I had an acne issue when I was in my 30's. The zits would be a collection of 3-5 small zits in one big bump!!!
A local herbalist gave me two tinctures to take - dandelion and burdock. (5 drops per day of each for the first week, then 3 drops a day of each for 3 months).
He told me that it would be a slow process. As I remember, he said it was candida that had gotten its tentacles into the bones of my face and it would take a while to get them 'weeded' out.
I didn't change my diet at all, I just took the drops in a glass of water the first thing in the morning. Sure enough, after 3 months I never had one of those big zits again. And that was almost 20 years ago.