Generic Dilantin is used for treating tonic-clonic (grand mal) and partial seizures. It is also used to prevent and treat seizures that may occur during or after brain or nervous system surgery. 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.