Alpha Hydroxy Acid (AHA) & Beta Hydroxy Acid (BHA): Explained

The uppermost layer of our epidermis or the stratum corneum consists of several layers of keratinized (hardened) cells tightly packed together. As they contain the protein keratin they are tough and have no nucleus.

A cell without a nucleus is a dead cell.

Our skin naturally sheds billions of dead skin cells every day. This is naturally achieved through a process called desquamation. As we age, the natural process of desquamation slows down significantly.

The results of this are dull, dry skin, clogged pores that lead to blemishes and uneven skin tone.

Through exfoliation, we aid the natural shedding process by manually or chemically dissolving the fatty substance that keeps the dead skin cells tightly bind to each other.

Exfoliation makes your skin look younger, promotes redness thus improving your skin colour and improves overall skin health.

Alpha Hydroxy Acid (AHAs) and Beta Hydroxy Acid (BHAs) are a type exfoliation and you can find these two hydroxy acids in a variety of cleansers, toners, scrubs, moisturizers, and even face masks.

Both are highly effective methods of exfoliation and they have a few shared benefits and similar effects, which are:

  • Remove dead skin cells
  • Smooth out rough texture
  • Improve the look of dull and uneven skin tone
  • Decrease the appearance of enlarged pores and fine lines

Besides doing absolute wonders with exfoliating your skin to perfection, there are a few differences in their uses.

Alpha Hydroxy Acid (AHA) & Beta Hydroxy Acid (BHA

How Are AHAs And BHAs Different?

Alpha Hydroxy Acids are natural water-soluble acids found in milk, sugar, and fruits which act by loosening the bonds between the dead skin cells on the skin’s surface and peel them away.

This will allow the new, more evenly pigmented skin cells to regenerate and take their place. After use, your skin will feel smoother to the touch.

Beta Hydroxy Acids, on the other hand, are oil-soluble. While AHAs work on the superficial layer of the skin, BHAs can get deeper into the skin and unclog pores, regulate sebum production and give deeper exfoliation from the inside.

How Do You Know Which Acid To Choose?

AHAs are more often used to even out mild pigmentation like mild sun damage and age spots, chloasma (melasma) and post-acne scarring. Besides that, they can even out uneven skin tone that’s not necessarily a matter of hyperpigmentation and reduce visible fine lines and surface wrinkles.

AHAs are also very effective in minimizing enlarged pores. If you have any of the above issues that you would like to improve, opting for an exfoliant or a mild cleanser that contains AHAs will be a good choice.

BHAs, on the other hand, deliver much deeper exfoliation and are primarily used for acne and more visible sun damage.

They penetrate deeper into the hair follicles and dry out excess sebum and dead skin cells that are clogging your pores and causing acne breakouts. Because of this effect, BHAs are more suitable for oilier skin types.

Alpha Hydroxy Acids

Glycolic acid is the most common type of AHA naturally derived from sugar cane. It contains the smallest particles of AHAs which make it easy to penetrate the upper layers of the skin effectively and break down the bonds between dead skin cells, revealing brighter and fresher skin.

Lactic acid is another common AHA naturally derived from lactose in milk. Like glycolic acid, it is known to have powerful exfoliating and anti-ageing effects with the difference between these two being that lactic acid is less irritating and more moisturizing than glycolic acid. Lactic acid is something I would recommend to more sensitive skins that are seeking a good exfoliating agent. It can also be used in higher concentrations as it is less irritating.

Mandelic acid contains larger molecules compared to both glycolic and lactic acids and it is naturally derived from almond extracts. Due to the large molecules, this particular AHA can be combined with other AHAs to increase the exfoliating effect, but it can do a pretty good job at improving skin texture and pore size when used on its own.

Malic acid is a type of AHA that’s made from apple acids. Malic acid isn’t an effective ingredient on its own, but it is highly beneficial for supporting collagen production and restoring skin vitality when mixed with other acids. It mildly improves hyperpigmentation by decreasing the production of melanin, the brown pigment in the basal layer of our epidermis.

Tartaric acid while not as widely known and researched, is another type of AHA. It is derived from grape extracts and it has antioxidant properties that relieve acne and sun damage.

Citric acid while mainly classified as AHA, it can be a crossover from both AHAs and BHAs, depending on its formulations. It is derived from citrus fruit extracts with the main purpose of neutralizing and balancing the skin’s pH levels.

Beta Hydroxy Acids

Salicylic Acid is a BHA naturally derived from willow tree bark, wintergreen leaves or sweet birch bark. Different concentrations may vary depending on the product at hand with mild percentages of 0.5 up to strongest percentages being 5.

It is a well-known and efficient acne treatment but besides that, it is a powerful “keratolytic agent”.

This means that salicylic acid is a substance that helps stabilize the shedding of skin cells when the body is shedding skin cells “abnormally” fast, which normally happens with conditions like excessive dryness, eczema and keratosis pilaris.

I hope this cleared the fog regarding these two terms that are being thrown around all over Pinterest and Instagram. Both AHAs and BHAs are highly effective exfoliants that can be used separately or combined together to achieve different skin goals.

What are Alpha Hydroxy Acid (AHA) & Beta Hydroxy Acid?

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