Anti-aging is the largest segment of professional skincare services, and also the most competitive. Clients seeking visible improvement in fine lines, loss of firmness, hyperpigmentation, and skin texture have more options than ever — from at-home devices to medical-grade treatments. For estheticians to remain the treatment of choice for this client segment, professional anti-aging facials must deliver measurable, visible results that justify the investment and differentiate professional care from what clients can achieve independently. The Biology of Skin Aging Understanding the mechanisms of skin aging informs protocol design. Intrinsic aging — the genetically programmed deterioration of skin structure — involves...