You come home from the store excited about a new product’s ability to smooth your wrinkles, lighten your brown spots and clear up your acne. But a few days in, the lack of results leaves you frustrated. So you toss it and try another. “Switching products and changing up your skin care routine too quickly can create issues like redness, irritation and breakouts, and make it difficult to find the root cause of your skin problems,” explains Mitchell Chasin, M.D., a dermatologist and medical director of Reflections Centers for Skin & Body in New Jersey. You’ve got to give a new product a chance. “A good moisturizer will yield results immediately, but other products, such as those containing lightening agents or an acne-fighting topical product might take a month or more for appreciable results to be seen.” Wait four to six weeks to gauge results -- it takes that long for skin cells to turn over.