Oral use though will reduce DHT levels systemically, which may adversely affect training and sex drive.
For use in cycles with testosterone, I donít think it is bad at all. One simply doesnít want less DHT than normal. As the amount of testosterone in the system increases, the amount of finasteride needed to keep levels down to normal increases. I consider 5 mg/day reasonable at the gram per week level, and proportionally less at lower dosages of testosterone.
I personally wouldn't use more than the recommended pharmaceutical dosage, or 5 mg/day. More might not be safe and might at some point cause DHT levels to become abnormally low.