Do pillow protectors really stop dust mites and allergens?

Zippered encasement-style protectors are the type most associated with dust-mite and allergen blocking, and several picks here advertise tightly woven or membrane-backed barriers plus OEKO-TEX certification. Verified-purchase reviewers broadly report fewer allergy flare-ups, but because we found no independent lab data in this pool, treat allergen claims as marketing-supported rather than test-verified.