Hydroquinone is considered to be the gold standard for treating hyperpigmentation, a condition characterized by the darkening of one or more areas of the skin, caused by an overproduction of melanin. Not everyone is a fan, though. In the search for an alternative treatment, more and more people are turning to Kojic Acid. But is this really as effective, and safer?
How do Hydroquinone and Kojic Acid work?
Both Hydroquinone and Kojic Acid work by inhibiting tyrosinase, an enzyme needed to make melanin. Hydroquinone also increases the breakdown of melanosomes (melanin pigment granules) in the melanocytes (the cells that produce melanin). Both ingredients are effective at treating brown spots, melasma and freckles.
Do Hydroquinone and Kojic Acid have any side effects?
Yes. Although claims that hydroquinone causes cancer are false, it can still cause irritation and redness in people with sensitive skin, as well as allergies. It can also cause ochronosish (a bluish black discoloration of certain tissues) in people with darker skin tones. Although it is not clear why this happens, it seems to be linked with excessive and unprotected exposure to the sun.
Kojic Acid is often deemed as a safer and gentler alternative for people with sensitive skin who cannot tolerate Hydroquinone, but it has a few sides effects too. It has a high sensitizing potential and can cause allergies. In addition, both ingredients are unstable and can degrade (and lose their efficacy) when exposed to light and air. Therefore, skin-lightening products with these ingredients should be packaged in airtight and opaque tubes.
Which one is best?
Hyroquinone and Kojic Acid work pretty much the same. A 1996 study tested the efficacy of two similar formulations of glycolic acid/hydroquinone and glycolic acid/kojic acid for melasma. The cream with hydroquinone was applied on one side of the face, while the formulation with kojic acid on the other. “Fifty-one percent of the patients responded equally to hydroquinone and kojic acid,” revealed the study. Of the rest, “twenty-eight percent had a more dramatic reduction in pigment on the kojic acid side; whereas 21% had a more dramatic improvement with the hydroquinone formulation.” However, and perhaps surprisingly, “the kojic acid preparation was more irritating.”
Which one should you use?
That depends on which one your skin can better tolerate. Some people respond better to hydroquinone, while others to kojic acid. However, a combination of the two works even better, like a 2013 study, which examined the effects of 1% kojic acid on its own and in a cream with 2% hydroquinone, has shown.
Another study, published in 1999, compared the efficacy of a formulation containing 10% glycolic acid and 2% hydroquinone on its own and with the addition of 2% kojic acid. The results found that the gel with only glycolic acid and hydroquinone reduced melasma in 47.5% of the patients, while the same formula, with the addition of kojic acid, reduced it in 60% of them. However, some side effects, such as redness and stinging, were experienced on both sides of the face, but these settled by the third week.
The Bottom Line
Although both hydroquinone and kojic acid are effective at treating hyperpigmentation, a combination of the two works best. However, both ingredients can cause irritations and allergies in some people so, before starting any treatment, it would be best to consult your doctor.
Do you have hyperpigmentation? If so, do you prefer to treat it with hydroquinone or kojic aid?