Retinaldehyde Serum Color Change

Question

My Retinaldehyde serum formulation (0.05% Retinaldehyde, 3% UltraSolve, 1% ActiveProtec UV in water with Vitamin B, Glycol, Alcohol), mixed according to a previous recommendation but with reduced Retinaldehyde concentration (0.05% instead of 0.1%), changed color quickly from pale yellow to dark brown within just a few days. I understand Retinaldehyde is sensitive to light and inherently unstable in various product forms. Based on the previous advice, why did this rapid color change occur, and was something essential missing from the recommended method to prevent this discoloration?

MySkinRecipes Expert · Accepted Answer

Retinaldehyde Formulation Color Change

The rapid change in color of your Retinaldehyde formulation from yellow to dark brown is a common issue and is primarily due to the oxidation of Retinaldehyde. Retinaldehyde is highly sensitive to both light and air (oxidation), leading to its degradation.

While you included ActiveProtec™ UV, which provides UV protection and some antioxidant benefits, the product information for Retinaldehyde and ActiveProtec™ UV specifically highlights the importance of ActiveProtec™ OX for oxidation protection in Retinaldehyde formulations. The Retinaldehyde description recommends that ActiveProtec™ OX at 1% should always be used in such formulas to help protect the Vitamin A from deterioration.

Therefore, the likely reason for the quick color change is insufficient oxidation protection. Adding ActiveProtec™ OX at a concentration of 1% to your formulation is crucial for stabilizing the Retinaldehyde and preventing this rapid discoloration caused by oxidation.

Other factors that contribute to Retinaldehyde stability include:

Storing the final product in an opaque, airtight container to minimize light and air exposure.
Avoiding heat during the manufacturing process.
Ensuring the formula pH is within the recommended range of 3.5-6.5.
Using Vitamin B3 (Niacinamide) alongside Retinaldehyde, which you are already doing.

Incorporating ActiveProtec™ OX is the key step needed to address the oxidation issue you are experiencing.