http://www.dutasteride.com/dutasteride-shedding.html
Citazione:When taking Dutasteride the hair follicle is stimulated to start producing new hair. What often happens is that many hair follicles that are in the Telogen phase then go into the growth phase, and first needs to get rid of the old hairs, which are still attached to the hair follicle. Because many follicles react at the same time, a lot of hair will fall out - this is the shedding that you may experience.
Citazione:The initial period of shedding is usually the most intense, however shedding may reoccur periodically throughout treatment. This is also a normal and expected effect of treatment. Because dutasteride triggers a growth cycle, the hair growth cycle becomes more synchronised. As a result, the hairs also enter the Telogen phase almost simultaneously. Over time this shedding will decrease throughout duration of treatment with dutasteride.