Demonstrating The Efficacy of Low Levels of Retinol Versus Other Vitamin A Derivatives and Other Retinol Alternatives

Retinoic acid is the gold standard in dermatology for reversing signs of skin aging. However, retinoic acid has the potential for instability and irritation. To overcome this, derivatives of vitamin A and alternatives have been developed. It is believed that the molecule with the least conversion steps to retinoic acid will provide more significant anti-aging benefits. Skin explant and in vivo studies were conducted to show that overall product efficacy depends on molecular stability, delivery mechanisms, and formulation synergy, highlighting the importance of evaluating the complete product matrix. When formulated appropriately, retinol can be used at very low levels to deliver high efficacy and tolerance.

Methods:

• Protein level analysis of retinol versus alternatives in skin explants
• Patch test of retinol formulations versus control
• Clinical studies of retinol formulation for efficacy and tolerance

Results:

1. In the explant study, 0.07% retinol was the only ingredient that had a positive effect on the CRABP2 at Day 2, with an increase of 30%. On Day 5, retinol was equivalent to 0.2% hydroxypinacolone retinoate and superior to the other tested ingredients. When tested for Filaggrin expression, Retinol was superior to 0.2% hydroxypinacolone retinoate, 0.2% retinyl palmitate, and 0.25% bakuchiol ester.
2. When tested under occlusion and compared to untreated control, formulations containing 0.110% and 0.055% retinol showed erythema was not elevated and visual dryness was better.
3. When tested in vivo, in two separate clinical studies, a retinol formulation containing 0.015% retinol was shown to be efficacious for wrinkle reduction and very well tolerated.