As estrogen levels decrease, testosterone takes over, which can trigger acne flare-ups. Collagen production also diminishes, causing skin to become thinner and more vulnerable to bacteria. Restore balance and firmness with a moisturizer that contains soy, a phytoestrogen. Treat current blemishes with an exfoliating 2 percent salicylic-acid gel, which is milder than both benzoyl peroxide and sulfur.
Aveeno Clear Complexion daily moisturizer, $17; drugstore.com
Bliss No Zit Sherlock spot treatment, $18; blissworld.com