Do the TikTok-famous kojic acid soap bars really help reduce hyperpigmentation?

Sep 24 , 2025

Kojic acid soap, such as Kitsch’s, is popular on social media – but does it really work? Photo: Handout

Beauty influencers sing the orange bars’ praises, but do they really deliver on promises to fade dark spots, even out skin tone and brighten complexions?

Scroll through the beauty section of TikTok and it’s almost impossible to miss them: kojic acid soaps are everywhere. Bright orange and instantly recognisable, these bars promise to fade dark spots, even out skin tone and brighten complexions – all for the price of lunch. Under hashtags like #kojicacidsoap and #kojicacid, content creators post sped-up bathroom montages, dramatic before-and-afters, and timing hacks for how long to leave it on before rinsing. Among people with melanin-rich skin, where hyperpigmentation is a shared concern, they’ve become something of a cult product.

The only question is: are they a true skincare breakthrough, or just very photogenic bars of soap?

What’s the science behind kojic acid?

Brands like Atomic Aura offer kojic acid soap bars. Photo: Handout

“Kojic acid is a natural brightener derived from mushrooms and fermented foods like sake and soy,” says Amy Wall, a licensed esthetician. “It works by blocking tyrosinase, the enzyme your skin uses to make melanin. It’s not breaking down pigment that’s already there; it’s slowing the production of new pigment, so your skin tone can even out over time.”

As your skin naturally turns over, older, darker cells rise to the surface and shed, revealing fresher cells with less pigment, making kojic acid a slow and steady player. “Consistent use is key because you’re working with the skin’s cycle, [it’s] not an instant bleaching effect,” Wall adds.

What are the benefits of kojic acid?

Kitsch offers a face and body wash formulated with kojic acid. Photo: Handout

Its star power comes from tackling uneven skin tone and stubborn dark spots, whether from acne, sun damage or melasma. It’s also a bit of a multitasker: along with pigment control, kojic acid brings antioxidant and antimicrobial perks to the party, helping support overall skin health.

And when formulators really want to impress, they double down on the brightening team. “When paired with other pigment-balancing ingredients like bearberry, arbutin, vitamin C or niacinamide, it creates a synergistic effect that targets uneven tone from multiple pathways while supporting skin health,” says Wall.

The soap vs leave-on dilemma

There are pros and cons to using kojic acid products, such as Koji’s White Pure Kojic Acid Skin Brightening Soap. Photo: Handout

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