Is there a way to determine if the bottle benzoyl peroxide I have is no longer effective? I heard this can happen. I've had a 32 is bottle for about 2 months now but have been on the regimen for almost 2 years. While I have not had full resolution of my acne it has cleared up a lot. I currently have breakouts on my forehead and cheeks and it's spreading and getting worse with no signs of clearing up. Does anyone have any advice?
I don't believe it loses its efficacy. It is very effective at killing p.acnes that invade pores to cause acne formation. However, it is possible that the drying nature of the BP is causing in up-regulation in sebum/oil production due to its drying nature therefore leading to worsening symptoms. It causes dryness because of the oxidizing reaction and skin shedding which may clog pores. It should be used as a spot treatment for best results in my view.