Skincare with Friends Episode 56: Hydroquinone Myths: Does it cause cancer? Will it bleach the skin? Does it cause darkening of the skin?…

Another lockdown Zoom podcast, but it felt like a mega treat to chat to a friend about a topic close to both our heart- Melasma and it’s treatment with Hydroquinone. We get our Hydroquinone from Dermatica (not sponsored, no money changes hands but Dermatica gives me my subscription for free because I keep banging on about them) and use it under the strict direction on a dermatologist which is the way it should be. Use my Dermatica code NIAP1 for a free month and 20% off your second month (FYI I don’t get paid if you do, my recommendation is genuine).

Hydroquinone is surrounded by controversy for a few reasons. It was banned from over the counter sale because of concerns about cancer, bleaching, hypopigmentation and worsening of melasma. It’s largely good news about Hydroquinone, it’s not as bad as they’ve made it out to be. We went through all the scientific studies to sort out what is real from what is alarmist nonsense and sales bullshit from HQ free shills. To listen the podcast search “Skincare with Friends” into your usual podcast provider. Or read what we have to say here-

Hydroquinone is the gold standard for treating melasma, it is only available in the UK on prescription and in the USA only concentrations of up to 2% are available OTC. It is controversial because of it’s FDA ban due to worries that it might cause cancer. It works well, usually takes 2-3 months to remove pigmentation, but it is irritating and the pigmentation returns when you stop using it. There are other options (like tretinoin, azalea acid, niacinamide, vitamin C, chemical peels and laser) but nothing works as well as hydroquinone.

Does Hydroquinone cause cancer? Potentially

The concern comes from the fact that Benzene is metabolised into Hydroquinone and Benzene is a known cancer causing agent, so it’s closely related to a cancer causing molecule. There was a study on rats that showed the potential for hydroquinone to cause renal adenomas, the rats were fed huge doses of HQ. Since that 1992 study, there has been a lot more research on animals and humans that found no evidence of malignancy in vivo tests (tests simulating real life conditions).

It is worth noting that hydroquinone has been manufactured and used for over 50 years and no cases of skin cancer or internal malignancy related to the topical application of hydroquinone have been reported. All the evidence we have shows that it is safe to use topically for melasma.

We believe that the difference in results between the lab and the real life experiments is because we are actually exposed to HQ all the time in food and our bodies have evolved to process it in the liver. Common foods ingested daily by most individuals have significant quantities of naturally occurring hydroquinone and/or arbutin-

• Cranberries and blueberries. 
• Coffee and tea represent a significant source of hydroquinone.
• Red wine.
• Rice and onions contain intermediate amounts.
• Hydroquinone/arbutin are found in wheat germ, wheat and wheat bread
• One pear can contain 620 μg hydroquinone/arbutin. Pear skin in particular has large quantities of hydroquinone or arbutin.

“On the other hand, there are no adequate epidemiological data to definitely document that hydroquinone is not carcinogenic in a rare individual. The results from studies on occupational exposure suggest that those exposed to significant quantities of this chemical in fact exhibit lower rates of illness and cancer than control populations. Benzene, by contrast, is a very dangerous substance and causes marrow toxicity is high percentages of exposed individuals depending on the dose.”

Nordlund et al, 2006

References:

Nordlund et al (2006) “The safety of hydroquinone” J of European Academy of Dermatology and Venereology  

Kari FW, Bucher J, Eustis SL et al. Toxicity and carcinogenicity of hydroquinone in F344/N rats and B6C3F1 mice. Food Chem Toxicol 1992; 30: 737–747.

Does Hydroquinone Bleach the Skin? No

Whitening agents like HQ work in a number of different ways. But mainly they generally slow down melanin production.

Most treatments for hyperpigmentation act on the first step of melanin synthesis – the conversion of tyrosine into DOPA and dopaquinone by an enzyme called tyrosinase. Hydroquinone blocks the enzyme tyrosinase and competes with tyrosine to prevent it’s eventual conversion into melanin, rather than taking the colour out of the skin.

“How does it lighten just the hyperpigmentation? I mean do you just target the affected area when you’re applying?- Hydroquinone competes with tyrosine in the production of melanin, which means that it reduces melanin production, rather than removing the melanin. It hasn’t got such a strong effect that it stops melanin from being produced, it just reduces the amount of melanin. So the cells that are really chucking the pigment out have their action reduced, creating an even playing field in terms of pigment production”

Nat + Nia, Skincare with Friends podcast

However, Destruction of melanocytes is not a myth and I wasn’t aware of this! HQ can react with oxygen to form hydroxybenzoquinone, which can kill the cells that make melanin and therefore can bleach skin. So gone off hydroquinone can cause depigmentation. Throw your HQ away if it starts to yellow and always use HQ in airtight containers. 

Could Hydroquinone Make my Skin Darker?

Will Hydroquinone cause my skin to turn black?

There is a condition called Exogenous Ochronosis which gives the skin a dark blue grey colour. I wanted to know about how common this condition actually is, I’ve never heard of anyone having suffered it in any of the skincare groups I’m in.

Ochronosis looks darker than melasma, and if you suspect you might be suffering with it, it’s best to head to a derm for early diagnosis. It happens when the HQ accumulates in the skin over a long period of time and polymerises into homogentisic acid. It isn’t easy to treat, the best treatment option we have is laser.

Exogenous Ochronosis was thought of as a condition only seen in darker-skinned individuals of Africa; however, the condition has been shown to occur in persons of Hispanic, Asian, and Caucasian descent.

In a 2015 review study, the number of cases of EO reported in the US was determined to be 37 from 1983 to 2014. A survey conducted by the Department of Health and Human Services, which was completed by 2080 US dermatologists, reported 512 suspected cases in total, as diagnosed in clinics and hospitals by dermatologists. Ochronosis is likely to be more prevalent in Asia and Africa but we don’t have solid data on that.

Simmons et al, 2015

Labmuffin thinks that it is the other ingredients in controversial skin whitening formulas that increase this risk, rather than the HQ itself eg: mercury compounds. 

Ochronosis appears to be a rare condition but it’s best to use Hydroquinone under the supervision of a dermatologist using approved formulations in airless containers to prevent oxidation, no dodgy lightening creams from eBay.

Reference:

Simmons et al 2015 “Exogenous Ochronosis: A Comprehensive Review
of the Diagnosis, Epidemiology, Causes, and Treatments” American Journal of Clinical Dermatology

Should People of Colour Avoid Hydroquinone?

No! As we said above, the Hydroquinone reduces the amount of pigmentation from hyperactive melanocytes rather than bleaching the skin it is safe for Fitzpatrick III and up. It won’t lighten skin or cause depigmented patches AS LONG AS IT’S ALWAYS USED FRESH, chuck your HQ as soon as it yellows. Studies have shown that dark skin types have used HQ successfully to treat hyperpigmentation and melasma.

Other Options- Hydroquinone Free Treatments for Melasma

Nothing has the wealth of evidence of Hydroquinone when it comes to reducing pigmentation, but here are some options to explore. Read my guide to treating melasma using The Ordinary–

• Alpha Arbutin- closely related to hydroquinone, has a much slower action, less risk of Ochronosis, deemed safe to use continuously
• Azelaic acid
• Vitamin C and Magnesium Ascorbyl Phosphate
• Tretinoin (good for sooo many skin issues)
• Niacinamide
• Cyspera aka Cysteamine
• Oral and topical Tranexamic acid
• Kojic acid
• Liquorice
• Laser and IPL

Other tips to treating melasma with skincare- also focus on whole body health, reducing stress, having a good diet, wearing spf on a daily basis, keep skin healthy and hydrated and avoid fragrance. See below for product recs.

Take Home Message

Hydroquinone is safe under the direction of a dermatologist. As long as you’re using it properly- taking breaks and disposing of it when it starts to turn yellow/when it hits it’s use by date, you’ll be fine. Never buy it from dodgy sellers. Hydroquinone doesn’t cause cancer and used properly is highly unlikely to cause bleaching or darkening of the skin. Give the podcast a listen, we explain things in a much funner way-

Products We Mentioned in the Podcast

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