Hi Sir, I Am 26 Year Old And Facing Middle

Hi Sir,
I am 26 year old and facing middle level hair loss, and my doctor has advised me to take Morr F 5% for a month, and after that Morr F 2% for next month,

I have read the user guide provided with solution and i am concern about the sexual side effect which mentioned there.
Could you please help me with this.

And also what is difference between Topical and Oral Finasteride solution?