Vitamin C is one of the most important anti-oxidants that can help fight skin damage. In the proper formulation, it can lighten or brighten spots and reduce collagen breakdown triggered by sun or environmental stressor as well as from aging. Its formulation is a critical aspect to determine whether it will be effective as it works best in acidic environment.
Applying Vitamin C after hydroxy acid such as lactic acid can potentially enhance Vitamin C's effectiveness. However, take care in combining these two if you have dry skin as the combination can be more irritating. If your skin is oily, however, the combination can be especially beneficial.
One other note on the use of Vitamin C in combination with other important skincare products. Vitamin A analogues such as triretinoin, retinol and adapalene are also beneficial for reversing sun damage, lightening spots and reversing fine lines over time.
However, Vitamin C and Vitamin A products should not be used together as they work best in different pH levels- where Vitamin C products are most effective at a pH below 3.5, while retinol works best at a pH of 5.5-6.0. Vitamin A can also increase sensitivity to sun exposure. For these reasons, vitamin C is best used during the day, whereas Vitamin A is best used at bedtime.
