Most of the time when you don’t get hard after taking Finasteride, an adverse reaction has occurred, and it is recommended that the patient go to the hospital in time to stop or change the medication under the guidance of the doctor. As a 5α-reductase inhibitor, Finasteride is often used to treat symptomatic BPH. Finasteride is well tolerated and adverse effects are mild and transient, including impotence, decreased libido, and ejaculatory disorders. If a patient develops erectile dysfunction after taking finasteride, the drug needs to be discontinued or changed. In general, the adverse effects will slowly disappear after stopping the drug. Finasteride should be used under the guidance of a medical professional and is contraindicated in people who are allergic to finasteride, pregnant and women who may become pregnant.