How safe is Hydroquinone? A Dermatologist Weighs in
Melasma, and hyperpigmentation in general, is one of the most common reasons people schedule an appointment with a dermatologist. Below, I’ll talk all about one of the most powerful topical ingredients we use to treat melasma, hydroquinone, and the safety concerns surrounding its use.
Okay, let’s dive into the topic at hand: just how SAFE is hydroquinone?
Hydroquinone is one of the most powerful topical ingredients when it comes to brightening dark spots, treating melasma, combatting hyperpigmentation and evening out skin tone. It’s available both as a prescription, often found in combination with other prescription medications like tretinoin, and is also available in OTC (over the counter) products. While it’s an incredibly powerful ingredient, and often considered first line by most dermatologists in the treatment of melasma, there are safety concerns surrounding its use. Does it get absorbed into the bloodstream? Can it cause cancer? Can it damage your liver? Should I be afraid to use it? Having researched this ingredient extensively, and having used it in the office for over a decade, I will give you my honest opinion here.
First, should you be afraid of systemic absorption, and possible risks associated with systemic absorption? Many people aren’t aware that they are being exposed to considerable amounts of hydroquinone in their diet every single day. Hydroquinone is found in nature as either hydroquinone or arbutin, which is converted into hydroquinone in the body. Hydroquinone and arbutin are found in tea, coffee, pears, wheat bread and red wine. Studies show that human exposure to hydroquinone from our diet is significant https://pubmed.ncbi.nlm.nih.gov/8568910/ I personally consume coffee and tea every day, and I love enjoying a juicy, ripe pear as a healthy snack.
Does hydroquinone cause cancer or damage the liver? Most of these studies were done in rats, and many were done on populations of rats that already had predispositions for growing certain cancers and tumors. Although I certainly am not going to ignore these concerning studies, it is very hard to make a convincing case that what we see in rats will translate into humans. As far as liver studies go, hydroquinone seems to actually have a slight protective effect when you look at risk for liver cancers in rats. So clearly, we really are not certain of the true impact that hydroquinone has on our different organs. So far, studies done in humans who are exposed to higher concentrations of hydroquinone have been reassuring. I honestly don’t know any board certified dermatologists in the US who are afraid to use this ingredient because of concerns surrounding its “toxicity” to the body, after having reviewed the literature and science extensively.
What we do know is that high concentrations of topical hydroquinone, especially used for long periods of time without a doctor’s supervision, can lead to a skin condition called exogenous ochronosis, or pseudo ochronosis.
This is when we see a darkening of the skin, even darker than the original melasma that these creams were meant to treat! Furthermore, it is near impossible to get these stains to disappear!
These cases, thankfully, are quite rare in the United States, and much more commonly found in parts of the world where people are also using antimalarial medications. Antimalarials also cause pseudo ochronosis, so the combination of hydroquinone plus antimalarials are probably a major risk factor for this condition.
The main risks seem to be:
using concentrations higher than 4%
using hydroquinone for years at a time without breaks, and
combining hydroquinone with other ingredients such as oral antimalarial medications.
We also know that many “bleaching” and “whitening” creams that you can find online or in other countries are contaminated with mercury and high potency steroids like clobetasol https://www.sciencedirect.com/science/article/abs/pii/S0013935116302651
Ok, so how do I approach hydroquinone in my office with my patients. Here are my take homes:
- Hydroquinone should only be used under the very strict supervision of a dermatologist
- Each patient needs to weigh pros and cons, risks and benefits of using hydroquinone vs using other treatment modalities. In cases where melasma is severe and affecting someone’s quality of life, the benefits may outweigh the risks. It’s a personal decision between that patient and the treating physician.
- If you have been prescribed a hydroquinone containing prescription from your dermatologist, you MUST follow up carefully. Most derms will rotate you off of hydroquinone every few months, to make sure you get prolonged breaks between uses.
- If you have used hydroquinone, or are using it, under the close supervision of a dermatologist, don’t lose sleep over it! Remember, everyone who is drinking coffee or tea, or eating pears or sipping on red wine, is also being exposed to hydroquinone.
- Do NOT try to get hydroquinone containing products online or through online pharmacies. If a friend brings you an extra “magic cream” across the border and swears by it, PASS! Warn your friend about mercury and clobetasol and other risks she/he might not even know about.