12 Common Beauty Questions, Answered
Finally, solutions to your cosmetic conundrums.
1. Some creams come with a thin plastic lid under the cover. Should I keep it or toss it?
Keep it, says Mary P. Lupo, a dermatologist in New Orleans. Exposure to light and air breaks down many active ingredients, including vitamin C and retinol, making them inert. Also, store these products in a cool, dark place to help maintain their efficacy.