hydroquinone vs kojic acid - which one is better at treating dark spots

Want to fade dark spots? You’ve heard that hydroquinone is the gold standard… and the devil. Isn’t there something less irritating?

Kojic Acid may be it. But… wouldn’t that work more slowly?

There’s always a trade off. That’s why you need to get clear on what’s most important to you and which skin-lightener can give it to you.

Here’s the lowdown on Hydroquinone vs Kojic Acid: which one should you choose?

What Is Hydroquinone?

Did you know that this “devil” is found in nature? Hydroquinone naturally occurs in fruits, coffee and even beer. It’s considered the gold standard at treating any kind of discolouration.

Hydroquinone works in two ways: it inhibits the activity of tyrosinase (the enzyme that controls the synthesis of melanin) and increases the cytotoxicity of melanocytes (it kills the cells that produce melanin).

Contrary to popular opinion, it DOESN’T cause cancer (phew!). But, it can irritate skin and, in rare cases, cause ochronosis (gives skin a bluish tint).

Ochronosis is more common in people with dark skin. But it doesn’t seem to be caused by hydroquinone alone (otherwise, everyone who uses it would get it). Using hydroquinone with resorcinol or without sunscreen seem to be the real triggers.

Best picks:

  • Alpha Skincare Dual Action Skin Lightener ($10.99): available at Ulta
  • Paula’s Choice Resist Triple-Action Dark Spot Eraser 7% AHA Lotion ($27.00): available at Paula’s Choice 

Related: Is Hydroquinone A Friend Or For For Skin?


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What Is Kojic Acid?

Kojic acid is made by fungus during the fermentation process of rice in the manufacture of sake, the Japanese rice wine. It inhibits the activity of tyrosinase, the enzyme that’s responsible for the production of melanin.

Skin tends to tolerate kojic acid better. It’s less irritating than hydroquinone, but can still cause irritations and allergies.

Best picks:

Hydroquinone Vs Kojic Acid: How Do They Compare?

A 1996 study tested the efficacy of two similar formulations of glycolic acid/hydroquinone and glycolic acid/kojic acid for melasma.

Patients used the cream with hydroquinone on one side of the face and the creme with kojic acid on the other. The results?

  • 51% of patients responded equally to hydroquinone and kojic acid
  • 28% of patients saw a more dramatic reduction in pigment on the kojic acid side
  • 21% had a more dramatic improvement with the hydroquinone cream

Hydroquinone Vs Kojic Acid: Which One Should You Use?

I can’t give you a clear cut answer. As science pointed out, most people can use both. But others like hydroquinone better than kojic acid or vice versa.

The problem with skin is that it’s a living organ affected by so many different factors, like genetics, environment and life. Science can point you the way, but you still have to experiment to find out what works best for YOU.

But, science is clear on one thing: hydroquinone and kojic acid work best when used together. A 1999 study compared the efficacy of a cream with 10% glycolic acid and 2% hydroquinone on its own and with the addition of 2% kojic acid.

The first cream reduced melasma in 47.5% of the patients. But  when kojic acid was added to the mix, the cream reduced the discolouration in 60% of patients.

The catch? Used together, hydroquinone and kojic acid are more irritating. But the redness and stinging usually disappears by the third week.

The Bottom Line

Both hydroquinone and kojic acid are effective at treating hyperpigmentation. They work even better when used together. I recommend you start with kojic acid because it’s a little gentler and, if that doesn’t work, move onto hydroquinone or a combo of them.