Egg Yolk Immunoglobulin (IgY)

IgY · Egg yolk immunoglobulin · Immunoglobulin Y · Hyperimmune egg

Snapshot

Indications	Contraindications
H. pylori infection¹ Rotavirus diarrhea in children² Streptococcus mutans reduction³ Chronic periodontitis^3–5 Pseudomonas in cystic fibrosis⁶	Egg allergy⁷

Immunoglobulin Y (IgY) is the antibody class found in the yolk of eggs from hens immunized against a target pathogen or antigen.⁸ Taken orally or applied locally, it binds the target at the mucosal surface, a form of passive immunization, and is used for gastrointestinal, oral, and respiratory-tract infections⁸. Uses with trial data include Helicobacter pylori infection as an adjunct to standard therapy, rotavirus diarrhea in children, and periodontitis and dental caries⁸. It has been tested for preventing Pseudomonas aeruginosa colonization in cystic fibrosis; an early feasibility study of daily gargling delayed recolonization, but larger trials are needed⁶.

The evidence is mixed by use.^{1, 9} A 2024 systematic review found three of four IgY studies supportive for H. pylori eradication¹, yet a 2026 randomized trial of an adjunct to triple therapy found an eradication difference that was not statistically significant⁹. In children with rotavirus diarrhea, placebo-controlled trials found earlier clearance of rotavirus from stool^{2, 10}. A meta-analysis of oral trials found reduced Streptococcus mutans but no benefit on periodontal probing depth³. A trial has used egg yolk immunoglobulin as a mouthwash with subgingival irrigation; see Form comparison¹¹.

The most consequential caution is allergy to the source material.⁷ United States product labels warn against use by individuals with egg allergies, and all 27 labels sampled carry this warning⁷. The same labels ask those taking medication to discuss potential interactions with a healthcare professional⁷.

Last updated October 17, 2026. Read how we make monographs.

In the full monograph

34 sources, 31 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources