So I'm going to chuck this out there as no-one else has mentioned it and it totally sorted mine out. I got big shoulder & face flares ups in my late 20s and again after pregnancy in late 30s and has sorted both times, as well as helping if I ever get flare up from too much sunscreen or poor diet every now and again.
Linseeds. Cheap, whole ones (gold or brown, but not ready milled). Stick a tablespoon in a spice mill/grinder attachment of a stick blender. Whizz until the seed cases are broken properly and its a kind of dusty powder - they're hard cases so you need a decent small mill for this, anything that will do coffee beans should work.
I find the most tolerable way to eat it is to mix in with museli or porridge, (add it after cooking so the seed oils aren't ruined by heating them). But you can also add it to salad, or drink with water or apple juice (it gets really slimey if you leave it too long, a bit like fibrogel - don't spin it out!).
There is some science to it...the omega oils in the seeds help balance out skins overproduction of sebum somehow. Once your pores aren't clogged, no more acne.
You need to stick with it for at least 5 weeks to see a difference, so you've done a whole cycle of hormones. Then keep going if you see an improvement.
My diet overall is much better now, so I rarely need to supplement with linseed now, but interestingly, I never found that eliminating anything (dairy, caffeine etc) made a difference.
Having it fresh from seed source is somehow much more effective than an omega oil tablet. It is also very high fibre, so it should help bulk out your 'motions' and help with general gut health too.
Might not work for everybody, but it was like a miracle for me, and like many of you I'd been on the whole medication/pill options without ever properly sorting it out.
I have some scarring still across my upper back, but skin is clear....got to be worth a couple of months of slightly odd breakfasts to give it a shot eh? Nothing cheaper in the market, I guarantee it! About 2 quid for 2 months worth here: www.buywholefoodsonline.co.uk/brown-linseeds-1kg.html?gclid=EAIaIQobChMI7IOE2tPm6gIVied3Ch2OEQnyEAQYAiABEgKjm_D_BwE