5 Alpha Reductase
5 Alpha Reductase is a category of drugs that shrink the prostate, typically taking 4 to 6 months to maximal effect. Some examples include: Finasteride (Proscar), Dutasteride (Avodart). Although they take longer to work, the inhibitors are useful in very large prostate diagnoses. It may cause erectile dysfunction, reduced volume of semen, and breast tenderness or enlargement.