Tretinoin (All-Trans Retinoic Acid)
Urea (5%–10%)
How to Layer These Actives in Your Routine
Tretinoin (All-Trans Retinoic Acid)
Apply first to clean, dry skin. Operates at pH 5–6.5.
Allows cutaneous acid mantle to equilibrate before the next step.
Urea (5%–10%)
Layer over the initial active. Operates at pH 5.5–6.8.
Biochemical Mechanism & Pharmacology
Urea (5%–10%) provides vital physiological lipids and humectants that reinforce the stratum corneum lipid matrix, preventing trans-epidermal water loss (TEWL) and buffering against irritation from Tretinoin (All-Trans Retinoic Acid) without attenuating its therapeutic cellular benefits.
Apply the lower viscosity product first, or buffer by applying Urea (5%–10%) prior to Tretinoin (All-Trans Retinoic Acid) for sensitive skin (the sandwich method).
Recommended 7-Day Routine Blueprint
| Morning (AM) Routine | Evening (Night A) | Evening (Night B) |
|---|---|---|
✓Gentle Cleanser ✓Urea (5%–10%) ✓Broad-Spectrum SPF 50+ | •Tretinoin (All-Trans Retinoic Acid) •Urea (5%–10%) •Barrier Seal | •Tretinoin (All-Trans Retinoic Acid) •Urea (5%–10%) •Barrier Seal |
Obstetric & Pregnancy Safety Summary
View Full Pregnancy Directory →Tretinoin (All-Trans Retinoic Acid) is classified as DEFER IN PREGNANCY during pregnancy, while Urea (5%–10%) is classified as PERMITTED under clinical guidelines. Always cross-reference with your physician if expecting.