Many know it as the injectable, polynucleotide treatment, colloquially known as the “salmon sperm facial”, but a slew of topical products featuring the ingredient is the latest export from South Korea. While it may sound new, it’s been used since the 1990’s as a pharmaceutical treatment for tissue repair, including treating burns and repairing tendons. The next best option are PDRN serums and creams—however, as Consultant Dermatologist Dr Zainab Laftah explains, not all are created equal. Who is topical PDRN good for? If you have dry, dehydrated, sensitive or compromised skin, PDRN is a great option.