Your skin could be going through a period of ‘purging’, an adjustment period your skin goes through when you’re using a new product when your skin gets worse before it gets better. This is different from a reaction, when your skin is straight-up irritated or allergic to something in the product (which no amount of time can change). Skin care is all about trial and error. The only sure way to find out what is right for your skin is simply to try them out one by one. Whenever introducing new products into your current skincare routine, try only one or two new products at a time and gradually incorporate them into your skin care routine so you'll know the exact effects of the new product, and you help your skin adjust to it. But if irritation continues, you might be allergic to one or more of the ingredients, in which case you should stop using the product!