My husband had two rounds when he was younger, and all three of my kids had horrid acne too.
My oldest (now 24) had the best luck, he had one treatment round and very good results. Worst side effect for him was dry membranes - couldn't wear his contacts at all.
My middlest (now 22) did two rounds, still has breakouts. Also did rounds of prescribed ointments and antibiotics.
My youngest (now 20) also did two rounds, and now on antibiotics, skin quite clear now.
All under very careful and close care - monthly blood tests, strenuous warnings and pregnancy preventives!!