Question: I purchased the Glycolic Kit. However, I also have retina A at home.   Can I use both products or do they contradict each other? Answer: Glycolics actually work well in conjunction with other types of products such as Retin-A, Retinol, Vitamin C, and bleaching agents. With prescription-strength products, it is recommended that you alternate usage of the glycolic and the prescription product to avoid possible irritation.