Hydroquinone is a skin-lightening agent. It bleaches the skin, which can be helpful when treating different forms of hyperpigmentation.

Historically, there’s been some back-and-forth on the safety of hydroquinone. In 1982, the U.S. Food and Drug Administration recognized the ingredient as safe and effective.

Several years later, concerns about safety prompted retailers to pull hydroquinone from the market. The FDA went on to discover that many of the products in question contained contaminants like mercury. They established that these contaminants were behind reports of adverse effects.

Since then, the FDA has confirmed that hydroquinone can be safely sold over the counter (OTC) in 2 percent concentrations.

Read on to learn more about how it works, who might benefit from use, products to try, and more.

Hydroquinone bleaches your skin by decreasing the number of melanocytes present. Melanocytes make melanin, which is what produces your skin tone.

In cases of hyperpigmentation, more melanin is present due to an increase in melanocyte production. By controlling these melanocytes, your skin will become more evenly toned over time.

It takes about four weeks on average for the ingredient to take effect. It may take several months of consistent use before you see full results.

If you don’t see any improvements within three months of OTC use, talk to your dermatologist. They may be able to recommend a prescription-strength formula better suited to your needs.

Hydroquinone is used to treat skin conditions related to hyperpigmentation. This includes:

Although hydroquinone can help fade red or brown spots that have lingered, it won’t help with active inflammation. For example, the ingredient can help minimize acne scarring, but it won’t have an effect on redness from active breakouts.

Although hydroquinone is generally well-tolerated, there are a few exceptions.

If you have dry or sensitive skin, you may find that hydroquinone causes further dryness or irritation. This usually tapers off as your skin adjusts to the ingredient.

People who have normal or oily skin are less likely to experience these side effects.

The ingredient tends to work best on fair skin tones. If you have a medium-to-dark skin tone, talk with your dermatologist before use. Hydroquinone may actually worsen hyperpigmentation in darker skin tones.

Consistency is key to treating hyperpigmentation. You’ll want to use this ingredient every day for maximum results. Follow all product instructions carefully.

It’s important to do a patch test before your first full application. This will allow you to determine how your skin will react and whether it results in unwelcome side effects.

To do this:

  • Rub a small amount of the product into the inside of your forearm.
  • Cover the area with a bandage.
  • Wash your hands to prevent the product from staining your clothes or other materials.
  • Wait 24 hours.
  • Discontinue use if you experience severe itching or other irritation during this time.

If you don’t experience any side effects, you should be able to safely add it to your skin care routine. You should apply it after cleansing and toning, but before your moisturizer.

Take just a small amount of the product and apply it evenly across the entire area of skin. Gently massage into your skin until it’s completely absorbed.

Make sure you wash your hands after use — this will prevent the product from affecting other areas of skin or staining your clothes and other materials.

You should also wear sunscreen while using this ingredient. Sun exposure can not only make hyperpigmentation worse, but also reverse the effects of your hydroquinone treatment.

Sunscreen is usually the last step of a skin care routine. Be sure to reapply as needed throughout the day.

While consistency is important for maximum results, you shouldn’t use it for long periods of time. If you don’t see any improvement after three months, discontinue use.

If you do see improvement, you can use the product for up to four months, and then begin to taper off use. You shouldn’t use it for more than five months at a time.

If you want to begin using the product again, wait two to three months before you resume use.

To date, hydroquinone is deemed safe in the United States. There isn’t any clinical evidence currently to suggest that hydroquinone is harmful to humans.

However, minor side effects are still possible. It may cause a temporary uptick in redness or dryness at first, especially if you have sensitive skin. These effects should fade as your skin becomes used to the product.

In rare cases, hydroquinone has caused a condition called ochronosis. It’s marked by papules and bluish-black pigmentation. This can occur after prolonged daily use. As such, you shouldn’t use products with this ingredient for more than five months at a time.

OTC products typically combine hydroquinone with other skin-lightening ingredients to produce maximum benefits.

Popular options include:

Higher concentrations and pure forms of hydroquinone are only available with a prescription.

If you’d rather not use a chemical agent like hydroquinone, natural skin-lightening products are available.

These typically include one or more of the following:

  • Antioxidants. Vitamins A and C are commonly used in anti-aging products to brighten the skin and improve your overall tone. When used over time, antioxidants may also help lighten areas of hyperpigmentation.
  • Plant-based acids. Contrary to popular belief, acids aren’t always chemically based. Many acids in skincare products are actually derived from plants. For hyperpigmentation, you might try kojic or ellagic acids. These work by slowing down your skin’s melanin production.
  • Vitamin B-3. Commonly labeled as “niacinamide,” this ingredient has the potential to prevent darker areas of pigmentation from rising to the surface of your skin.

Hyperpigmentation can be a difficult condition to treat. Although hydroquinone may help lighten your skin, this ingredient isn’t appropriate for everyone.

You should check with your dermatologist before use, especially if you have sensitive skin or a medium-to-dark skin tone. They can advise you on how you should use this ingredient, if at all.

They can also recommend alternative skin-lightening treatments, including natural products and chemical peels.

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