What is kojic acid and can it really help my dark spots?
Few skincare ingredients give you the green light to dust off hyperpigmentation and dark spots without any nasty side effects. That's where kojic acid differs. Despite having the word ‘acid’ in the name, it is not an exfoliator. Naturally derived from mushrooms, the way kojic acid clarifies your complexion is a lot more nuanced – and gentle – than that.
We asked skin experts and cosmetic doctors to break down this ingredient – from how it works on the melanin in our skin (AKA the substance responsible for your skin colour) to who should try it and how best to incorporate it into your routine.
What is kojic acid?
Kojic acid is a naturally derived by-product of fungi that’s best known for its effects on areas of hyperpigmentation, both sun-induced and post-inflammatory. Specifically, snow mushroom is a rich source. It's also a byproduct of certain fermented foods, including Japanese sake, soy sauce and rice.
How it works
Instead of chemically exfoliating away the outermost layer of mottled skin as an at-home chemical peel would, “kojic acid works by inhibiting the activity of tyrosinase, a melanin-forming enzyme in the skin – thus fading existing areas of hyperpigmentation and preventing future dark spots,” explains aesthetic doctor, Dr Fiona McCarthy.
As a result, adds Dr Ifeoma Ejikeme, skin tone will appear brighter and more even.
What does it do for your skin?
Kojic acid is renowned for evening out skin tone, first and foremost. By suppressing melanin overproduction in the skin, says aesthetic doctor Dr Ana Mansouri, “it effectively targets hyperpigmentation caused by sun damage and acne marks.”
It also acts as an antioxidant.“Kojic acid can neutralise free radicals, which, if left unchecked, can lead to dull skin, premature fine lines, pigmentation and redness,” says Dr Ejikeme. Not to mention, kojic acid has anti-microbial and anti-inflammatory properties. “It’s great for acne sufferers as it features both these qualities, unlike most other acids,” notes aesthetic doctor Dr Sophie Shotter.
Does kojic acid whiten your skin?
Kojic acid does not whiten or ‘bleach’ your skin in the same way as hydroquinone, a controversial prescription-only, ingredient would. It's an important distinction to make as kojic acid evens out your skin tone instead of lightening it.
In clinic settings, however, kojic acid is sometimes combined with hydroquinone to turbo-charge the latter's lightening effects. “The combination of both have a synergistic effect on hyperpigmentation,” says Dr McCarthy, who is a fan of using the two ingredients in tandem.
Is it safe?
Kojic acid is safe to use and “generally well tolerated”, says Dr McCarthy. “I always advise starting with a low concentration (1-4%) and introducing it into your skincare regimen slowly,” she adds.
Much like other actives, including salicylic acid, kojic acid isn't recommended if your skin skews sensitive as it may cause dryness, redness and irritation.
How to incorporate kojic acid into your routine
“Kojic acid can easily be incorporated into your daily skincare routine,” says Dr Sophie Shotter. It’s found in a mix of products – from cleansers to serums – plus, it works well with other skin brightening ingredients like vitamin C and niacinamide. “Depending on the formulation, some preparations can be used up to twice per day in order to utilise its full benefits,” adds Dr Mansuri.
While kojic acid isn't considered particularly harsh, if you are worried about dehydration, Dr Ejikeme has this advice: “If you’re using it in a soap or cleanser, apply products containing ceramides after, in order to restore hydration.”
We also can't stress enough the importance of applying SPF as the final step in your routine. “Otherwise you’re just causing new sun damage while trying to treat the problem that’s already there,” says Dr Shotter.
How long does it take for kojic acid to work?
“The speed at which kojic acid works depends on the severity of hyperpigmentation, as well as the percentage and formulation of the product used,” says Dr Mansuri. “Results are usually seen after four to six weeks of regular use onwards ,but improve with longer-term use.”
It's also worth mentioning that skin concerns can return if you discontinue use. “I recommend kojic acid as part of a long-term maintenance plan for an even skin tone,” Dr Mansuri adds.
Here are the best kojic acid heroes to add to your routine…
SkinCeuticals Discoloration Defense Corrective Serum
SkinCeuticals Discoloration Defense Corrective Serum, £90, LookFantastic
This hardworking serum packs a potent punch with 1.8% tranexamic acid to soothe skin, 5% niacinamide to soften fine lines as well as kojic acid to fade pigmentation. Expect more radiant, healthier-looking skin after use.
PCA Skin Pigment Bar
PCA Skin Pigment Bar, £45, Dermacare Direct
As well as kojic acid, this gentle cleanser contains azelaic acid to even skin tone and niacinamide, a potent antioxidant, that improves barrier function. Use every day to brighten and even skin tone over time.
ZitSticka Hyperfade Microdart Blur Patch
ZitSticka Hyperfade Microdart Blur Patch, £29, Cult Beauty
After a targeted dark spot treatment? Turn your head to these savvy stickers, laced with niacinamide, kojic acid and vitamin c, to brighten skin and break down the dark pigment of stubborn dark spots.
4.5.6 Sevenly Delight Brightening Serum
4.5.6 Sevenly Delight Brightening Serum, £65, 456 Skin
Recommend by Dr Ejikeme, this souped up serum is brimming with melanin inhibitors (including glutathione, alpha arbutin, palmaria palmata extract) to help fight hyperpigmentation, dark spots and acne scars.
