Hi there... You most probably is having androgenetic alopecia(AGA) for which the has adviced you to start with finastride...Yes it is an approved and time tested drug for AGA...For AGA the recommended dose is 1mg/day so you should take the same. 5mg/day is the dose for benign prostate hyperplasia which is entirely a different disease so dont follow it... Talking about the 5mg every 5th day as you say: first this is not recommended as a it will not maintain the constant deried level of drug in the blood... There are a list of side effects associated like- Decreased sexual ability/desire, lump in the breast, nipple discharge, breast enlargement/tenderness/pain, pain in the testiclesetc..though they are less with the prescribed dose for AGA Remember to take it under your doc advice only... As your doc can better judge and prescribe the same only if the benefit to you is greater than the risk of side effects... Hope you find this helpful..