Antihistamine-free.Cortisone free.Preservatives-free.Does not cause drowsinessNo rebound effects. The natural origin formula of Puressentiel Respiratory Protective Nasal Spray combines seawater and organic essential oil of Eucalyptus radiata to moisturise and protect your nasal cavity. Seawater is a natural source of minerals and trace elements that help to maintain the natural balance of the nasal mucous membrane. Eucalyptus essential oil is known for its decongestant properties, which help to reduce nasal congestion.