The Patient's Guide to Hair Restoration - New Hair Institute

Finasteride causes an approximate 1/3 decrease in serum PSA (prostate
specific antigen) in normal men. It may also blunt the rise of PSA levels in
patients with prostate enlargement and in patients who have developed prostate
cancer. Since PSA is used to screen for prostate cancer, there is concern that
the use of Propecia may interfere with the detection of this disease. It is
important that you make your personal physician aware that you are taking
finasteride so that he or she can take into account any effects that finasteride
may have on your PSA.
There has been one small study that suggested that finasteride at 5-mg
may increase the risk of prostatic carcinoma in older patients who have an
already significantly elevated PSA. However, the methodology of this study has
been seriously questioned and data from other studies do not support its
conclusion.
Teratogenecity in Women
Finasteride should not be taken by women of childbearing age as birth
defects in male offspring can occur if significant amounts of the drug are
absorbed during fetal development. Pregnant women are warned not to handle
crushed tablets, as the drug may harm the male fetus. However, to our
knowledge, there has not been a single reported case of birth defects caused by
women handling broken or crushed finasteride tablets. The concern over
handling crushed tablets may stem from the FDA policy, which assumes
maximum absorption of the medication during any contact.
There is no evidence that exposure of pregnant women to finasteride via
semen is a risk to the fetus. For those patients who wish to limit any potential
contact of Finasteride, a condom can be worn during intercourse with a pregnant
partner.
Use in Post-Menopausal Women
A recent study was conducted to evaluate the efficacy of finasteride in
post-menopausal women. After one year of use, there was no increased hair
growth and the progression of thinning was not slowed. It is possible that the
low DHT levels observed in post-menopausal women are responsible for the lack
of significant response to finasteride, or that hair loss in this group is not related
to androgens as all. The safety profile for the use of finasteride in postmenopausal
women has not yet been established.
Long-Term Benefits and Risks
The effects of finasteride are confined to areas of the scalp that are
thinning, but where there is still some hair present. Finasteride does not seem to
grow hair in completely bald areas. Therefore, the major benefit of finasteride
seems to be in its ability to slow down or halt hair loss, or re-grow hair in parts of
the scalp where the hair is thin. The long-term ability of finasteride to maintain
one’s hair is unknown. Results generally peak at one to two years and then
decrease slightly after that.
The benefits of finasteride will stop if the medication is discontinued. Over
the 2-6 months following discontinuation, the hair loss pattern will generally
return to where it would have been if the medication had never been used.