Pirinase allergy nasal spray works to help relieve allergy symptoms for up to 24 hours help prevent the return of symptoms during the day pirinase allergy nasal spray protects from all major airborne allergies including pollen hayfever pet hair dust mites mould spores pirinase allergy nasal spray has a direct action to relieve allergy symptoms where they start you can use it in advance to prevent symptoms if you know you are going to come into contact with anything that may trigger you