Tretinoin

Tretinoin is the gold-standard retinoid active, but without a full formula, efficacy hinges on concentration, pH, and stabilizers—pure ingredient scores high potential yet demands prescription-grade formulation. Efficacy score of 4.8 calculated for the active itself due to its direct retinoic acid structure (no weak derivatives like retinyl palmitate), superior to OTC retinols in potency and receptor binding, but real-world products deduct for instability without encapsulation or antioxidants like BHT; optimal at 0.025-0.1% in pH 4.5-6.0 anhydrous bases to prevent degradation[1][5].