23 year old male using finasteride for almost 2-3 weeks now. Can I use Cialis to improve my sexual functions?

So I've been on finasteride for a few weeks now. I notice when I masturbate, it's more difficult to get erect and stay erect. If I stop for a few seconds, the erection slowly dies down. And when I ejaculate, it seems a little watery and a lesser amount than prior to finasteride use. I know these are normal side effects with finasteride but can i take Cialis to help me? A friend recommended it.