Generic Zyrtec is used to prevent or treat symptoms of hay fever and to treat cold or allergy symptoms such as sneezing, itching, watery eyes, or runny nose. It is also used to treat itching and swelling caused by chronic urticaria (hives). More info »
Generic Zyrtec-D Extended Release is an antihistamine and decongestant combination which provides relief of seasonal and perennial allergy symptoms such as watery eyes, runny nose, itching eyes, sneezing, and stuffy nose (nasal congestion). More info »
Regarding the effect: I do notice an increase in bloodflow and a better
stamina using the pills (I use 50mg). A side-effect I have noticed is that
my nose clogs up so I seem like I have a cold for an hour or so after taking
one pill. No other side-effects than that.