For decades, traditional cosmetology has taught us to follow a simple classification: skin can be dry, oily, combination or normal. According to this type, we are used to buying jars of creams, lotions and foams. However, modern 4P medicine (personalized, predictive, preventive, patient-centered) proves that this approach is too superficial. Our skin is not just a physical shell, it is the largest organ of our body and a complex ecosystem inhabited by billions of microorganis