Beautiful Skin as Easy as A-B-C [part1]

The solution: applying vitamins topically to deliver maximum benefits — everything from improving texture and tone to fading under-eye circles

Vitamin A: Best Overall Age Fighter
Find it in OTC lotions, night creams (vitamin A derivatives are known as retinoids), and prescription products.

Proven to reduce wrinkles, fade brown spots, and smooth roughness. "There are more than 700 published studies on retinoids — they're tried-and-true ingredients. Anyone who wants younger-looking skin should use one," says Doris Day, MD, assistant clinical professor of dermatology at New York University Langone Medical Center.

How to use
Apply your retinoid at night — sunlight inactivates most forms of vitamin A. Prescription retinoids work fastest, within 4 to 8 weeks. The downside: They're irritating, causing redness, scaling, and flaking that last for weeks or longer. OTC products are best for beginners; you'll experience fewer side effects because the retinol they contain is slowly converted to retinoic acid, the active ingredient in Rx creams. To avoid irritation, apply an OTC or prescription retinoid every second or third night, at least for the first 2 weeks, and build up to nightly use. Apply sparingly; a pea-size amount is enough to cover your entire face.

Try
Neutrogena Dermatologics Retinol NX Serum ($65; qvc.com) or RoC Multi-Correxion Night Treatment ($25; drugstores). If your skin is sensitive, two new retinoids are particularly gentle. Clinical studies show that retinyl propionate, available in Olay Professional Pro-X Deep Wrinkle Treatment ($42; drugstores), significantly improves skin after 12 weeks without being as drying as the more potent retinol. Ready to trade up to an Rx retinoid? Ask about Atralin (about $150), which contains two potent emollients. "Even my most sensitive patients are able to tolerate it," says Day.

Vitamin B3: Boosts Hydration to Reduce Redness
Find it in lotions, creams, and serums. It's often called niacinamide on the label.

Proven to increase production of ceramides and fatty acids, two key components of your skin's outer protective barrier. "As that barrier is strengthened, skin is better able to keep moisture in and irritants out — making B3 a great ingredient if your complexion is dry or sensitive," says Leslie S. Baumann, MD, director of the University of Miami Cosmetic Medicine and Research Institute. In one study, a moisturizer with niacinamide improved the flushing and blushing of rosacea, a common condition that can worsen with age. Another B3 benefit: It inhibits the transfer of pigment to skin cells, minimizing dark spots.

How to use
For maximum results, apply B3 in the morning and evening. To reduce irritation from your retinoid, use it in conjunction with niacinamide. "Mix them together in the palm of your hand before applying—they won't inactivate each other," says Baumann. Besides decreasing side effects, the combo produces superior anti-aging benefits.

Try
La Roche-Posay Rosaliac Anti-Redness Moisturizer ($30; CVS) or Olay Regenerist Micro-Sculpting Cream ($25; drugstores).