What Is Retinization?
Retinization (sometimes called the retinoid purge or retinoid reaction) is the initial adjustment period skin undergoes when retinoid treatment is introduced or dose-escalated. It is characterised by dryness, flaking, peeling, temporary redness, and increased sensitivity that can last from 2 to 12 weeks depending on the retinoid strength, formulation, individual skin sensitivity, and introduction protocol. Retinization is a predictable pharmacological response — not an allergic reaction or sign that retinoids are wrong for the skin.
Why It Happens
Retinoids normalise and accelerate epidermal cell turnover, dramatically increasing the rate at which new cells are produced and old cells shed. The epidermis must adapt its entire structural programme. During this transition, the stratum corneum temporarily thins before thickening with healthier corneocytes; barrier function transiently decreases; and skin sensitivity to environmental insults and products increases. Retinoids also increase photosensitivity, making sun protection even more critical during this period.
How to Minimise the Reaction
Start with the lowest effective concentration (0.025% tretinoin, 0.025–0.05% retinol). Use a buffer method — apply moisturiser first, then retinoid on top — to slow absorption. Begin with 1–2 nights per week, increasing frequency over 6–8 weeks as tolerance builds. Avoid simultaneous use of other actives (AHAs, BHAs, Vitamin C) during the introduction period. Do not skip SPF. Maintain a simple, gentle, hydrating routine.
The purge question: A true "breakout purge" from retinoids can occur — they accelerate the surfacing of pre-existing microcomedones. This should resolve within 4–8 weeks. Breakouts continuing beyond 12 weeks, or appearing in new areas, are more likely a reaction to an ingredient rather than a retinoid purge.
See Retinoids Guide and Tretinoin.