Hydroquinone - A topical skin toning/ lightening cream, How safe? (1)

BY: By Professor Robert Kingsford-Adaboh

What is hydroquinone and why is its presence in skin toning creams raising concerns with some health regulating authorities in Ghana, recently, threatening an outright ban of their use? Are there serious health issues associated with its use as a topical skin toning cream? How much of these worries are founded on available scientific facts?


Skin lightening creams made of hydroquinone have been in the news in Ghana and some neighbouring African countries. An example may suffice here:

An online publication, published by  Myjoyonline (http://www.myjoyonline.com/news/2015/) by Naa Sakwaba Akwa, stated, “Currently the FDA allows two per cent of hydroquinone in skin bleaching products but from 2016, all skin lightening products are supposed to be hydroquinone-free, that means zero per cent and this is going to be enforced,” the Head of Communication at the FDA, James Lartey, reported at a public forum in the Volta Regional capital, Ho.  

The purpose of this article is to expose to readers briefly its chemistry, what happens when applied to the skin (topical use), review of current scientific knowledge from scientists in the field (dermatologists, etc.), in the hope of distilling some of the facts from the myths about this product.


Concerns about hydroquinone's safety on the skin have been expressed.These concerns are often over cancer linked to the hydroquinone ingredient. Aside from the cancer scare is exogenous  ochronosis – a skin darkening and disfiguration  condition that is deemed to be associated with the use of hydroquinone in creams. 

In 2006, the FDA (USA) proposed a change to over-the-counter (1.5 per cent - two per cent concentrations) hydroquinone’s previous status as Generally Recognised as Safe and Effective (GRASE), and recommended that the drug be studied further by the National Toxicology Programme (NTP). The FDA’s primary concerns were that hydroquinone may cause cancer, and that it had been linked to ochronosis (skin darkening and disfiguration) in humans.

In the interim, the FDA recommended that hyrdroquinone remain available for over-the-counter use. The FDA’s 2006 actions were based on studies in which hydroquinone was taken orally.  At that time, the FDA stated that hydroquinone could not be ruled out as a potential carcinogen. This conclusion was centred on a two-year study of the oral administration of hydroquinone on rats.  


There have been no reported incidence of cancer from topical application of hydroquinone on humans. Though health concerns are related to oral ingestion of hydroquinone, concerns over topical toxicity and carcinogenesis have been raised but not validated when the product is used correctly as directed. The causal effect of products containing hydroquinone and skin darkening and disfiguration (cutaneous ochronosis) is unclear. It is yet to be established whether cutaneous onchronosis is a direct result of the effect of hydroquinone alone, or other substances present in formulations, or higher concentrations of hydroquinone present in many countries around the world.   However, in a related research on skin complications due to cream use, exogenous ochronosis - a bluish black discolouration of tissues, was observed on the skin of people of Asian, Latin Americans and African descent using creams containing at least  one per cent to two per cent   HQ when used in addition to  several substances. The active ingredients in these cosmetic products are hydroquinone, mercury and corticosteroids. Several additives (concoctions) are used to enhance the bleaching effect.

 The issue of concern that needs to be addressed is that there has been an increase in privately dispensed or physician-based lines of various hydroquinone  formulations and these have not undergone clinical study or FDA evaluation. It is this genre of hydroquinone products that have raised safety and health concerns. 

Fatal side effects associated with hydroquinone are unrelated to its topical use for the treatment of unwanted hyperpigmentation . Rather, cases of human intoxication have been reported after oral ingestion of hydroquinone alone or of the photographic developing agents containing hydroquinone. The major signs of poisoning included dark urine, vomiting, abdominal pain, tremors, convulsions, and coma.  In a controlled oral study on human volunteers, ingestion of 300-500 mg hydroquinone on a daily basis for  three to five  months did not produce any observable pathological changes in the blood and urine. 

The writer is the Head of Department of Chemistry, SPMS,  University of Ghana.  He has over 20 years’ research experience in his area of expertise. 

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