Dr. Neal Schultz: Hello I'm Dr. Neal Schultz and welcome to DermTV.A viewer recently asked if she needs to change her products periodically because she was told that her face becomes accustomed to the skincare product and the active ingredients and therefore after a while they stop working that is not true. But places like New York, where DermTv.com is, where we have distinct seasons there is reason to change your skincare products according to the season.Lets take a look at these two different glycolic products, first is an 8% glycolic cream and second is an 8% thin glycolic lotion.In New York in the summertime it's warm and humid and we want to use very light weight products like the 8% lotion because we do not want anything heavy on our skin when the temperature is warm and humid. We want the 8% glycolic but in a thinner more pleasing vehicle. In the wintertime when it's dry and cold we want to use a cream. It is the same 8% glycolic, we're not changing the active ingredient, but we want to use it in a vehicle which is better suited for dryer and cooler weather.So, there is no reason to change your active ingredients if they are working, but there is a reason to change the formula that they are in periodically. In New York usually it's around May we want to change to thinner, lighter products and around the end of October or the beginning of November when we want to change to heavier products.Please join me again at dermtv.com. If you have a question please send me by visiting dermtv.com/question. I'm Dr. Neal Schultz and thank you for watching today.