Medically reviewed by Minimalist Health Specialist -  Written by Rithi Choudhury (Journalist)  on 26th Oct 2020

Kojic Acid in Cream, Serum, Soap, or Face Wash - What is best? 

Kojic Acid in Cream

Clear and glowing skin is something everyone desires. But life has not always been fair for those who have not won the genetic lottery for crystal clear skin - Hello dark spots, acne scars, uneven skin tone, and all the other kith and kin of blemishes.

But thankfully, Mother Nature has provided us with wonder ingredients like Kojic Acid to tackle our skin woes. Don't fret at the mention of the word 'acid' because it is very skin-friendly, cosmetic grade acid that can do miracles when it comes to your skin aesthetics.  

What is Kojic Acid? 

Obtained from several fungi species and fermented foods like rice wine and soya sauce, Kojic Acid has climbed the ladder of popularity among skincare ingredients because of its super effectiveness and yet mild nature.

To know more about kojic acid, follow our kojic acid guide.

Benefits of Kojic Acid 

1. Clears the Skin 

Kojic Acid suppresses the formation of tyrosinase, an enzyme needed for melanin formation. Melanin is the pigment that gives skin its corresponding color. Dark skin has more melanin, while lighter skin has less melanin.

When the skin is exposed to direct sunlight, the copper ions present in tyrosinase directs it to become more active and produce excess melanin, which later results in sunspots and hyperpigmentation.

Kojic Acid captures the copper ions and prevents them from activating the tyrosinase, thus directly inhibiting melanin formation. 

2. Brightens the Skin 

Kojic Acid is a chemical exfoliator, which means it acts as a mild bleach and sheds dead skin cells (responsible for causing the skin to look dark and dull) from the top layer of the skin. The resulting surface of the skin is composed of newly revealed, fresh cells that naturally contributes to a radiant and brighter look.

Chemical exfoliators are better and safer than the more mainstream. Often the grainy particles used in facial scrubs cause micro-tears in the skin surface. 

Dr. Harsha Bijlani, Medical Head at The Ageless Clinic, Mumbai. Says 

I prefer chemical exfoliants than beaded exfoliants that tend to damage the skin.

3. Anti Aging 

Kojic Acid has antioxidant properties; therefore, it helps repair and protects the skin from oxidative stress - an excess of free radicals in the body.

Free radicals are unpaired (free) electrons that are constantly trying to steal electrons from the cells and wreaking cellular damage, leading to premature aging.

Some free radicals are naturally produced in the body as a part of the metabolic process, but often free radicals enter the body in large amounts when exposed to UV rays, environmental pollution, cigarette smoke, radiation, etc.

Antioxidants help protect the cells by neutralizing these free radicals by rendering them harmless and reversing the signs of aging. 

4. Controls Acne 

Studies have found Kojic Acid to exhibit antibacterial properties. Thus, people with oily and acne-prone skin will benefit from KA as it may help control acne and clearing existing eruptions.

Although kojic acid is not an acne treatment for persistent acne, you should consider mainstream anti-acne serum 2% benzoyl peroxide

5. Treats Fungal Skin Infection 

Kojic Acid has also exhibited antifungal properties according to studies and may help treat fungal infections like athlete’s foot or ringworm, yeast infection, candidiasis, etc. KA is often added to topical antifungal medications to increase their effectiveness.

Why choose Kojic Acid over other similar benefit-delivering ingredients?

 Kojic Acid is extremely mild than other more potent skin lightening ingredients like Glycolic acid and Hydroquinone.

Doctor Vanita Rattan, MBBS, BSc, and founder of The Hyperpigmentation Clinic, London. Says

I’m actually a fan of Kojic Acid. Kojic Acid is a tyrosinase inhibitor. It's perfect for pigmentation, so it’s definitely worth using.”

Kojic Acid having larger molecular size cannot penetrate as deep as glycolic acid (with smaller molecular structure) that works by dissolving the bonds between the cells and exfoliating the skin.

“You do see immediate improvement when it comes to Glycolic Acid. The problem is that it is the smallest molecule of all the AHAs, and so that means it flies through the skin, can burn the skin, and lead to hot spots,” adds Dr. Rattan. Instead, Kojic Acid works by inhibiting pigment production. Hence people who cannot tolerate more potent options will benefit from KA while addressing skin discolorations. 

Kojic Acid in creams, serums, soap, or face wash? 

 As a mild and potent skin lightener, Kojic Acid is an active ingredient in many skincare and cosmetic formulations, including soaps, face wash/cleansers, creams, and serums. Now comes the question - which formulation should you choose?

The answer lies in your skin type and intensity of hyperpigmentation you have. 

Kojic Acid Serums 

Serums are great options for those with oily/combination and acne-prone skin. Serums generally are lighter weight and often eliminate oil altogether in their formulations. Such serums are water-based and hence does not leave behind a film, unlike creams.

Also, water-based serums are quickly absorbed by skin, thus ensuring more availability of direct active in deeper layers of skin than creams.

Serums like the Minimalist Kojic Acid 2% have taken the formulation game even a level higher by eliminating even water and having an aloe vera juice that provides hydration and soothes the skin and delivers the benefits of Kojic Acid in the form of Kojic Dipalmitate.

Kojic Acid Creams 

Creams formulated with Kojic Acid are suitable options for those with dry skin. They need the oils and other moisturizing ingredients present in the formulation to help with the dryness that KA might cause during the first few applications.

The delivery of active ingredients is less compared to serums, even at higher concentrations.  

Minimalist Expert’s Advice

Even people with dry skin to get maximum benefits of active ingredient Kojic acid can go for serums. To combat dryness, they can add Hyaluronic acid before kojic acid and apply a non-comedogenic moisturizer after Kojic acid serum. 

Kojic Acid Soaps 

Soaps with kojic acid are very popular and easily available but always look for one that declares KA's concentration. Soaps have an advantage because, unlike creams and serums, it can be used all over the body to target hyperpigmentation in places other than the face.

But it is important to remember that soaps are alkaline while our facial skin is acidic with an ideal pH level between 4 to 5.5. Therefore while Kojic Acid soaps can be used for treating mild body hyperpigmentation, it shouldn't be used on the face.

Also, soaps and skin come in contact for a short period, so they are not as effective as leave-on Kojic acid serums or creams.

Kojic Acid Face Wash 

Face washes containing Kojic Acid as an active ingredient can be suitable for ultra-sensitive skin as, unlike creams and serums, it does not sit on the face for long. Face washes are also formulated in such a way that the pH level of the skin is maintained while at the same time thoroughly cleansing it of dirt and grime.

But again, it is less likely to be effective in fading hyperpigmentation and delivering other benefits, unlike creams and serums, because of very less contact with the skin. They can help in getting even skin to some extent.

Side Effects and Safety 

Even though Kojic Acid is better tolerated than most acids, it may cause rare allergies like contact dermatitis (redness, itchiness, flaky skin), burning, or stinging feeling and can be irritating for hypersensitive skin.

However, these side effects are uncommon when using a lower concentration. A concentration of 2% or less is reported to be safe for topical application. Raw Kojic Acid is not only extremely unstable but also can be irritating when applied to the skin.

Most companies in their formulations use the stable alternative Kojic Dipalmitate - a Kojic Acid ester (a mixture of kojic acid and palmitic acid) that is not only safer but also more effective than Kojic Acid. 

“In my lab, we would use Kojic Dipalmitate, which is an ester of Kojic Acid. With that, you can use up to 5% and get the same efficacy again without it being irritating,” adds Dr. Vanita Rattan.

Also, it is vital never to skip the sunscreen - be it rain or shine when using Kojic Acid as decreased melanin level in the skin makes it more susceptible to sun damage.

The Bottom Line

Kojic acid is one of the best anti-aging ingredients, and you can consider including it in your routine. It is safe when used in the right concentration and formulated well.

Kojic acid ester (Kojic Dipalmitate) is equally effective but causes much less irritation than pure Kojic acid. So, a good stable formula includes Kojic acid ester instead of pure Kojic acid.

Kojic acid can be used in any form but choose the one based on your goals and skin tolerance. Serums are most effective, while soaps are least for the face. If you want to use Kojic acid serum and have dehydrated or dry skin, then do not forget to add Hyaluronic acid and a non-comedogenic moisturizer in your routine.