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Hydroquinone: Everything you need to know about this hyperpigmentation-fighting ingredient

Help kick dark spots to the curb with this powerhouse skincare ingredient.

Curology Team Avatar
by Curology Team
Updated on Jul 6, 2023 • 8 min read
Medically reviewed by Kristen Jokela, NP-C
face body cream balm
Curology Team Avatar
by Curology Team
Updated on Jul 6, 2023 • 8 min read
Medically reviewed by Kristen Jokela, NP-C
We’re here to share what we know — but don’t take it as medical advice. Talk to your medical provider if you have questions.

Though super common,hyperpigmentation can be frustrating to deal with. Maybe your time in the sun left you speckled like a week-old banana, or perhaps you’re experiencing a change in hormones that is causing brown patches to appear on your face. Whatever the reason, we feel you. There are many treatment options for hyperpigmentation, ranging from simple daily sunscreen use to in-office laser treatments, but today’s spotlight is on one particular topical ingredient: hydroquinone.

At Curology, we value transparency—so before we dive into the nitty-gritty, we’d like to address the background of hydroquinone. There is some controversy around this ingredient that comes from the historical trend of skin-lightening or bleaching, which was driven by racist beauty ideals prizing light skin. Its misuse as a skin lightener or “bleach” stems from unjust, biased beauty ideals, which the media has historically promoted.¹ Generally, dermatology providers and medical experts agree that using hydroquinone to lighten overall skin tone is a misuse, and they do not advise using it in this way.

That said, hydroquinone is generally safe to use and is one of the most effective ingredients for treating hyperpigmentation, as long as it’s used responsibly and as directed.

How does hydroquinone work?

Hydroquinone works for hyperpigmentation by acting as a tyrosinase inhibitor. We know that’s a mouthful, so let us explain.

First, here are some important terms:

  • Melanin: Melanin is the natural pigment in our skin.

  • Melanocytes: Melanocytes are the cells in our skin that produce melanin.

  • Tyrosinase: Tyrosinase is a protein needed to make melanin from melanocytes.

This means that hydroquinone stops your skin from making new pigments by blocking the melanocytes from making more melanin.²

Melasma Image - The different types of hyperpigmentation

What is hyperpigmentation?

Hyperpigmentation is a skin condition in which there are areas of the skin where too much melanin, or pigment, is present.³ Common among people of all ages and skin types, hyperpigmentation refers to skin that appears darker than the surrounding skin. This increased pigmentation isn’t harmful and can cover large or small areas of the body, or even the entire body. 

Types of hyperpigmentation include the following: 


Melasma, which may occur during pregnancy, is often triggered by hormonal changes. It’s most often seen on the cheeks, chin, and forehead. UV radiation, hormonal fluctuations, genetics, antiepileptic medications, and having darker skin may increase your risk of developing melasma. You may also be more likely to develop this condition if you’re pregnant or taking oral contraceptives.⁴ 


Also called solar lentigines, age spots, or liver spots, these dark spots are the result of prolonged sun exposure. They’re seen most frequently on areas of the body often exposed to the sun, such as the face and hands. Small, flat, and seen in varying shades of light tan to dark brown, sunspots are considered one of the signs of aging, like fine lines.

Post-inflammatory hyperpigmentation (PIH)

Those dark marks left behind when you pick at a pimple? That’s PIH. This type of hyperpigmentation can result from any inflammation or injury to the skin, including acne, which in turn causes increased melanin production.⁵ 

What does hydroquinone help treat?

Hydroquinone can lighten dark areas of the skin, making it an effective treatment for all types of hyperpigmentation. Simple to use, your dermatology provider may prescribe it in the form of creams, lotions, gels, or emulsions, to use for a specified period. To ensure the best results, always follow the directions. 

When it comes to the types of hyperpigmentation we mentioned earlier, here’s how hydroquinone can help: 

  • Melasma: Hydroquinone is a commonly prescribed treatment for melasma and is widely considered effective by dermatology providers. Some dermatology providers suggest combining hydroquinone treatment with additional active ingredients, including topical steroids and prescription retinoids like tretinoin. Your dermatology provider may also recommend combining hydroquinone with an over-the-counter retinol cream.⁶

  • Sunspots: Hydroquinone is a standard treatment for sunspots. You can help reduce the risk of sunspots from sun damage by not forgetting your sunscreen and avoiding spending time outdoors when the sun is at its strongest (10 am-4 pm). 

  • Post-inflammatory hyperpigmentation (PIH): PIH is the dark marks left behind when skin injuries like breakouts and other types of inflammation heal. To treat PIH, your dermatology provider may prescribe a hydroquinone cream to use up to twice daily for a limited period of time. They may also recommend that you use a retinoid ( vitamin A derivative) alongside hydroquinone.⁷

When using hydroquinone to treat hyperpigmentation, always wear your SPF! Exposure to the sun can reduce or reverse the effects of this active ingredient. Our experts suggest using a broad-spectrum sunscreen with SPF 30 or higher.

Skincare products to treat hyperpigmentation

When used responsibly, hydroquinone is one of the most effective ingredients when treating hyperpigmentation. So if you’re looking to treat hyperpigmentation by adding this ingredient to your skincare routine, Curology’s personalized, prescription formulas are arguably one of the easier ways to get effective ingredients to help fade dark spots.

How should hydroquinone be used?

Hydroquinone is a topical medication used to lighten hyperpigmented areas (like sunspots). It’s available with a prescription from your medical provider. A thin layer should be applied to dark spots and patches with the fingertips. Some dermatologists and dermatology providers suggest using a Q-tip if there are only a few dark spots or the spots are smaller in size.

Another important tip: Hydroquinone should only be used consistently for a few months, followed by a break period of another few months.⁸ If you’re using a prescription-strength hydroquinone product, your medical provider will provide the specific “on-time” and “off-time.”

And don’t forget sun protection! Dark spots can get worse from sun exposure, so it’s essential to be consistent with sunscreen while using hydroquinone (and treating dark spots in general).

What are the possible side effects of hydroquinone?

Most people respond well to hydroquinone, so the best thing you can do for your skin is to follow your healthcare professional’s instructions—though some people may experience temporary mild irritation when used in higher concentrations,⁹ so be sure to let your provider know if you experience any concerns with use. 

Ochronosis, another possible (but rare!) side effect, is a gradual blue-black or gray-blue darkening of the skin that is rarely seen after prolonged use of hydroquinone, especially at high concentrations.¹⁰ It’s also important to note that there are other potential unwanted effects besides these (learn more about them here).

Hydroquinone during pregnancy: Is it safe?

woman touching her pregnant belly

Pregnancy is an exciting time in your life, but it has some restrictions! From sushi to deli meats, certain things aren’t pregnancy-safe, including some skincare ingredients

Hydroquinone is not safe to use during pregnancy. Wondering why? The Food and Drug Administration assesses the safety of substances for use by pregnant and nursing women and assigns each substance a pregnancy category rating based on their research. The scale runs as follows: A, B, C, D, and X. Substances labeled A or B are considered safe for people who are pregnant or nursing, and substances labeled C, D, or X are deemed unsafe. 

Hydroquinone is a pregnancy category C substance;¹¹ research shows adverse side effects on animal fetuses, and human research is lacking. It’s up to you and your doctor to discuss the implications of hydroquinone use during pregnancy, while nursing, and while trying to conceive. However, we strongly recommend avoiding it due to the potential risks.

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What else does hydroquinone treat?

Hydroquinone is used to treat a range of additional conditions. These include poikiloderma,drug-induced hyperpigmentation, which can occur due to chemotherapy agents, and folliculitis barbae,¹² which are itchy, sore hair follicles in areas where you shave often.¹³ Hydroquinone may also be used before chemical peels and laser treatments.

• • •

P.S. We did the homework so you don’t have to:

  1. Darj, E., Infanti, et al. (2015). "The fairer the better?" Use of potentially toxic skin bleaching products. African health sciences. (2015).

  2. Ngan, V. Hydroquinone. DermNet NZ. (2005.)

  3. Wang, R. F., et al.Disorders of Hyperpigmentation. Part I. Pathogenesis and clinical features of common pigmentary disorders. Journal of the American Academy of Dermatology. (2022).

  4. Schwartz, C., et al. Hydroquinone. StatPearls. (2022).

  5. Chaowattanapanit, S., et al. Postinflammatory hyperpigmentation: A comprehensive overview: Treatment options and prevention. Journal of the American Academy of Dermatology. (2017).

  6. Bandyopadhyay, D., Topical treatment of melasma. Indian J Dermatol. (2009).

  7. Chandra, M., Levitt, J., Pensabene, CA., Hydroquinone therapy for post-inflammatory hyperpigmentation secondary to acne: not just prescribable by dermatologists. Acta Derm Venereol. (2012).

  8. Schwartz, C., et al, Hydroquinone. Ibid.

  9. Ngan, V. Hydroquinone. DermNet NZ. (2005)

  10. Schwartz, C., et al, Hydroquinone. Ibid.

  11. Schwartz, C., et al, Hydroquinone. Ibid.

  12. Ngan, Vanessa.,Hydroquinone. DermNet NZ. (Ibid.)

  13. Oakley, A., et al,Folliculitus barbae. DermNet NZ. (Ibid.)

Kristen Jokela is a certified Family Nurse Practitioner at Curology. She obtained her Master of Science in Nursing at the University of South Florida in Tampa, FL.

This article was originally published on May, 17 2021, and updated on November, 28 2022.

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• • •
Our medical review process:We’re here to tell you what we know. That’s why our information is evidence-based and fact-checked by medical experts. Still, everyone’s skin is unique—the best way to get advice is to talk to your healthcare provider.
Curology Team Avatar

Curology Team

Kristen Jokela, NP-C

Kristen Jokela, NP-C

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