Finasteride is a prescription drug used to prevent or stop hair loss. Finasteride is to be used only by men. Women should not take finasteride.
Finasteride should be kept out of reach of children and should not be used in case you are trying to get pregnant. If pregnant women comes in contact with finasteride the contact area should be immediately washed off. If a pregnant woman takes finasteride, there will be serious irreversible consequences for the new born kid. Hence, it is advisable to not use finasteride for couples trying to get pregnant.
Although, there is a low probability of having a sexual side effect from finasteride, you should be cautious while using it and in case you are facing any side effect that is affecting your normal life, please talk to the doctor or discontinue taking the medication.