Hydroquinone has been used for decades as a skin lightening agent. As a result of concerns about mid-term effects like leukomelanoderma en confetti and exogenous ochronosis, its use in cosmetics has been banned since January 2001.

Objective
Until recently no attention was paid to potential long-term side-effects, despite the fact that there are indications that these may exist. It was decided that a clearer picture of these potential long term effects was needed.

Methods
A literature search was conducted with an emphasis on the biochemistry and toxicology of hydroquinone, benzene and related molecules.

Results
It appeared that since 1996 an enormous amount of articles have been published on the carcinogenicity of hydroquinone, benzene and related molecules.

The literature search on hydroquinone as a skin lightening agent suggests that possible long-term effects like carcinogenesis may be expected.

Conclusion
The risks of long-term effects (cancer) of topically applied hydroquinone may no longer be ignored. Based on recent evidence of the potential risks, which are higher than has been assumed up until now, we plead that the use of hydroquinone as a skin lightening agent will be stopped completely.