Archive for December, 2012
Hydroquinone has been the gold standard for treating hyperpigmentation for over 50 years, but some confusion about hydroquinone has developed over the past few years. Common rumors include, hydroquinone has been banned or that it causes cancer. A lot of information found on the internet misrepresents hydroquinone by omitting some of the facts related to Hydroquinone studies and the FDA’s proposed rule.
I personally use hydroquinone on my skin to treat melasma and hyperpigmentation. I love what hydroquinone does for my skin and I have not been able to duplicate the results with other skin lighteners, however health is always going to outweigh the benefit of beautiful skin. I certainly would not want to use anything that is unsafe, furthermore I consider my self an advocate for my clients. It is important that my clients feel confidant in my knowledge of skin care and even more important that they trust that I always have their best interest in mind. I have spent a lot of time educating my self on hydroquinone and I aim to clarify some of the confusion.
What is Hydroquinone
Hydroquinone is an active ingredient used in topical creams and cosmetics as a depigmenting agent to treat skin discoloration such as melasma. Topical skin lightening creams containing Hydroquinone first became available in the United States in 1955. Hydroquinone has been described as a ubiquitous chemical, meaning it is something that we are exposed to as part of our daily life. Hydroquinone occurs in some plants as free hydroquinone or as arbutin. Arbutin (glucosylated hydroquinone) is found in the leaves and fruits of many plants that are used for food and bacteria in the intestines can transform it into hydroquinone. Hydroquinone and Arbutin can be found in foods such as cranberries, blueberries, pears, beans, broccoli, onions tea, coffee, beer, red wine, all-wheat bread and cereals (concentration may exceed 1%). Hydroquinone also has a number of other uses, it is used as an antioxidant for rubber, a reducing agent for photographic developing solutions, a stabalizer in paints and varnishes. It is also found in hair dyes and nail polish. The list goes on and on.
Does Hydroquinone Cause Cancer
Hydroquinone has been available as active ingredient for over 50 years and there have not been any reported cases of hydroquinone induced cancer in humans. There is also no evidence in human clinical studies to suggest that Hydroquinone could cause cancer in humans. It is suggested that additional studies are needed.
What about the Rats? I have heard and read many times that hydroquinone causes cancer in rats, so I decided to read the study and reviews myself. The 2 year gavage study with hydroquinone, showed some Rats with end stage CPN developed cancer. The problem is that you need to read the full report and it’s reviews before you develop a conclusion. CPN is a renal disease that affects various strain of rats, but has no counterpart in humans. In a 2007 review, McGregor concluded that hydroquinone is carcinogenic only in the context of end-stage CPN, which is not relevant in humans. There is some debate over using rats in carcinogenicity studies, as test results may not be relevant to humans. It should be noted that certain strain of rats are prone to spontaneously develop tumors.
Does Hydroquinone Cause Ochronosis
There are two types of ochronosis, endogenous and exogenous. It is only exogenous ochronosis which can be induced by the topical application of compounds including hydroquinone as well as antimalarias, mercury, resorcinol and phenol. Exogenous ochronosis is a fairly rare type of dermatitis that needs to be diagnosed by a dermatologist. It is not known exactly how hydroquinone induces ochronosis but suggested factors include: sun exposre, long term use of hydroquinone, high concentrations of hydroquinone, other active derivatives and penetrating vehicles such as t-butyl alcohol, mercuric compounds, resorcinol and hydroalcoholic lotion. Exogenous ochronosis is believed to be a progressive disorder that likely develops over several years.
Was Hydroquinone Banned
No, hydroquinone was not “banned” in the US. Hydroquinone is available in concentrations of 2% or less over the counter (OTC), and concentrations over 2% (typically 4%) are available in prescription strength in the United States.
To simply say Hydroquinone has been “banned” in other countries is something of a misrepresentation. First, we need to acknowledge that hydroquinone is an active ingredient available in prescription strength and over the counter (OTC) strength. I am not aware of any ban or proposed ban on prescription strength hydroquinone in any country. The confusion seems to come from the change in availability of over the counter (OTC) hydroquinone. In Japan and Australia hydroquinone is no longer available in cosmetics OTC (over the counter), it is only available as a prescription based ingredient.
As part of a review of OTC products, the FDA published a proposed rule in 2006 to consider the withdraw of the 1982 rule that recommended hydroquinone be GRASE, because of evidence indicating that hydroquinone may act as a carcinogen in rats and mice after oral administration. It is argued that this is not relevant in humans, so the proposed rule recommended additional studies should be conducted to determine if there is a risk to humans. The FDA has yet to make a final ruling, but until then it’s still believed that hydroquinone should remain available as an OTC (over the counter) drug product.
I have considered the facts, studies, reviews and opinions of medical professionals and have concluded that I will continue to use hydroquinone. I would not be concerned if my mom, best friend, husband or children were using hydroquinone. I feel very confidant in the efficacy and safety of hydroquinone. I will continue review and consider any new information and I will modify this post if my opinion changes.
I have read hundreds of pages of studies, reviews, letters and other published literature on the subject of hydroquinone. I am not able to share everything I have learned, but I focused on some of the main points. I have included links to resources that are available on line, I encourage anyone who is concerned about hydroquinone to do thier own homework. I also recommend consulting with your doctor.
If you are using hydroquinone, be sure to use a broad spectrum sunblock and give your skin a resting period from hydroquinone. For example: 3 months on and 3 months off.
There have been reports of counterfeit beauty products and illegally imported skin care products containing mercury. I strongly discourage purchasing skin bleaching creams on-line.
Nomination Profile /Hydroquinone [CAS 123-31-9] Supporting Information for Toxicological Evaluation by the National Toxicology Program /21 May 2009 / Prepared by U.S. Food & Drug Administration Department of Health and Human Services
Hydroquinone: An Evaluation of the Human Risks from its Carcinogenic and Mutagenic Properties / Critical Reviews in Toxicology 2007, Vol. 37, No. 10 , Pages 887-914 / Douglas McGregor /Toxicity Evaluation Consultants, Aberdour, Scotland, United Kingdom / Toxicity Evaluation Consultants, 38 Shore Road, Aberdour, KY30TU, Scotland, UK
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