When starting a new acne regimen, many acne sufferers note that their new medication makes their acne worse first, before it gets better. Why does it get worse before it improves?
Are you referring to accutane?
FWIW, either both or one of Differin and Duac (both topical) do this as well.
I’m not sure if it gets worse, but back when I used to do customer support for acne products, the basic phenomenon we’d explain is that the pimple you’re seeing today isn’t “brand new”. The pore doesn’t clog and form a pimple instantly. Bacteria buildup or skin cells in your pores cause the acne some time before the problem occurs. The typically line (though I haven’t seen hard data about this) is that this process takes weeks – so if you start a new regimen today, even if it managed to block all future pimples, you’d still be breaking out for some time to come. FWIW, we sold a product that was intended to be an ongoing preventative regimen that was lower dose; we also offered higher dose spot treatments intended to deal with pimples you have right now, but they had a higher likelihood for negative side effects (skin bleaching, dryness, irritation).
I wouldn’t be surprised if seeming ‘worse’ was because the user was paying such close attention due to trying a product, and thus noticing more acne emerge. It could also just be the initial reaction. Dry skin can give some people acne, and it’s a common response to acne treatments, especially at first.