Skin Whitening Extracts for Cold Process Soap

Regarding your question about adding skin whitening extracts to cold process soap made with coconut oil and sodium hydroxide, it's important to understand the nature of cold process soap.

Cold process soap making involves a chemical reaction (saponification) that creates a high pH environment and generates heat. Many cosmetic active ingredients, including most skin whitening extracts, are sensitive to high pH and heat. Exposure to these conditions can degrade the active compounds, significantly reducing or eliminating their effectiveness.

Based on the properties of common skin whitening extracts, such as:

• WhiteCumin™ (Tetrahydrodiferuloylmethane)
• Phenylethyl Resorcinol (e.q. SymWhite 377)
• Tranexamic Acid (Trans-White™)
• CosmoWhite™ (1-Methylhydantoin-2-Imide)
• Z-White™ (Zinc Glycinate)
• Licorice Extract (Glabridin 4.5%, Water-Soluble)
• SclareoWhite™ (Sclareolide, Pure)
• GlyciWhite™ (Glycinamide HCL)
• MelaninTerminate™ (Hydrolyzed Conchiolin Protein)
• GentiWhite™ (Methyl Gentisate)
• ChromaWhite™ (Dimethylmethoxy Chromanyl Palmitate)
• Hexylresorcinol AF (e.q. Hentowhite)

Most of these ingredients are not recommended for use in cold process soap due to their instability in high pH and heat. While some might be added at trace amounts, their efficacy for skin whitening would likely be minimal compared to their use in other cosmetic product types.

The usage percentages provided in product descriptions (like the 0.1-10% ranges found for these extracts) are typically for leave-on products such as creams, lotions, or serums, where the pH is controlled and there is no saponification process.

For effective skin whitening benefits, these types of extracts are best incorporated into formulations that are compatible with their stability requirements, such as lotions, creams, or serums, rather than cold process soap.