Adding Ingredients to Finished Products

Cosmetic ingredients cannot only be used to create personal care products from scratch but they are also very useful to add to finished products. There are a variety of reasons why you may add ingredients to commercial products:

  • Active Ingredients (Cosmeceuticals): To boost a cream with anti-aging, anti-wrinkle, antioxidant or skin-lightening agents.

  • Colors or mica pigments: To add color or glitter to a body lotion or face cream.

  • Exfoliants: To add additional cleansing power to your a cleanser.

  • Fragrances: To add or change the scent of a product.

Factors to Consider

There are, however, a few things to think about when mixing additional ingredients into finished products. It is important to know that not all ingredients are suitable to add to finished products and even those ingredients that are suitable cannot be added in unlimited amounts.

  • Solubility: Oil-soluble ingredients (e.g. oils) cannot be added to water-based products (e.g. toners), and water-soluble ingredients (e.g. proteins) cannot be added to oil-based products (e.g. bath oils). However, both oil-soluble and water-soluble ingredients can be added to emulsions (e.g. creams and lotions). Certain powders like titanium dioxide and zinc oxide do neither dissolve in oil-based products nor in water-based products.

  • Stability: As a rule of thumb, additional ingredients should not be added to finished products at a concentration of more than 10-15%. Otherwise, a finished product, particularly emulsions, can become unstable and even separate into its oil and water phase. Also, a finished product may get liquefied and diluted too much and lose its consistency. If you still want to add more than 10-15% of additional ingredients to a cream consider using an especially thick cream which is formulated specifically to allow the addition of up to 20-25% of additional ingredients without the risk that the emulsion breaks apart.

  • pH Value: Adding acids or alkaline ingredients to finished products can push the pH value to extreme levels where emulsions can break apart or a product can even become skin irritant.

  • Contamination: Adding ingredients to finished products can increase the risk of bacterial or fungal contamination since the preservatives of the product will be diluted and/or bacteria may be introduced into the product if the added ingredients are not preserved. When adding either unpreserved ingredients or more than 10% of ingredients to a finished product we recommend to add additionally a preservative.