Both are effective for regrowing hair but each has negative side effects. Minoxidil leaves your scalp very itchy with lots of dandruff. Propecia can result in depression and irreversible sexual side effects. That's right, irreversible!
There's a new product that uses minoxidil plus a lot of vitamins, nutrients, and moisturizers so your scalp won't itch. It's called Scalp Med.