Mixing Raw Materials into Finished Skincare Products: Compatibility and Stability

Question

I want to mix raw materials into finished skincare products. First, can I mix ActiveRelease Retinal™ into Paula's Choice 2% BHA Liquid Exfoliant (liquid, clear) with the following ingredients: Aqua, Methylpropanediol, Butylene Glycol, Salicylic Acid (Beta Hydroxy Acid, Exfoliant), Polysorbate 20 (stabilizer), Camellia Oleifera (Green Tea) Leaf Extract (skin calming/Antioxidant), Sodium Hydroxide (pH balancer), Tetrasodium EDTA (stabilizer)? Second, I want to mix the following raw materials into Estee Lauder Micro Essence Skin Activating Treatment Lotion (liquid, clear) with the following ingredients: Water, Bifida Ferment Lysate, Peg-75, Propanediol, Butylene Glycol, Betaine, pentylene glycol, Lactobacillus Ferment, Acetyl Hexapeptide-8, Acetyl glucosamine, Trehalose, Caffeine, Sodium Hyaluronate, Anthemis Nobilis (Chamomile), Caprylyl Glycol, Carbomer, Ppg-5-Ceteth-20, Citric Acid, Potassium Sorbate, Sodium Citrate, Tromethamine, Disodium EDTA, Phenoxyethanol. The raw materials I want to add are: Repair Activator, Perfect-C™, Ectoin, Matrixyl 3000, Satin Cream Maker™ (emulsifier), Nano Colloidal Gold (penetration enhancer). My proposed mixing procedure is: A) Mix Perfect-C™ + Nano Colloidal Gold. B) Mix Repair Activator + Ectoin + Matrixyl 3000 + Satin Cream Maker™. C) Mix A + B. D) Add C to the micro essence lotion and mix again. Are these ingredients compatible? Is this mixing procedure correct? Are there any prohibitions, exceptions, or additional recommendations? Since I am experimenting with small quantities, can I use a milk frother instead of a blender?

MySkinRecipes Expert · Accepted Answer

Mixing active ingredients into finished skincare products is generally not recommended because it can compromise the stability, efficacy, and safety of the original formulation. Pre-formulated products are carefully balanced systems. Adding ingredients can disrupt the pH, preservation system, and ingredient compatibility, leading to unpredictable results.

Regarding your specific questions:

Mixing ActiveRelease Retinal™ into Paula's Choice 2% BHA Liquid Exfoliant:
- ActiveRelease Retinal™ (Retinaldehyde) is a retinoid, which typically works best at a neutral to slightly acidic pH.
- Paula's Choice 2% BHA Liquid contains Salicylic Acid, an exfoliant that requires a low pH (acidic) to be effective.
- Mixing ingredients with significantly different optimal pH ranges can reduce the efficacy of one or both ingredients and may increase the risk of skin irritation.
- Adding ActiveRelease Retinal™ to a finished BHA product is not recommended due to potential compatibility issues, pH conflicts, and the risk of destabilizing the formulation.
- Using a blender would help with initial dispersion but would not resolve the underlying chemical compatibility and stability problems.
Mixing multiple ingredients into Estee Lauder Micro Essence Skin Activating Treatment Lotion:
- You are attempting to add several active ingredients, including an oil-soluble one (Perfect-C™) and an emulsifier (Satin Cream Maker™), to a water-based essence.
- Adding an oil phase and an emulsifier to a finished water-based product is highly likely to cause instability, separation, and changes in texture because the original essence is not formulated to incorporate these components.
- Adding multiple active ingredients without proper formulation knowledge can lead to unpredictable interactions, reduced efficacy, or increased irritation.
- The proposed mixing steps attempt to create a mini-emulsion, but adding this to the essence is still problematic for stability.
- A milk frother may not provide sufficient mixing or shear force to properly emulsify the ingredients, potentially resulting in an unstable or separated mixture.
- This mixing approach is not recommended due to the high risk of instability, reduced efficacy, and potential negative effects on the skin.

Recommendations:

For best results and safety, it is strongly recommended to use raw materials to create your own formulation from scratch if you wish to combine multiple active ingredients. This allows for proper control over ingredient compatibility, pH, stability, and preservation.
Alternatively, consider using the finished products and the individual active ingredients separately in your skincare routine, applying them at different times if necessary, based on their compatibility and recommended usage.

We advise against modifying finished cosmetic products by adding raw materials due to the risks involved.