If crow's feet are beginning to crisscross your face, but you haven't unleashed retinol on them, new scientific evidence might prod you to consider doing so.

Potent prescription forms of retinoic acid (tretinoin), such as Retin-A, remain the gold standard for anti-aging benefits, reducing the appearance of fine lines, wrinkles, discoloration and other sundry signs of sun damage, dermatologists say.

But over-the-counter vitamin A formulations, particularly retinol, are gaining skin cred. Two studies published in scientific journals in the past year suggest that topical retinol packs more line-fighting power than originally believed, at lower doses than were previously studied. Bonus: Retinol typically causes less irritation and redness — and costs less — than prescription retinoic acid.

One clinical study reported last year in the journal Skin Pharmacology and Physiology concluded that 0.1 percent of retinol improved fine-line appearance and skin tone after 12 weeks and did not trigger significant irritation. Improvements continued throughout the 36-week study.

Previous studies focused on retinol formulations of 0.4 percent and more, doses that can cause skin irritation.

"Now we know that over-the-counter retinol can have clinically beneficial effects without significant side effects," said Dr. Alan Logan, a licensed naturopathic physician who has written skin-care books with medical doctors.

Not all brands disclose the percentage of retinol. Logan suggests comparing labels to see where retinol falls on the ingredients list. (Higher equals more.)

If you're new to retinol, start with a lower concentration and less frequent use, said dermatologist Howard Sobel, founder of the DDF (Doctor's Dermatologic Formula) skin care line. Sobel notes that retinols are not recommended for use during pregnancy and reminds users to wear sunscreen. Read all the directions on retinol packaging.

• RoC Retinol Correxion Deep Wrinkle Night Cream has a good reputation among dermatologists. $21.99 for 1 ounce; drugstore.com

• Perlabella PureDose Pearls are gel capsules designed to protect the retinol serum from light and air. Once applied, the retinol is gradually released to minimize irritation. The face product has .075 percent retinol; the eye product has .03 percent. $19.99 for 28 capsules; walgreens.com

• DDF Retinol Energizing Moisturizer combines retinol with protein extracts and antioxidants. $88 for 1.7 ounces; drugstore.com

• Intensive Deep Wrinkle Treatment with MMPi-20 and Retinol by New York dermatologist Patricia Wexler is designed to stimulate cell turnover, minimize the appearance of wrinkles and pores, and moisturize. $60 for 1 ounce; bathandbodyworks.com; 800-756-5005

• Philosophy On a Clear Day Retinol Clarifying Lotion blends 0.075 percent retinol, hyaluronic acid and cucumber extract to improve the skin's texture and clarity and minimize the appearance of pores and discoloration. The retinol is gradually released to minimize irritation. $40 for 0.75 ounce; philosophy.com