A couple of days ago I had sent an email indicating that there is a belief that nutrasweet products interfere with the efficacy of propecia. The following site describes one such incidence.
Please give me your opinion on this as I have been using propecia for 8 weeks with no effect.
I looked at the reference you cited. The piece proposes that nutrasweet may interfere with the action of Propecia, but it is conjunctural, not factual. Formaldahyde, if it were a significant metabolite of nutrisweet, would/could cause liver disease, which is not a reported side effect.