We know this information doesn't exactly answer the question, so we put together a quick guide to the timeframes dermatologists suggest for specific skin-care products.
Your Definitive List of Skin-Care Step Wait Times
Acne Treatments: 1 minute
Prescription topical medications, especially acne medications, definitely require some wait time. They need to be fully melted into your skin before serums and moisturizers are applied on top for maximum efficacy, Shah says.
Dendy Engelman, a board-certified New York dermatologist in New York City, agrees, adding acne treatments need a minute to sit on skin before rubbing creams on top of them to let the active ingredients start doing their jobs.
Retinol: 0 seconds
The better quality a product, the better (and quicker) your skin will sop it up, other dermatologists contest. When using high-quality products, such as retinol, the wait time is even less — possibly nonexistent — because they "are of a different chemistry and will mix and absorb more rapidly" into the skin, says Harold Lancer, a board-certified dermatologist in Beverly Hills.
Serum and Moisturizer: 1 minute
Goldenberg's go-to recommendation for timing between serums and moisturizers is about one minute. This wait has the same reasoning: Sixty seconds — give or take — gives each product a moment to delve into your pores.
Sunscreen: 1 minute
The second exception is sunscreen, which needs some time to itself to be as powerful as possible, according to Sejal Shah, a board-certified dermatologist in New York City. "When sunscreen is mixed with other products, it becomes diluted and less effective," she says.
For this very reason, SPF should be the last layer of your morning skin-care routine. The professionals advise waiting a minute between your moisturizer and sunscreen steps to allow each to penetrate and dry down. (Allure's digital beauty editor likes to get dressed before putting on her face sunscreen.) Then, hold tight for a couple of minutes to ensure that your sunscreen has fully sunken in before moving onto your makeup routine.
Proper layering order is the key to success
All of the experts agree the order in which you're applying products is more crucial than timing. In case you need a quick refresher: "We want to layer starting with the smallest molecule and gradually get larger," Engelman explains. "A good rule of thumb is to start with the lightest product and finish with the thickest, allowing each layer to be fully absorbed by the skin."
