Smoking apparently reduces estrogen levels, and so quitting smoking may alter the hormonal profile and perhaps cause acne.
Correct me if I'm wrong but aren't androgens the cause of acne? This considered smoking would increase the likelihood of acne and quitting reduce it?
About 6 months ago I started smoking cigarattes again after a year or so of quitting. After a couple of months I started getting oily skin and mild acne. I gave up smoking analogs cold turkey again when I started vaping about a month ago and the oily skin has suddenly gone, I'm a little dry now if anything. I don't want to jinx myself but I thought this was interesting and likely related, perhaps not. I have been vaping very lightly on low/medium nice juice and, for the past couple of weeks vaping hardly at all on zero nic juice.