Acne, infections and the skin side of a cycle
Isotretinoin for acne that does not answer to anything else, aciclovir for cold sores, and a short row of antibiotics: azithromycin, amoxicillin, co-amoxiclav and doxycycline.
Androgens raise sebum production, so acne on the back and shoulders is one of the commoner complaints on a heavy cycle. Isotretinoin is a course measured in months with real side effects and bloodwork to match, not something to start on a whim.