Lactic Acid: Benefits and How to Use it For Skin Lightening

Ask anybody about their skincare regimen and chances are, they will mention using lactic acid. As it happens, the acid is among the most beneficial ingredients in most skin lightening products. So, why should you include it in your regimen? Here’s more on lactic acid benefits and how to use it for skin lightening.

Apart from being mild, which makes it great for most skin types, lactic acid is naturally sourced. When used topically, the compound exfoliates and lightens the skin for an even tone. Additionally, it reduces signs of ageing. 

From legends, it seems even the ancient society had discovered the beauty applications of lactic acid. One such tale has it that Cleopatra, described by historians as “a woman of surpassing beauty”, used to bathe in sour donkey milk. 

What is Lactic Acid?

Lactic acid is an organic acid produced by the fermentation of milk. The process involves the conversion of simple carbohydrates into acid by the actions of bacteria. The acid is what gives sour milk and yoghurt a taste that is distinctive from fresh milk. Typically though, industries and other large-scale consumers use a synthetic version of the acid. 

Lactic acid is grouped among alpha hydroxy acids (AHAs). The group includes other acids such as glycolic acid, malic acid, citric acid, and tartaric acid. When infused in cosmetics, AHAs improve the feel and appearance of your skin. Additionally, they act as chemical peels for both superficial and deep exfoliation.  

Lactic Acid Skin Benefits

Lactic acid comes with many properties that can improve your skin, both medically and aesthetically. Here are the different ways in which making the acid part of your routine helps your skin.

  • Improved Moisture Retention 

While most AHAs find their way into skincare products due to their ability to exfoliate the skin, lactic acid comes with an extra benefit; it helps in improving the natural moisture factor of your skin. It acts as a humectant, a substance that draws water from the atmosphere on to your skin. 

This property makes the acid an excellent addition to your lotion, creams, and moisturizers- especially if you suffer from dry skin. Additionally, the acid can sustain the hydration for long, even at low concentrations. 

Lactic acid improves moisture retention by stimulating the biosynthesis of ceramide and glycosaminoglycans. These are essential natural factors in the reduction of transepidermal water loss. As such, lactates treat skin which is extremely dry and tough to slough off.[1]

Also, the acid serves as a keratolytic. It increases the moisture content in the skin by dissolving keratin, a hard substance that holds cells together. Once keratin is softened/dissolved, dead skin falls off much faster, allowing your skin to retain more water. 

  • Chemical Exfoliation

When used on bare unwounded skin, lactic acid sloughs off the outermost skin layers. Consequently, this helps in the removal of the old, damaged and dull epidermal layer. This ‘peeling off’ reveals younger and brighter looking skin. Apart from the soft complexion that comes with shedding dead skin, exfoliation also helps to fade dark spots. 

Joshua Zeichner, M.D on Lactic Acid and Skin Benefits L

Joshua Zeichner, M.D

Director of Cosmetic and 

Clinical Research

Mount Sinai Hospital

At low concentrations, lactic acid acts as a humectant, helping to pull in hydration to the outer skin layer…At higher concentrations, it helps dissolve connections between skin cells on the surface of the skin to enhance exfoliation.[2

Among AHAs, lactic acid is milder, which makes it ideal for delicate and sensitive skin. As a result, it is used safely on dry, oily, and combination skin, without the possibility of peeling your skin raw. 

  • Acne Treatment

If your skin is acne-prone, you might want to try ointments infused with lactic acid. Due to its ability to penetrate and exfoliate deep into the follicular duct, lactic acid could be effective against mild acne. Again, when used topically, it also lowers the skin’s pH. As a result, the growth of acne-causing bacteria gets inhibited.[3

  • Photo-damage Treatment

Photo-aged skin is lax, rough, and unevenly toned. Prolonged exposure to intense sunlight can also obliterate or dilate blood vessels, giving your skin a dull appearance. 

Lactic acid combats premature skin ageing due to sun damage by increasing cell growth factors. The key to this is improved blood circulation by the formation of new vessels. Besides, long term application of lactic acid increases skin thickness, which in turn reduces photodamage severity. 

Lactic Acid for Skin Lightening

Among the many benefits of lactic acid for topical use is its skin lightening properties. It helps your skin fight hyperpigmentation by inhibiting melanin production. 

The mechanism of this effect involves directly inhibiting enzyme tyrosinase’s activities. Specifically, the enzyme acts on melanosomes- subunits in cells that act as sites for skin pigment synthesis. 

Some studies also suggest that lactic acid quickens melanin dispersion, effectively reducing the appearance of dark spots. This mode of action gets merit from the fact that the acid effectively lightens pigmentary lesions such as solar lentigines.4 Its exfoliation effect also plays a significant role in fading dark spots for brighter skin. 

Scientific Studies on Lactic Acid for Skin Lightening

Before we get to how to use lactic acid on your skin, it essential that you scrutinize studies and clinical trials touching on the ingredient’s efficacy. It is no secret that acids can irritate your skin; hence you need more than anecdotal evidence before applying. 

Below are summaries of three extensive studies on the suitability of lactic acid (LA) for skin use.

  • The efficacy of lactic acid in the treatment of melasma was studied at the Rohilkhand Medical College and Hospital, India. 82%LA was used to treat melasma in 20 patients for 12 weeks. The study concluded that “lactic acid peel is well tolerated and safe agent that can be used for the treatment of melasma.”[4
  • A study, published by the British Journal of Dermatology, investigated the increase in cell growth factors. Chiefly, researchers examined changes in the epidermis after topical application of different creams infused with lactic acid. The highest increase growth factors, 2.8-fold, was observed in test products with 3% LA. 

Higher concentrations yielded no significant increase in the parameters under investigation. The study concluded that lactic acid regulated growth factors which contributed to the acid’s treatment of skin disorders.[5

  • A study on the skin lightening properties of lactic acid, published by the Experimental Dermatology, found the treatment efficacious. Under investigation was the inhibitory effect of LA on melanin synthesis. From the results, LA inhibited tyrosinase activity by between 20% and 55%- with high concentrations accounting for the highest inhibition rates.[6]   

How to Use Lactic Acid for Skin Lightening

Depending on skin type and condition, you can use different concentrations of lactic acid. 

Lactic acid for ordinary skincare

For glowing and well-moisturized skin, the best approach is to incorporate the acid in your other products. Dermatologists recommend using a toner, cream or serum infused with a low concentration of lactic acid. These are products with between 1% and 5% lactic acid in their formulation.

benefits of lactic acid

Kenneth Mark, M.D

Clinical Asst. Professor,

New York Universirty

If too high a concentration is used, like any other hydroxy acid, it could be irritating…but typically, it has the least potential for irritation compared to other alpha and beta hydroxy acids.[7]

At this concentration, the acid does not need neutralization and can be used safely without fear of severe side effects. These are leave-on products that can be left on for hours or overnight. The exfoliation and lightening effects of such products are slow and gradual since the acid only reaches the epidermis. 

Lactic acid peels for lighter skin

To exfoliate and lighten skin effectively, you need a high-strength lactic acid serum. For such the concentration ranges from between 30% and 70%. These are peels that dissolve dead skin cells with ease. At this concentration, the acid is strong enough to penetrate deep into the skin and also allow other ingredients to penetrate. 

For improved action, manufacturers mix the acid with hyaluronic acid or other AHAs for a more effective product. While easy to use, these are treatments better performed by trained professionals. If the acid is left on for long or rubbed more than it should, it could leave you with chemical burns and irritations. 

As with all chemical peels, the more potent the acid, the more stronger the exfoliation effect. That said, potent peels might not be what your skin needs. Where possible, use low concentrations unless under a doctor’s supervision.   

Lactic Acid Side Effects

Although lactic acid is a mild acid, it’s still powerful enough to corrode your skin. For starters, exfoliation leaves your skin less protected from environmental damage. 

Sun exposure will dry out your skin and even irritate it more. If left unchecked, sun exposure can make you more susceptible to age spots and scarring.[8]

Other mild effects that might come with lactic acid topical use include rash and itchiness.

In severity, you could suffer from;

  • Chemical burns 
  • Increased skin cancer risk 
  • Blistering
  • Permanent skin colour change- very rare 

How to Use Lactic Acid Safely

Despite the possible side effects, with proper use, lactic acid can be very beneficial to your skin. Here are some pointers:

  • Always slap on some sunscreen with a high SPF rating (30 and above) whenever you use the acid.
  • If you’re a newbie to chemical peels, start with low concentrations and increase the potency, as your skin gets used to the treatment. 
  • Keep away from direct sunlight by staying indoors when it’s too hot or by wearing protective clothing, after application. When possible, use the acid in the evenings only.
  • Carry out a patch test before using the peel- no matter the concentration of the acid.
  • Avoid substance or treatments which can exfoliate or irritate your skin further. When using lactic acid, keep off mechanical exfoliators and hydroquinone and retinoids-based creams. 
  • Do not use the exfoliant if your skin suffers from any of the following: Cuts, wounds, blisters, or active acne.

Lastly, do not overdo lactic acid products. For creams, use on and off, and only when needed. Some dermatologists advise three days of use, followed by three days off. When it comes to deep lactic acid peels, once in a fortnight is enough. 

Lactic Acid Cost and Where to Buy

The acid is available in drugstores and both dispensing and compounding pharmacies. You can also buy it from online marketplaces, preferably from trusted brands. The price depends on the purity of the acid and the presence of other ingredients. 

From Amazon, Pure lactic acid is cheaper compared to one that infused with other skincare ingredients. That said, the concentration does not seem to affect the price much with the same volume of 80% LA going for a low as $10, and 10% LA going for $12. 


Lactic acid is one of the most beneficial skincare acids. Its benefits include moisture retention, exfoliation, acne treatment, treatment of photodamage and skin lightening. For skin lightening, the acid works by inhibiting the synthesis of melanin. Peeling and the other benefits work together to enhance the results further. 

Compared to other AHAs, lactic acid is more tolerated by most skin types. Furthermore, you can use it on its own, in combination with other products or as an ingredient in your home remedies. Luckily, it is readily available for sale OTC in both online and physical stores.


sonia knight

Sonia Knight is the founder of be:skinformed.

Apart from having her own experience with hyperpigmentation, Sonia has gained vast knowledge in the dermatology field. For more info on this, check out our about us page.


Mechanisms of skin hydration, Handbook of Cosmetic Science and Technology, 4th Edition. Pg 83  

These Lactic Acid Lotions Are Perfect for Gentle Exfoliation, Byrdie

The mode of action of ethyl lactate as a treatment for acneBritish Journal of Dermatology   

Effect of 82% Lactic Acid in Treatment of Melasma, International Scholarly Research Notices

Topically applied lactic acid increases spontaneous secretion of vascular endothelial growth factor by human reconstructed epidermis, British Journal of Dermatology

The inhibitory effect of glycolic and lactic acid on melanin synthesis in melanoma cells, Experimental Dermatology

The Best Lactic Acid Skin-Care Products, According to Dermatologists, SHAPE

Everything you need to know about lactic acid peels, Healthline

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