Propecia (finasteride) for baldness is the same drug used to treat benign prostatic hyperplasia (BPH), although the brand name for BPH treatment is Proscar. Men who take finasteride for male pattern baldness are prescribed a 1-mg dose, while men with BPH are typically given a prescription for 5 mg.
Male pattern baldness accounts for more than 95 percent of hair loss among men. Two thirds of American men experience noticeable hair loss by age 35, and that percentage jumps to about 85 percent by age 50.
Regardless of the dosage, finasteride is associated with side effects. In fact, the Food and Drug Administration (FDA) has issued warnings regarding finasteride and ordered the drug makers to put labels on their products regarding the sexual side effects associated with use of the drug. Therefore, if you take Propecia (finasteride) for male pattern baldness, you should know there is a chance you will experience libido disorders, ejaculation problems, orgasm problems, erectile dysfunction, male infertility, and/or poor quality sperm. The rest of the bad news is that these side effects—except for the last two–do not resolve themselves after you stop taking finasteride.
Given the possibility of serious ongoing side effects associated with the use of Propecia (finasteride) for baldness, you should discuss other options with your physician. One possible alternative, which is still in the development and trial stages, is a topical form of finasteride that has been developed and is being tested. The new form of medication will be delivered via nanoparticles (a mean particle size of about 300 nanometers), which will reach the dermis and hair follicles and may be associated with fewer and/or milder side effects. For now, however, the only form of finasteride for baldness is an oral formulation.
Reference
Roque LV et al. Design of finasteride-loaded nanoparticles for potential treatment of alopecia. Skin Pharmacology and Physiology 2017; 30(4): 197-204