What is hydroquinone?

A powerful chemical lightening agent, hydroquinone is available over the counter in 0.5 to 2 percent concentrations and by prescription in 4 percent or higher. Contrary to popular belief, hydroquinone won’t bleach your skin. Rather, it suppresses the production of melanin, (the chemical that gives skin its color) by inhibiting an enzyme called tyrosinase. Unprotected sun exposure, hormonal changes, medications, skin conditions like eczema and acne can all increase melanin production, leading to dark spots and uneven skin tone known as hyperpigmentation.

Safety concerns about hydroquinone

There’s ongoing debate over hydroquinone’s safety. When used as directed, dermatologists consider it to be safe and highly effective. In fact, it's viewed as the gold standard for treating hyperpigmentation. However, hydroquinone can irritate the skin, particularly when using higher prescription-strength formulas.

Despite dermatologists' stance that hydroquinone is safe, the Food and Drug Administration (FDA) is considering a ban on over-the-counter products because of the following concerns:

• Cancer: Some animal studies, where rats ingested high doses of hydroquinone, have suggested that the ingredient may be carcinogenic. However, Jacob Levitt, M.D., dermatology professor at Mount Sinai Medical Center, stresses in Cosmetic Surgery Times that the rats who suffered tumors “even without hydroquinone exposure…were genetically predisposed to do so, so it was unfair to link their tumors to hydroquinone.”

  This research may not apply to humans, anyway. In the studies, rats were given high doses of hydroquinone internally, whereas humans use lower doses of hydroquinone topically. Paul M. Friedman, M.D., dermatology professor at the University of Texas at Houston, tells WebMD that “hydroquinone has been used over the last 40 years, and there has not been a single documented case of either skin cancer or internal cancer associated with it.”

• Ochronosis: Hydroquinone can cause a more permanent form of hyperpigmentation known as ochronosis, where the skin tissue turns blue or black. Dermatologist Leslie Baumann, M.D., notes on Yahoo! Health that only 30 cases of ochronosis have been reported in North America, even though hydroquinone is widely used. G. Todorov, Ph.D., of Smart Skin Care, writes that ochronosis is more likely to occur in dark-skinned patients who use high concentrations of hydroquinone over extended periods of time.

  The American Academy of Dermatology (AAD) disagrees with the FDA's proposal to ban hydroquinone.

Long-term treatment

Before starting any skin-lightening regimen, it’s important to understand that the primary cause of hyperpigmentation is unprotected sun exposure. So if you're serious about fading dark spots or an uneven skin tone, be prepared for a long-term commitment. The process requires diligence: Results can take from one to three months. Remember, in addition to trying to diminish existing damage, you're protecting your skin against new damage, too. Here are some tips:

• Apply lightening products once or twice daily.

• Be sure to follow instructions carefully.

• Wear sun protection every day in order to maintain results and prevent new damage from forming. This includes wearing sunscreen with SPF 30 when driving, flying and even sitting next to a sunny window. Any unprotected sun exposure can cause additional hyperpigmentation and undo the positive results from treatment products.

Skin-lightening options

If you're interested in products without hydroquinone, check out these ingredients:

• Arbutin: Derived from the leaves of blueberry, bearberry, cranberry or mulberry shrubs, or from certain genus of pear, arbutin contains the natural form of hydroquinone. It inhibits skin’s melanin production. In addition, according to Dr. Todorov, arbutin seems to be gentler than hydroquinone when it comes to skin irritation.

• Azelaic acid: Most commonly, this ingredient treats acne, but recent studies have shown it benefits skin discoloration, too. Azelaic acid is made from wheat, rye or barley, and is usually found in creams at a concentration of 20 percent. Studies have shown it’s effective in treating melasma and inhibiting melanin production. According to dermatology professors R.M. Halder, M.D., and G.M. Richards, M.D., at the University of British Columbia, studies in South America and the Philippines found that a 20 percent azelaic acid solution was equal to or better than 2 percent hydroquinone for treating melasma. Azelaic acid reduces the number of abnormal cells that produce melanin (called melanocytes) “by reducing the rate of DNA synthesis,” notes Dr. Todorov. Plus, azelaic acid may cause less skin irritation than hydroquinone.

• Kojic acid: Derived from fungus and fermented rice, kojic acid also inhibits melanin production, similar to hydroquinone, and may be just as effective. It's also a great solution for sensitive skin, according to Dr. Baumann. Kojic acid oxidizes quickly and will turn brown if left exposed to air. Check the expiration date and be sure to store kojic acid products in a cool, dark place, away from heat or light.

  Limited evidence has suggested safety concerns with kojic acid. In one study, when a strain of mice, who were already at risk for cancer, were fed large amounts of kojic acid for 26 weeks, they developed liver tumors, reports Dr. Todorov. He concludes that the impact on humans, “if any, remains unclear.”

• Licorice extract: A tyrosinase inhibitor, licorice extract is a potent skin lightener that disrupts skin’s melanin synthesis and also has anti-inflammatory qualities.

• Malic acid: An alpha hydroxy acid (AHA) derived from apples or pears, malic acid is an exfoliant. By sloughing off dead skin cells, it takes away extra pigment, too. As an AHA, malic acid can help “mottled pigmentation of photodamaged skin after months of daily application,” writes Heather Brannon, M.D., on About. But, like other AHAs, malic acid can cause irritation and skin sensitivity. Interestingly, AHAs may be able to correct photoaging and make skin more vulnerable to hyperpigmentation and discoloration at the same time, Dr. Brannon notes.

• Retinoids: These potent vitamin A-derivatives exfoliate dead surface skin cells, taking the hyperpigmentation with them. Plus, retinoids may reduce tyrosinase. Unfortunately, retinoids may not be as effective as hydroquinone, and can take longer to work. What’s more, retinoids can cause irritation and “may actually worsen pigmentation problems,” because retinoid-related irritation can cause a post inflammatory response, cautions Dr. Todorov. Another downside: Retinoids are notorious for causing sun sensitivity, which in turn makes skin more susceptible to additional hyperpigmentation.

• Vitamin C: The antioxidant vitamin C — also known as magnesium ascorbyl phosphate, ascorbic acid, ascorbyl glucosamine and ascorbyl palmitate — is a common ingredient in many botanical skin lighteners. Although studies have indicated that vitamin C inhibits melanin production at concentrations above 5 percent, most skincare products available over the counter aren’t quite this potent. So, for optimum results, use vitamin C in conjunction with other treatments.

Product picks

Hydroquinone alternatives are available in many formulas to suit your skin’s particular needs. Here are several options:

• Exuviance Skin Brightening Gel contains kojic acid, vitamin C, licorice, mulberry extract and bearberry extract to diminish discoloration. Use it on your face, neck and hands to encourage cell renewal and a brighter complexion.

• Donell Super Skin Lightening Gel features a blend of azelaic acid, kojic acid, vitamin C and lemon extract to improve hyperpigmentation.

• Caudalie Vinoperfect Radiance Serum is a velvety serum, designed to moisturize and fade uneven skin tone in as little as four weeks.

• DDF Organic Sunblock SPF 30 provides broad-spectrum UV protection to prevent sun damage and discoloration.

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