The depth of color is created by the amount of DHA applied and the amount of protein present in the skin. In areas where the stratum corneum is thicker, such as the palms, soles, elbows, and knees, the brown color appears darker.
Q. How can the color of self-tanning creams be adjusted?
A. I recommend self-tanning creams for my patients who want some color, but they tell me the end result is too dark or too orange.
Self-tanning creams are being recommended by dermatologists more frequently as patients are told to use them to achieve browner skin without sun exposure. All self-tanning creams contain a 3-carbon sugar that appears as a white, crystalline hygroscopic powder known as dihydroxyacetone (DHA). DHA is formed when glycerol is fermented by Gluconobacter oxydans. It interacts with amino acids, peptides and proteins to form chromphobes known as melanoidins. Melanoidins structurally have some similarities to skin melanin, but are not photoprotective.
The depth of color is created by the amount of DHA applied and the amount of protein present in the skin. In areas where the stratum corneum is thicker, such as the palms, soles, elbows, and knees, the brown color appears darker. In areas where the stratum corneum is thinner, such as the face, the resultant brown color is lighter. This is why skin exfoliation prior to applying the self tanner can cause a lighter brown stain.
The pH level of the skin and the formulation can also change the color of the DHA-induced skin stain. If the skin or the formulation is alkaline, the DHA color will be more orange. Conversely, if the skin or the formulation is acidic, the DHA color will be more natural in appearance. The optimal pH for the best color development is 5-6. For this reason, the self-tanner should be applied to freshly washed skin to avoid uncontrollable color development.
The amount of water in the formulation can also affect the DHA color. If too much water is present, the DHA color will be lighter. This may be desirable for those who think the color is too dark. The color can be lightened by applying the product to moist skin or mixing a small amount of water with the product in the palm of the hand prior to application.
Conversely, there are those who want a darker self-tanning color. It has been noted that propylene glycol and sorbitol increase the tanning intensity. These are some easy to relate suggestions that can be shared with patients.