How hydroquinone works for your complexion

The skin-brightening ingredient that hones in on dark spots

A word about your dark spots: sunscreen might be your longtime ally when it comes to preventing them, but hydroquinone might just be your skin’s new best friend when it comes to actively treating dark spots. Even taking the most scrupulous preventative steps (we’re talking full-brimmed hats and sunscreen on repeat) can’t guarantee that you’ll be in the clear with dark spots. Treating dark spots requires an extra level of attention––and that’s where hydroquinone comes in, the gold standard of dark spot treatments. 

What is hydroquinone?

Hydroquinone is a depigmenting agent. Your skin produces pigment called melanin, which gives color to your skin (as well as your hair and eyes). Those dark spots on your face or other parts of your body, also known as hyperpigmentation, are basically the result of your skin overproducing pigment 1. Melasma is a form of hyperpigmentation that can be triggered by several factors: sun exposure, pregnancy, even birth control pills (just to name a few!). Hydroquinone can help fade dark spots by blocking the production of pigment.

Historical context on hydroquinone

Ingredients like hydroquinone have been misused due to trends of “skin-lightening” and “skin-bleaching.” These trends stem from racialized standards of beauty prizing lighter skin, and still exist today 2. Hydroquinone is meant to help fade dark spots, and dermatologists and medical experts agree that using ingredients like hydroquinone to change overall skin tone is misuse. Here at Agency, we’re not only committed to personalizing research-backed ingredients for your skincare routine––but also to celebrating your unique skin.

How does hydroquinone work?

Let’s dig deeper into the science behind hydroquinone. Dark spots are the result of an overproduction of melanin, but how is melanin made? Melanocytes are the specialized cells in our skin that make melanin, and within the melanocyte is an enzyme called tyrosinase that kick starts melanin production 3. Hydroquinone gets to the root of the issue by inhibiting tyrosinase, meaning it stops your skin from making more melanin.4

How to use hydroquinone

Hydroquinone is used topically to help improve the appearance of certain types of hyperpigmentation, such as stubborn sunspots and dark spots leftover after a breakout. You can get it with a prescription from your medical provider, like your Agency dermatology provider. A thin layer should be applied to areas of hyperpigmentation, either with a Q-tip if you have smaller dark spots or with the fingertips if you have larger patches or clusters. 

Using hydroquinone comes with its own special rhythm: an “on” time to use hydroquinone consistently and an “off” time to temporarily stop using it. Prolonged use of hydroquinone may lead to permanent skin coloration (as they say, “too much of a good thing…”), which is why it’s important to take a break from it.

If your Agency Dark Spot Formula contains hydroquinone, your Agency provider will provide the specific “on” and “off” times for your treatment. We’ll send you a Dark Spot Formula with hydroquinone followed by a formula without hydroquinone (which will still contain active ingredients that target dark spots).

How long does it take hydroquinone to work?

As is generally the case with skincare products, results vary from person to person. That said, many start seeing their dark spots lighten after about 8-12 weeks of using hydroquinone. Hydroquinone shouldn’t be your lone dark spot product, though––remember that the best way to prevent dark spots in the first place (and prevent them from returning) is by applying and (reapplying!) sunscreen.

What are the possible side effects?

More good news about hydroquinone: besides being an all-star ingredient when it comes to helping take care of your dark spots, most people respond well to it. Our best advice is to follow your Agency provider’s instructions for use and be mindful of any irritation, itching, rashes, or allergic reactions. We’ve got tips to help ease irritation, and if your side effects aren’t going away or are more significant than mild, reach out to your Agency provider. There are other potential side effects (detailed here), but those tend to be less common. Ochronosis, for example, is rare––it’s the gradual darkening of skin to blue/black or gray/black and typically only happens after prolonged use of hydroquinone, especially at high concentrations.5

Want to know more about your Dark Spot Formula?

You know your skin—we’re here to help you know your skincare. Our team of dermatology experts has helped create guides to each of the hyperpigmentation-targeting ingredients in your Dark Spot Formula

Learn how azelaic acid, hydroquinone, and kojic acid also help your skin face the future.



1. Erica C Davis, Valerie D Callender. Postinflammatory hyperpigmentation: a review of the epidemiology, clinical features, and treatment options in skin of color. The Journal of clinical and aesthetic dermatology. (2010).

2. Elisabeth Darj, et al. The fairer the better?. Use of potentially toxic skin bleaching products. African Health Sciences. (2015, December).

3. Schlessinger, DI. et. al. Biochemistry, Melanin. StatPearls [Internet]. (2020).

4. Chelsea Schwartz, et al. Hydroquinone. StatPearls [Internet]. (2020, Jan.)

5. Chelsea Schwartz, et al. Hydroquinone. StatPearls [Internet]. (2020, Jan.)