I was baffled when I recently met with Zein Obagi, MD, a Beverly Hills-based dermatologist and founder of skin-care line ZO Skin Health, who told me using moisturizer was not only a waste of time, but potentially damaging to my skin. “When you use moisturizer every day, you run the risk of making your skin older, not younger,” he warned. “If you apply a lot of moisture, skin will become sensitive, dry, dull, and interfere with natural hydration.”

What, you ask, is the scientific explanation behind this? Dr. Obagi believes skin gets addicted to replacement moisture and stops supplying its own hydration from within the body. And your natural hydration, he says, is what really keeps skin healthy and young. “The tree gets its nutrients from the ground; no matter how much you spray the tree, it will become dry,” he says.

It makes sense when I remember the reverse wisdom that was commonly cited in my teen years: When you overdry your skin with too many zit zappers, your skin responds by producing more oil to compensate. “Almost zero percent of my patients actually requires a moisturizer,” he explains. “All your skin really needs is cleansing, stimulation, and protection.” Even season changes don’t count. Daily moisturizer should not be needed no matter the calendar, he says.