You were so careful all summer with the sunscreen. You applied it head to toe before you left the house to go to the beach, or pool, or club, or to lie out in the sun. And you even reapplied your sun protection every two hours. You have a hat, a surf shirt with UV protective fabric—you were committed!

But...you still got a tan. OK, it was cloudy one day and you didn't realize so much sun (50 percent) gets through. Plus, you forgot your tube of sunscreen at home and you stayed out a little longer. And the last weekend of summer, you were just too relaxed to stress over anything.

And now you're tan. And feeling maybe a little regret or guilt or even concerned. It's time to go back to work looking rested and healthy and that too tanned look actually looks haggard. What can you do? How do you take away the tan and get back to healthy skin?

Here are a few tricks.

First: Unexciting but simple—resume your sunscreen use. Drop the number from SPF 30 to SPF 15. Use the sunscreen stick or foam applicator when you reapply mid-day. Remember, the celebs wear sunscreen indoors too! (Especially inside airplanes.)

Second: Start using a bleaching cream at night on your brown patches. Hydroquinone 4 percent is the key ingredient found in combination with glycolic acid, tretinoic acid, or hydrocortisone creams. Don't go higher than 4 percent because too much can lead to blue-black permanent skin discoloration (called ochronosis.)

Third: Use a creamy exfoliater daily. This removes the tough, tobacco colored dead skin faster and helps to restore your glow.

Fourth: Invest in a medium strength chemical peel or even smarter—a Fraxel laser resurfacing treatment. This will help remove damaged cells as well as brown pigment. Remember, tan is trauma. It reflects cells that have been heated up and are in emergency defense mode. Melanin pigment makes us tan (which for some reason makes us feel young and beautiful again) but its sole purpose is to defend DNA from further UV attack. It literally covers the DNA like a shield. But if you're tan, your DNA has already been hit and possibly mutated and this is where skin cancer starts. Resurfacing and peels remove the surface cells and may help eliminate early skin cancer cells.

Fifth: Eat well. Food is the best way to optimize your immune system to heal thyself. Eat salmon and sunflower seeds and avocado and drink green tea. For a comprehensive guide to what to eat for good skin check out chapter three in "Simple Skin Beauty."

Tanning was just recently upgraded from a possible to a known carcinogen by the World Health Organization. You've heard the sunscreen message a million times before but let it sink into your skin. Enjoy your active lifestyle but use protection-it will be one of the best investments you'll ever make.

Dr. Ellen Marmur is an Associate Professor and the Chief of Dermatologic and Cosmetic Surgery at The Mount Sinai Medical Center in New York City. Dr. Marmur specializes in skin cancer, surgery, cosmetic surgery, and women's health dermatology. She is the author of "Simple Skin Beauty" (Atria Publishing).  Check out her website ellenmarmur.com.