Activated charcoal has a highly porous surface that binds to oil, dirt, and residue as you wash, which is the real mechanism behind why it can help with everyday shine and clogged pores — it is not just a trend claim. That said, charcoal soap is not a treatment for diagnosed acne, and it can tip into over-drying skin if used more than once daily, which often backfires by triggering more oil production to compensate. If you have persistent or painful breakouts, that is worth discussing with a pharmacist or GP rather than relying on soap alone. For everyday oiliness and blackhead-prone skin, a charcoal bar used once a day, followed by a proper moisturiser, is a reasonable and inexpensive addition to a routine — just patch-test first, as with any new product.