Yes, I get slightly drowsy from Zyrtec. Benadryl will knock me out for 2 days so I think I'm very sensitive to antihistamines.

I was taking zyrtec regularly for awhile and noticed that I was having a lot of heart palpitations. When I stopped taking it, things went back to normal.

Interesting, I haven’t noticed this side effect, and I’m pretty sensitive to a lot of meds (can’t do Benadryl or most cold medicines because I feel really loopy and unable to function). I take Zyrtec off and on pretty regularly.

Yes, as does Benadryl. Allegra and Claritin do not.

Meant to say can’t do Benadryl.

No I love it. I can do Benadryl.

I had to take it for a few years and in retrospect was drowsy all the time.

Yes it’s a side effect for sure.

Try Allegra.

Yes, it's well-known that Zyrtec is the anti-histamine that makes people sleepy. It's also very effective, but some people need to take it for a week before getting used to the drowzy effect. When I was a teenager and other histamines didn't exist, I had to wait 2 weeks for the drowziness to go away. I took Zyrtec for the entire spring due to severe pollen allergies.

If you need a temporary allergy relief, that doesn't make you drowsy, I suggest Aleve D. It perks me right up and clears my sinuses.

It's not for daily use though, so keep that in mind.

Yes, Zyrtec makes me feel weird for a whole day. Not worth it.

Yes, I sleep amazing with Zyrtec but also sluggish during the day. Apparently you develop a tolerance after a while if you take it regularly but I only take it when I visit houses with cats.

Not at all. Far better for me than other options.

Not me, but my DH says allergy meds make him really drowsy.

I don’t usually take Zyrtec but did last night as my eyes were itchy.
Boy this morning I feel drowsy and light headed - not myself.
Could Zyrtec cause this?

Btw my kids’ pedi docs always recommend Zyrtec over any other daily allergy med, so I give it to them frequently for seasonal allergies.