Finasteride is only prescribed for men, it should never be used by women. Small quantities of it can also pass into semen, so if you’re having sex with your partner, you should always wear a condom if you’re taking it.
Women should also be careful not to touch any crushed or broken tablets if there’s any possibility that they may be pregnant, as they can get into the bloodstream. Finasteride tablets have a protective coating on them to help guard against this.