Is Hydroquinone Safe? We Asked Experts to Give Us the Facts

When it comes to skincare, there are a few ailments that require a tad more than TLC to combat (we're looking at you, dark spots, hyperpigmentation, and acne scars). Sure, the right skincare products are the first defense—an exfoliant, a brightening cream, and a vitamin C serum, for starters. However, even with consistent use of products that are regarded as high efficacy, it's possible a particularly stubborn spot will want to linger. That's when some people look to other remedies, like hydroquinone.

According to plastic surgeon David Shafer, MD, "hydroquinone is a chemical compound discovered in the early 1800s and was used in everything from skincare to photo developing. The chemical interacts with the melanin-producing cells in the skin, decreasing the production of pigment." While it can be effective at lightening dark spots on the skin, there's been some debate about hydroquinone's side effects.

Is hydroquinone safe, and does it pose any risk? We tapped into three other pros in addition to Shafer to get the full low-down: dermatologists Ava Shamban, MD, and Richard Bottiglione, MD, and cosmetic chemist Ee Ting Ng.

Though it may come with side effects, ultimately, there isn't definitive clinical evidence settling the debate about whether or not hydroquinone is harmful to humans. Still, like with all chemical ingredients, there's some gray area.

Keep reading to learn all about hydroquinone's side effects and benefits.

What Is Hydroquinone?

Hydroquinone is found in skin-lightening creams, serums, cleansers, and moisturizers. "Hydroquinone is a topical skin treatment for melasma, freckles, age and sun spots, and even acne scars," Shafer says. "Used in combination with other acne products such as Retin-A, it can help dramatically improve skin complexion." Shamban adds to this, reporting that hydroquinone can also be used to lighten up freckles as well as post-inflammatory hyperpigmentation, which is usually seen after an injury such as a burn or inflammatory acne.

While hydroquinone is effective at lightening spots, the results aren't immediate. It may take a matter of weeks (or months) before results are discernible to the naked eye. "Patients need to understand that the treatment is working at the cellular level to reduce the production of pigment," Shafer explains. "So the effects take several weeks to realize. As the old skin sheds and new skin is produced, the amount of pigment will be less, leading to a more even skin tone."

Benefits of Hydroquinone for Skin

Hydroquinone has several benefits for the skin.

• Lightens dark spots (hyperpigmentation): Hydroquinone is one of the most effective ingredients to lighten hyperpigmentation. "If you have dark areas from melasma, age spots, or brown spots left from acne, hydroquinone helps by decreasing the formation of melanin in the skin (the pigment in the skin that gives it a dark color)," says Buttiglione. Ng adds: "To date, hydroquinone is considered the topical gold standard in dermatology for reducing hyperpigmentation."
• Reduces acne scars: Because of its depigmenting properties, hydroquinone is a great choice for lightening acne scars and marks.
• Evens out skin tone: Because hydroquinone lightens certain areas of the skin that are darkened, the end result is a more balanced, even complexion.
• Fast absorbing: Unlike some skincare products, hydroquinone absorbs into the skin quickly, so you lose less product.
• Multiple forms of use: For skin-lightening purposes, hydroquinone is most often used topically, though it's available in oral supplements, as well.
• Treats post-inflammatory hyperpigmentation: Studies have found that hydroquinone can be used to treat post-inflammatory hyperpigmentation.
• Comes in a range of strengths: Creams that contain 2 percent or less hydroquinone are available to buy over the counter, but stronger creams are available with a prescription from a doctor—meaning you can build up your tolerance over time or find a strength to suit you.
• Treats melasma: "Hydroquinone serves as the backbone of any treatment for a wide variety of conditions, including melasma," notes Shamban. "Melasma, which is manifested by patches of darker skin typically on the forehead, cheeks, and upper lip, often runs in families and is triggered by UV and visible light exposure often in combination with hormonal shifts such as birth control pills, pregnancy, or hormone replacement therapy." Hydroquinone can help rectify the side effects of melasma.

Side Effects of Hydroquinone

You may have heard some questionable things about hydroquinone—it's even banned in the U.K., Europe, and Japan. Still, Shamban maintains that though it has had a bad rap, hydroquinone is not dangerous. "It is approved by the FDA and there aren't any research studies or clinical evidence to suggest that there is any [human] harm to using hydroquinone," she says.

That said, something this potent doesn't come without side effects—"halo spots" around the treated areas being one of them. "The hydroquinone treats dark spots, but any product in contact with surrounding skin will also lighten those areas as well," says Shafer. "So the intended spot may be lightened, but the surrounding skin will also lighten compared to normal skin, and the area will appear like a light de-pigmented halo around the spot being treated."

Ochranosis is also a common risk when hydroquinone is misused. According to research, ochranonsis is a condition that might occur following long-term application of skin-lightening creams containing hydroquinone. Ochranosis may actually cause darkening of the skin, instead of fading a particular spot. It's important to talk to your board-certified dermatologist about using hydroquinone to make sure your treatment strength and duration is safe.

If your skin skews sensitive, bear in mind that any topical cream is a potential allergen. "Hydroquinone frequently causes irritations like itchiness and redness in skins that are barrier-compromised or sensitive, which can be the case for any skin type," notes Ng. Shamban adds that "the most common side effects are irritation, redness, stinging, and inflammation."

How to Use It

"Over the years, I have never found a more effective treatment for unwanted pigmentation than glycolic acid and hydroquinone," says Bottiglione. "I recommend using hydroquinone after cleansing the skin with a glycolic acid cleanser, like the Dermatologist's Choice pH Balanced Cleanser with Glycolic Acid ($30)," says Bottiglione. "The key is to eliminate excess oil, dirt, and makeup that can block the hydroquinone from entering the pores. The deeper the hydroquinone can penetrate the skin, the better the benefits." And, while we all know the harmful effects of the sun on our skin, it can cause further darkening of spots, so using a UV-blocking sunscreen during the time you're using any hydroquinone product is a must.

"Most people don't need it all over the skin, just in particular areas," Bottiglione advises. "You should use it in the areas with hyperpigmentation." If you tend to be sensitive, Bottiglione recommends using it on alternating days, which can help the skin tolerate it better. "Using an over-the-counter option at a low concentration can help the skin tolerate it better as well," he notes.

"I usually recommend evening before bedtime as I like to use the cellular regenerative hours overnight for the product to get to work," says Shamban. Also, Ng notes that hydroquinone makes skin more susceptible to UV damage and that insufficient sun protection during treatment can lead to the development of more hyperpigmentation—always ensure your skin is protected while donning a hydroquinone treatment.