injection spot

im taking Canada Labs Masteron Prop at the moment bc i jus finished my other bottle of British Dragon Masteron Prop....the BD masteron was alot darker in color and hurt wen injected in shoulders n legs...worked well....the Canada Labs one is alot clearer and doesnt hurt after injection even in...

hey my question is does it matter where i inject it i know to switch body parts every time but if i keep it just on my cheecks and thighs (what im doing right now)would that be ok? or do i NEED to switch to my shoulders and upper body to see an increased result? (my friend doesnt feel confident...