Hi there! I just wondered how long I should give products to see if they are right for me or not? is it for a month or more?

I was using Cerave moisturising cream but now changed to Avene Tolerance Extreme Emulsion and a serum called Vichy mineral 89 serum. Been using these for a couple of days now.

Just have a breakout around my chin. Possibly could be down to little sleep and stress.

Any help is appreciated.