Can a man taking Finasteride (Propecia) contaminate his partner if he does not use a condom ?
There is no report of a case where a baby would be born with anomalies linked to the contamination of a woman by a partner taking Propecia. However, the Merck company, to be careful, recommends men taking Propecia to use a condom. While most of the doctors consider there is no risk, the most careful ones, as far as they are concerned, recommend to stop taking Propecia during the partner’s reproductive period. Here is the text written by Merck: http://www.merck.com/product/usa/pi_circulars/p/propecia/propecia_pi.pdf.
The calculation shows that even if we consider the highest level of testosterone in the sperm as well as the full absorption of this quantity by the pregnant woman, the received dose would still be 750 times lower than the dose which causes an anomaly by the rhesus monkey..
For more details, please see our page dedicated to Finasteride/Propécia.