Feeling like your skincare products aren’t as effective as they were at the start? You may be experiencing tachyphylaxis. It’s a term originally used to describe the tolerance our skin builds up to topical steroids, but it also applies to other skincare ingredients. However, just because your skin is adapting, doesn’t mean that your products are less effective. Rather, your skin has strengthened and is now working more efficiently. Your skin likes consistency, and beauty experts and dermatologists recommend sticking to a product for at least 6 weeks before changing products.