Difficulties Adding Whitening Agents to Alkaline Glycerin Soap Base

Subject: Re: Making a bar soap for skin whitening

Thank you for your question regarding adding ingredients for skin whitening to your glycerin soap base.

Based on our previous discussion, standard glycerin soap bases are alkaline (have a high pH). This presents a significant challenge for adding most safe and effective whitening agents.

Many common whitening ingredients are unstable in alkaline conditions. When added to a high-pH soap base, they can:

• Degrade and lose their effectiveness.
• Break down into other substances, some of which could potentially be harmful (as mentioned previously, Alpha Arbutin can break down into Hydroquinone in alkaline conditions).

Therefore, it is very difficult to achieve significant and safe skin whitening by simply adding typical whitening ingredients to a standard alkaline glycerin soap base.

If your primary goal is significant skin whitening, you might need to consider alternative approaches, such as using leave-on whitening products (like serums or creams) which are formulated at a stable pH, or finding a specialized low-pH (pH 5.5) soap base, although these are much more expensive and less common than standard glycerin bases.

Adding standard whitening agents to your current alkaline glycerin base is generally not recommended due to issues with stability, efficacy, and potential safety concerns.