I only gave this a 4 so people don't think everyone's experience is unrealistically 100% effectiveness. I gave my bottle to a friend who has dog allergies. Gets hives everywhere a dog licks them, on allergy meds daily, still has 7 German shepherds. With every other day room spraying, dog bed spraying, air spraying, they did not notice a difference. I took it with me to pet sit with 4 different mixed breed dogs. My dog allergies are mild. Cat allergies much worse for me. Anyway, my sinuses were stuffed up and I had a slight headache there. I sprayed the spray in living room and guest room, throughout the air. In the evening and overnight to the next day my sinuses were clear and headache gone. So I think it's really worth a try if you need it! But be open that it might not do everything you need it to.