Formulation Advice for Melasma, Uneven Tone, and Wrinkles

Regarding the proposed formulation for your 45-year-old sister with melasma, uneven skin tone, some wrinkles, and normal to dry skin:

Your selection of ingredients targets the concerns well. Double Hyaluron Liquid provides hydration, Matrixyl helps with wrinkles by stimulating collagen, and Nano White and Delentigo are aimed at brightening and reducing dark spots.

Based on the staff's recommendation, adding Vitamin B3 (Niacinamide) and N-Acetyl Glucosamine (GlucoBright™) is an excellent suggestion. These two ingredients work synergistically to effectively brighten skin and reduce dark spots and uneven tone, complementing the effects of Nano White and Delentigo.

For hydration, you included Vitamin B5 (Panthenol), Beta Glucan, and Homeostatine. As the staff mentioned, using all three might be more hydration than needed for normal to dry skin. Beta Glucan is beneficial not only for moisture and soothing but also has an indirect brightening effect, making it a good choice to keep in the formula, especially varieties like Beta Glucan from oat extract.

Regarding the use of a Vitamin C Kit (such as Vitamin C E Ferulic) alongside this cream: It is possible to use both, and it could potentially enhance the results for brightening and anti-aging. However, as the staff advised, it is generally recommended to use them at different times of the day. For example, you could use the Vitamin C Kit in the morning and the custom-made cream in the evening. Using them separately also helps you observe which product is providing the most benefit to the skin. Vitamin C E Ferulic is acidic, so applying other products immediately after might affect their efficacy or cause irritation.

Important Note: As highlighted by cosmeceutical7, consistent use of sunscreen is absolutely crucial. Sun exposure is a primary cause of melasma and uneven skin tone. Protecting the skin from UV damage is essential to prevent existing issues from worsening and to maintain the results from your skincare efforts.

In summary, your proposed formulation is a good starting point. Incorporating Vitamin B3 and N-Acetyl Glucosamine is highly recommended for addressing pigmentation. Consider adjusting the moisturizing components based on your sister's skin's needs. You can use a Vitamin C Kit as well, but apply it at a different time than the custom cream, and always, always use sunscreen daily.