I turned to Children's Zyrtec for my two little girls (ages three and four) after my doctor prescribed a Rx that was SUPER expensive even with insurance. On a side note: my doctor did give the okay to give Zyrtec to my children. Initially I was giving them 1/2 a dose twice daily...but then quickly learned how sleepy it made them so I opted to only give it to them at night. Night's with Zyrtec are pure bliss....they sleep ALL NIGHT!!! It also keeps them from getting that post nasal drip associated with allergies and sleeping at night. On rare occasion the Zyrtec will wear off before the 24 hours is up...but that is when the allergies are super severe. But most of the time I can count on Children's Zyrtec to last the full 24 hours. Without it my girls would have buckets of running snot running down their poor little faces. They don't LOVE the taste, but I always bribe them to take it. If they take it I give them their gummy vitamin...works every time!