Karen Spear needed a passport to discover the sunscreens she wanted.

Ms. Spear, a school psychologist in New York who has suffered from past overexposure to the sun, said she was looking for extra protection for her skin. She finally got what she needed on trips to the Caribbean and Europe.

"I noticed that the consistency was better and nicer and not as expensive and gooey as the ones you buy in the States," she said. "It is definitely much better than any of the sunscreens bought from the drugstores or cosmetic companies."

After doing some research and consulting with her dermatologist, Ms. Spear learned of the key ingredient, Tinosorb S. About a year ago her son ordered online a European sunscreen, Avène Emulsion SPF 50+, not available in the United States. At $18, she found the price reasonable.

She is part of a group of attentive U.S. consumers savvy enough to find certain kinds of sunscreen despite regulations that make a purchase tougher than a trip to the corner pharmacy.