"Purging": worse before better is not a rule
We sell some of what is named here
Routinae sells some of the products written about here, so read this the way you would read any shop’s opinion of its own shelves. Where we think a cheaper product does the same job we say so, and where the evidence is thin we say that too. Our buying standard is published so you can check the argument against it.
Start a retinoid or an acid, break out in week two, and the internet has a ready answer: that is "purging", it proves the product is working, push through. We went looking for the evidence behind that, and it is thinner than the advice.
What the trial data actually shows. In the pooled data we could find on topical retinoids, a minority of people got worse in the first fortnight — and a smaller but real share of the people using only the base cream, with no active ingredient in it at all, also got worse. Skin fluctuates. New products coincide with fluctuations. The story writes itself either way.
So getting worse is not evidence that it is working. It is evidence that your skin is worse, which has several possible causes: coincidence, simple irritation, a formula that does not suit you — and yes, sometimes a genuine adjustment period on ingredients that speed up cell turnover. The problem is that these look identical from the outside, and only one of them rewards persisting.
A workable rule instead: mild, and clearly fading by week three or four — reasonable to continue. Bad and staying bad, or getting worse past that point — stopping is a perfectly legitimate decision, and nobody should make you feel you failed a test. A product that needs six weeks of visible damage before it helps is asking a price most faces should not pay. If what you are seeing is stinging or burning rather than breakouts, that is not purging by anyone's definition — stop, and read this first.
The quiet part: "push through the purge" is advice that always favours the product. Give a new active an honest trial — one change at a time, on calm skin, with sunscreen doing its job — and let week four tell you the truth without a slogan attached.