What Is Hydroquinone?

If you’ve used or researched skin lightening products, there’s a good chance you’ve encountered hydroquinone. This substance has long been used to treat hyperpigmentation problems, due to its ability to lighten skin pigment. Recently, however, it’s been making headlines for doing exactly the opposite.

It’s called rebound hyperpigmentation, or ochronosis. It occurs when a resistance builds up to a particular substance due to chronic use. This not only renders the substance ineffective, but can actually cause it to have the opposite intended effect.

Hydroquinone has been a popular choice to treat common hyperpigmentation problems such as melasma, chloasma, and postinflammatory hyperpigmentation. When used in safe doses under physician care, the results have been very positive. Then, the internet happened. With products containing hydroquinone became widely available online, people began opting to skip the doctor’s office and consultation fees, and buy directly from online sources—often ones with the cheapest price tag and no qualifications. The problem wasn’t even the use of discredited hydroquinone products, it was the duration at which people used the products.

The continued use of any medical-grade skincare product without the advice of a physician is a bad idea, plain and simple. It’s even worse if the product wasn’t prescribed to you in the first place. While many doctors believed hydroquinone was perfectly safe for treating hyperpigmentation, the negative effects of prolonged use have caused many of them to discontinue using it at all.


One of the reasons prolonged use of hydroquinone can cause more harm than good has to do with resistance. Even people who have used hydroquinone in the proper concentrations and under the care of a physician still saw adverse affects after extended use of the product. These manifested after four or five months of continued use. The early signs looked like the hydroquinone just wasn’t effective anymore; then areas around the dark spots continued to brighten while the melasma stayed the same, or actually began to darken. This is because the melanocytes, the cells responsible for producing melanin, began to resist the hydroquinone and became overactive.


Another reason deals with photosensitivity. Also known as phototoxicity, this refers to increased sun sensitivity. Many common skincare ingredients are known to cause photosensitivity, such as retinoids. When products containing these agents are prescribed, a warning about increased sun sensitivity is also given, so the user is very cautious about sunscreen application and covering up while outdoors. However, no one thought hydroquinone fell into this category, so those using hydroquinone were not aware of their increased sun sensitivity. As hydroquinone decreases skin melanin, which is responsible for giving pigment to the skin, we become more susceptible to harmful UV radiation. With increased sun sensitivity our skin becomes inflamed, leading to increased melanin production, or rebound hyperpigmentation. The sun can also affect melanocyte production directly, which can cause a warped melanin production with a blue hue that causes ochrosis. This is extremely difficult to treat because the pigment issues are very deep in the skin.

Concentration & Combination

Two other main problems are high concentrations and combination formulas. Using anything higher than hydroquinone 4% has been noted as causing resistance at a much faster rate. This is because high concentrations can shock melanocytes into rapidly increasing melanin production. It could also cause inflammation of the skin, leading to rebound hyperpigmentation. Many products are also combining hydroquinone with other topical agents such as Vitamin C, retinoic and glycolic acid, and topical steroids. Using combination products is dangerous because certain ingredients are only effective in certain environments. For example, a common combination is hydroquinone and topical steroids, because topical steroids suppress inflammation caused by the hydroquinone. But because topical steroids are only affective on pigmentation problems caused by trauma (post-inflammatory hyperpigmentation), someone using such a product to treat hyperpigmentation due to melasma will not see the desired results. These combination products should only be used for a duration of one week, but many users are continuing them far beyond this span.

So, what does this mean for you?

If you’re using hydroquinone without the supervision of a physician, stop immediately and go for a consult. If you’ve been using hydroquinone continually for over four months, there is a chance you could develop a resistance. The best practice is to discontinue use after four months, and switch to an alternate bleaching agent for three months. This gives your melanocytes time to stabilize, and your melanin time to restore its natural balance.

If you’re using hydroquinone or products containing it, it’s vital to use sun protection. Wear a SPF of 30 or higher, and reapply often. Direct sun exposure is highly discouraged. If you’re using a concentration of over 4% without strict physician supervision, consider stopping entirely or seeking professional advice before continuing.

It’s important to know where the product you’re using is coming from. Whether you buy it online or in stores, make sure the product is genuine and contains the proper ingredients. Be especially wary of buying online from places like Ebay, as many of the sellers are selling off-brand products of low quality.

Our ultimate recommendation is to seek a professional before starting or continuing hydroquinone use. Although it remains an effective ingredient for treating hyperpigmentation problems, due to its known adverse affects, it should be used only under the strict supervision of a professional. Keep in mind that in most cases of rebound hyperpigmentation due to extended hydroquinone use, the patient began using hydroquinone under the care of a professional. Their issues arose when they did not return for follow up treatment, and kept using the skin regime that was initially prescribed for a period of time not dictated by their doctor. These patients also turned to online sources to obtain products after they discontinued seeing their doctors.

So follow your physician’s orders, and return for frequent checkups. Never buy products online from unreliable sources, and never start or continue a regime without the advice of a trained professional.

If you have any concerns about hydroquinone use, or are struggling with hyperpigmentation, place contact our clinic for a free consultation. You can book online here, or by calling toll free 1-888-520-2929.