Taking finasteride is usually more than three months to see the effect, the maintenance time should be at least six months, if the continuous use of twelve months, the effect is not obvious, and serious adverse reactions, it is recommended to stop the drug. Finasteride has antagonism within the androgenic effect, can make the prostate size, increase the rate of urinary flow, prevention of benign prostatic hyperplasia, generally used for the treatment of prostatic hyperplasia, may appear rash, nausea, vomiting reaction, may also appear erectile dysfunction, decreased libido, ejaculation volume reduction and other reactions, generally take more than three months to see the effect. People who are allergic to Finasteride can not take it, women during pregnancy, children can not take it, the specific use of the need to be under the guidance of a doctor to take the correct.