What Is The Difference Between AHA BHA and PHA?

Which exfoliating acid is right for your skin? How to choose these chemical exfoliants for your skin type and skin problems?

AHA BHA PHA glycolic acid skin exfoliating brightening lactic acid Salicylic acid Chemical Exfoliators For Oily Skin

AHA (Alpha Hydroxy Acid)

AHAs are water-soluble components derived from natural substances such as sugar cane, almonds, milk, grapes, and citrus fruits. They work to peel away the surface of the skin in a targeted manner to remove rough, uneven skin texture, visible signs of sun damage, winkles and enlarged pores.

Glycolic acid is one of the most effective alpha hydroxy acids for the skin due to its small molecular size, which makes it easy for it to penetrate the skin. 

While glycolic acid is the most potent, leading to the most dramatic results, it also has the potential to be the most irritating. That said, if you have sensitive skin or are using new chemical peels, you may experience reactions such as redness, irritation, or stinging. 

For those with these concerns, it may be better to use a gentler alternative that contains lactic acid or mandelic acid

AHAs are recommended for normal to dry, mature, and sun damaged skin because they are powerful humectants that can improve the skin's natural moisturizing factors in the skin.

Glycolic acid

Glycolic acid is the most powerful form of AHA and is derived from sugar cane and is effective at exfoliating the surface of the skin and removing darker, melanin-stained, dead skin cells.

This high-potent acid also reduces the appearance of acne scars, age-related spots, sun damage, and other forms of hyperpigmentation. Ideal for normal, combination, oily, mature skin types.

Lactic acid

Derived from milk and sugarcane. Lactic acid helps freshen up the skin and relieve congestion, but due to its larger molecule size and targeting only the top layer of the skin, it also helps increase the natural moisturizing factors in the skin.

Lactic acid works on all skin types, however is particularly beneficial for sensitive, dry and mature skin.

Mandelic acid

Naturally derived from bitter almonds, Mandelic acid contains antibacterial properties that has been shown to be effective in balancing pigmentatation, treating existing inflammatory acne and preventing future breakouts.

Mandelic acid is a mild version of AHAs due to its larger molecule and it penetrates the skin more slowly, which means it is gentler on your skin. Ideal for dry, sensitive, and acne-prone skin types.

Tartaric acid

Found naturally in many plants and fruits, including wine grapes and tamarinds, Tartaric acid contains antioxidants that protect the skin from from the harmful ravages of free radicals

With its keratolytic and astringent properties, this powerhouse helps to supply the skin with moisture, to improve skin texture and to reduce the visible signs of aging. Great for almost all skin types—sensitive skin, dry, combo, oily—all can benefit.

Citric acid

True to its name, it's present in citrus fruits—oranges, lemons, grapefruit—as well as berries. Citric acid helps adjust pH level and work to lighten uneven pigmentation and smooth out skin texture.

Citric acid is a very powerful antioxidant and  a natural astringent, helping to dry out excess oil, clean pores. Citric acid is generally considered safe for all skin types, however, particularly beneficial for those with oily skin with congested pores.

BHA (Beta Hydroxy Acid)

BHAs are oil-soluble acids that work on the surface of the skin and in deeper parts of the skin to dissolve the keratin plugs, bacteria, and grime that has built up on the skin's surface so that pores can remain clear and free from irritants.

A soothing leave-on BHA exfoliant helps minimizes psoriasis scales and improves the feel of rough, dry and bumpy skin.

BHA is most beneficial for oily, combination, acne-prone skin and those looking to treat superficial acne, like whiteheads, blackheads, breakouts, and small red pimples.

For those with dry, eczema-prone, or sensitive skin, the active ingredient could be too harsh and lead to irritation.

Just note that if you are using strong acids, you are slowly testing your skin to see if your skin can tolerate the new ingredient. Patch tests are very important for testing new chemical peels!

BHA Exfoliators For Acne-Prone Skin Types

Salicylic acid is the most common beta-hydroxy acid and belongs to a class of drugs known as aspirin (salicylates) that have anti-inflammatory and antibacterial properties that help soothe pimples, inflamed skin, and prevent future comedones.

** Please avoid products containing salicylic acid if you are allergic to aspirin. 

Chemical Exfoliators For Oily Skin Types

Salicylic acid is lipophilic, which means it can break down fatty compounds that help to clear out excess oils and reduce sebum levels, thereby preventing pimples, blemishes.

PHA (Poly hydroxy Acid)

PHA is AHA's little sister and has a larger molecular size than AHAs, which makes them slower to penetrate the skin. That means it doesn't exfoliate as hard as glycolic acid and causes less irritation and redness than AHAs, making it suitable for all skin types, especially sensitive skin.

The polyhydroxy acid is not only an exfoliator, it also turns it into a humectant, AKA an ingredient that attracts water to the skin.

They remove dead skin cells and excess buildup on the surface, resulting in a more even skin tone and texture. It also helps reduce fine lines, wrinkles, pigmentation, and acne scars while increasing cell renewal.

Lactobionic acid

Lactobionic acid is an oxidized form of lactose, which is derived from milk and it act as an antioxidant, humectant, and also has anti-aging properties.

The polyhydroxybionic acid (bionics) is safer and better tolerated than its better-known cousin glycolic acid, but effective in reducing the appearance of pigmentation, fine lines, wrinkles and pigmentation, including post-spot marks and sun spots.

This non-irritating acid can be ideal for those with more sensitive skin types who are prone to irritation with other strong exfoliants.


Found in lactose, the sugar in animal milk, or some dairy products, galactose is an energy-providing nutrient that helps healing by stimulating collagen synthesis.

Galactose contains antioxidant properties when ingested and applied topically to the skin, meaning it helps slow aging by protecting your skin from the damaging effects of pollution, UV exposure, and oxidative stress.

This PHA acid is gentle enough for all skin types to use, even those with sensitive skin with frequent rosacea and eczema flare-ups.


Gluconolactone is a crystalline powder extracted from gluconic acid, which is a substance naturally produced by mammals and corn.

Gluconolactone is a humectant, preservative and provides antioxidant and antimicrobial properties that protect the skin by reducing and counteracting free radical production and improving the skin's hydration.

In general, it’s good for all skin types, particularly those with sensitive or mature skin 

Benefits of AHA BHA, and PHA

You can start to experience its remarkable benefits by adding an peeling acids to your skin care regimen.

  • Calm and heal active acne and even prevent future breakouts
  • Softens blackheads, making them easier to extract
  • Diminish the look of wrinkles and fine lines
  • Brightens the skin and improves dullness
  • improves the appearance of hyperpigmentation.
  • Make the skin look and feel firmer and clearer
  • Smooth and hydrate skin
  • Improve uneven skin tone and texture
  • Minimize the appearance of pore size
  • Unclog excess debris and dead skin cells
  • Promote collagen production

How do you know if you need AHA, BHA, or PHA?

First of all, analyze your skin type and current skin issues— if you have dry skin and feel stressed out about skin problems on the surface of the skin such as acne scars, dark spots, sun damage, dullness, shop a product that contains AHA (or PHA if you have sensitive skin).

BHAs are best for oily and acne-prone skin with clogged pores and excess oil, while PHAs can be suitable for all skin types, especially dry, sensitive skin, including those with rosacea and eczema that AHAs and BHAs cannot tolerate.

Still not sure which acid to use? Don't worry, you can use a product that contains both AHAs, BHAs (and PHAs) to work together with your skin problems, from hyper-pigmentation, flaky and rough patches, to cystic acne.

Please note that AHAs increase sensitivity to the sun (compared to BHAs and PHAs) - you should always wear sunscreen after exfoliating to prevent further sun damage.

In addition, since they’re humectants that draw moisture from the inside, which can lead to dehydration of the skin if overused. Do not use it in your daily regimen.

Best Korean AHA BHA PHA Products

SOME BY MI AHA BHA PHA 30 Days Miracle toner serum cream cleanser set acne k beauty world

Now that you know how to do the most common exfoliating acids like a pro. Here are highly rated Korean face care products that help you to reveal a more radiant and brighter complexion. 

Some By Mi AHA BHA PHA 30 Days Miracle Set is one of the best-selling Korean skincare routines for acne-prone, oily, and irritation-prone skin. This Beauty kit has 4-step skin care routine products—cleansing soap, toner, serum, and moisturizer that target  breakouts, pustules and blackheads.

Cosrx is a classic cult favorite skin care brand from Korea that offers many special formulas that cater to all different types of skin problems.

If you have whiteheads on your nose, chin or forehead, here, Cosrx AHA 7 Whitehead Power Liquid is your solution for clear and smooth skin. This gentle facial product gets ride of dead skin cells, sebum, dirt, and pollutants that clogs your pores.

If you have sensitive or easily reactive skin, this mild exfoliating pad with PHA and green tea will work wonders on your skin—Cosrx One Step Green Hero Calming Pad. This calming toner offer soothing relief to hose who suffer from red, irritated and sensitive skin. 

These pre-soaked toning pads can be wiped over the skin to remove any remaining residue and improve the penetration of your next skin treatment such as serum, ampoule or moisturizer.

For oily and acne-prone skin, salicylic acid is a definite go-to ingredient for reducing oil production and combating breakouts, enlarged pores and blackheads. For daily use, you can start a mild facial cleanser—Cosrx Salicylic Acid Daily Gentle Cleanser.

Powered with the natural BHA component, tea tree and willow bark water, this cleansing foam draws out impurities with bubbling micro-foams. For your regular peeling solution, we can check out Cosrx BHA Blackhead Power Liquid and Benton Aloe BHA Skin Toner.

Both products will help clears the skin of dead skin flakes, dirt, grease and contaminants and make the skin soft to the touch and gives it a fresh and bright complexion.

1 comment

Eine deutsche Gebrauchsanweisung wäre schön sehr sinnvoll.

Regina Müller February 03, 2022

Leave a comment

All comments are moderated before being published