[Acne] Why don't the same products keep being effective on my skin?

Beauty Tips For Body Care
I've literally tried every cleanser and cream under the sun. Some have been really effective (eg. Neutrogena Cream Cleanser) and improved my skin quickly, but just when I think I could keep using it forever it starts breaking me out! Why doesn't the effectiveness of these products last?
Girls Blog 2015
Submitted by rosetylersouffle