lower in the lysozyme toothpaste group than in the control group at both 4 and 8 weeks, with no obvious side effects and 69 of the 70 participants completing. This is the one trial on this page that tested a product actually built around lysozyme, but it is a single small trial of a toothpaste that is brushed on and spat out, and a later systematic review of enzyme and protein toothpastes did not substantiate an effect against extrinsic black stains.
Multicenter randomized double-blind placebo-controlled trial (KCT0001366, retrospectively registered Jan 2015). Approved by IRB at Kyung Hee University Dental Hospital + Yonsei University Hospital + Dankook University Hospital.
Chronic periodontitis patients. Stratified block randomization. 100 patients randomised 1:1 to CELC (vitamin C plus vitamin E plus lysozyme plus carbazochrome, the Korean product IGATAN F from Myung-In, a fixed-dose tablet taken by mouth) or placebo for the first 4 weeks only, after which both groups received CELC for the remaining 4 weeks. All patients had also received scaling and root planing first. 93 completed. GEE model adjusted for age, gender, visits.
Test group showed 2.5× GI (Gingival Index) improvement vs control (P=0.022). Significant reduction in gingival inflammation. Other parameters similar between groups. Foundational chronic periodontitis evidence with fixed-dose combination including lysozyme.
Randomized controlled pilot trial (ScienceDirect S0300571224002768 2024).
24 healthy adults randomized to Active (n=12) or Placebo (n=12). 1 lozenge TID for 7 days; no oral hygiene procedures allowed. TM-QHPI plaque index + Gingival Index + 16S rRNA gene sequencing of plaque + saliva at baseline + 7 days.
All 24 subjects completed study; NO adverse events. Plaque index was significantly lower in the active group after 1 day, but the groups no longer differed at 7 days, and the gingival index did not differ between groups. The study was funded by the enzyme manufacturer Novozymes, which has filed a related patent, and the published summary names plaque-matrix degrading enzymes without listing lysozyme, so this is weak and indirect support for lysozyme.