Difference between Avodart and Proscar is, Avodart is effective on the Scalp, Skin and Prostate and, Proscar is only effective on the Scalp.
Both Avodart (Dutasteride) and Proscar (finasteride) work on only Testosterone and its derivitives like Methyltestosterone and Halotestin which can be converted into DHT. So taking either of the compounds doesn't work with Winstrol, Dianabol, Tren, Primo... which are derivitives either Deca and DHT itself.