The Skinny on HydroquinoneTruth or Myth, is hydroquinone dangerous in cosmetics? In short we at spaViolet believe it to be safe and effective, with over 60 years approved by the FDA with a concentration of 2% or less. Extensive research has been done, with the FDA through all the research hasn't banned, does not rate it as carcinogenic and metabolizes well in humans, unlike some of the animals that were in studies. In fact the people that handle hydroquinone in their profession have less cancer. (1)
Hydroquinone is known as one of the most effective melanin inhibitors to aid in treatment for hyperpigmentation and skin lightening. Melasma, or unnatural darkening of the skin is created when melanin, the pigment in skin is overproduced, which in some cases can lead to melanoma, a skin cancer. The tyrosinase enzyme, it's activity produces the rate in which melanin is produced in the skin is inhibited with hydroquinone.
Over the counter concentrations of hydroquinone are .5% - 2%, while prescription strength is 4% leading to the most effective and quickest results at the higher concentration. To put this in perspective, a 12% concentration can stop melanin production altogether, as in properties of albinos. Skin lightening creams are very popular, selling more than 15 million annually with the most popularity in the asian culture.
As of now, the FDA has only approved hydroquinone as the only approved skin lightener. This should be reevaluated, as their are many other ingredients that lighten such as licorice extract, vitamin C, niacinamide, magnesium, Alpha Hydroxy Acids (AHA), arbutin, Phloretin, kojic acid, and azelaic acid. Other lighteners take on the term "brighteners" since the FDA doesn't recognize them as lighteners.
Why is Hydroquinone Harmful?Hydroquinone has been known to cause ochronosis which is a bluish black discoloring of the skin, making it look dark and dead looking. This needs to be reevaluated however as over the past 60 years of use, only a small amount of this skin condition has shown up, mostly in South Africa. These products contained illegal ingredients such as mercury which could be the root cause instead of hydroquinone. Currently, hydroquinone is banned in the European Union, Japan and South Africa.
There are reports that hydroquinone is carcinogenic, found in a study when applied injected in large doses in rats. Metabolism of hydroquinone in rats is much different then humans, and with the extensive studies done, it has not been labeled as carcinogenic. No studies have shown that is has any carcinogens when applied topically, in fact hydroquinone is an antioxidant, although a synthetic one.
What to Look for When Buying HydroquinoneHydroquinone degrades fast when exposed to light and air. Make sure the product you have has a small opening and a good closure. The product should be not exposed to light with it's packaging. When using, make sure to apply sunscreen as inhibiting melanin also reduces your protective barrier in your skin to UV rays. Sometimes hydroquinone creams can cause irritation and dermatitis, which is usually from the Vitamin A or tretinoin added to it.
1 - Critical Reviews in Toxicology, May 1999, pages 283–330