Having just gone for about a 15 minute walk outdoors, I can say with fair certainty that cetirizine HCl is helping with my allergies. I'm definitely feeling a strong tingling in my nose like I'm on the verge of a sneezing fit, but I'm pretty sure that undrugged I'd be in the midst of a full-on attack that would have me sneezing and blowing my nose on and off all day.