Acids In Skincare

April 07, 2019

Acids In Skincare

While some of us may be well versed on the Hydroxy Acid Alphabet to the uninitiated the words skin and acid may sound like an unimaginable pairing rather than a route to a more youthful, glowing complexion but with judicious use they can safely deliver the latter.

Firstly to understand how this process is achieved we need to talk about cellular turnover, which is a measure of how quickly our skin produces new cells. Every minute we lose an average of 30-40,000 skin cells. In fact 90% of household dust is in fact made up of dead skin cells. In infancy and youth cellular turnover along with with collagen and elastin production is at it’s highest, the skin is in a constant state of regeneration which naturally keeps it looking firm, plump and enviably line free.

As we age or Ahem, as I like to say mature ! elastin and collagen the main structural protein in our skin begins to slow it’s production and the rate of skin cell turnover decreases. This is a major factor in how our skin looks and feels. Additional factors can also accelerate this process, aside from our genetics playing a part it is our lifestyle choices and how we look after ourselves that further deplete or enhance our existing collagen stores. Smoking, lack of sun safety and a diet low in vitamin C and high in toxic sugar being the main culprits.

What Effect Does Reduced Cellular Turnover Have On The Skin?

As skin cell renewal slows, it leaves all those dead skin cells hanging around like unwelcome lodgers on the skin’s surface. The build up gives the skin a dull, dry grey appearance. Pores can become blocked, lines are exaggerated and it’s texture is no longer smooth. 

The good news however is there is a lot you can do to preserve and boost collagen production and skin cell turnover.

This is where the "Hydroxy Acids" come in to play ! 

So What Are They And How Do They Work?

Hydroxy Acids are our Skincare Super Heroes and multi-taskers in a bottle!

They are excellent chemical liquid exfoliators. Unlike traditional scrubs that scratch and damage the skins surface, they work by dissolving and loosening the sticky glue-like bonds that hold our dead skin cells together to reveal healthier younger cells beneath.

They can also function beneath the surface of the skin in the deeper dermal layers to deliver many more additional benefits, such as clearing blocked pores, lightening existing pigmentation and preventing new pigment forming by actively suppressing Melanin production.

They can also help to increase skin firmness and suppleness by stimulating the production of collagen and elastin. Hydration levels are also boosted with the production of Hyaluronic Acid which has an exceptional ability to hold 10,000 times it’s weight in water. It is the ultimate humectant for the skin, quenching dry or dehydrated skins.

Before incorporating any acid into your skincare routine it is important to identify your unique skin concerns and to introduce them slowly in order to achieve optimal results. Acids may be found in multiple formulations such as cleansers, lotions and serums and toners. It is important to only use one acid containing product in any one routine. Depending on the strength use once or twice a week initially to gauge how your skin will react before increasing the frequency. Overuse or inappropriate use can have a disruptive effect on the skins protective acid mantle, causing dryness, redness and irritation, not a good look ! 

Remember "The Road To Glow Is To Take It Slow"

How To Decide Which Type Of Acid To Use?

Hydroxy Acid’s fall into two main categories and also a lesser known third sub-category

  • Alpha Hydroxy Acids (AHA’s)
  • Beta Hydroxy Acids (BHA’s)
  • Poly Hydroxy Acids (PHA’s)

All Acids can be synthetically created or derived from various natural food sources.

*Note - AHA’s increase the skins sensitivity to the sun. Always stay sun safe and WEAR A BROAD SPECTRUM SUNSCREEN DAILY, otherwise the object of the exercise is defeated if you are to expose new skin cells to more sun damage and pigmentation, not to mention your increased risk to skin cancer.

The Alpha Hydroxy Acid’s include:

  • Glycolic
  • Lactic
  • Mandelic
  • Citric
  • Malic
  • Tartaric

Which Acid Is Right For You?

The AHA’s most frequently used in skincare are discussed below.

Glycolic Acid 

Of all the AHA’s glycolic acid has the smallest molecular size and so can penetrate the skin the quickest. It is naturally derived from sugar cane.

What Does It Do?

  • It imparts radiance and clarity to the skin by exfoliating superficial dead and pigmented skin cells.
  • It increases hydration levels in the skin by stimulating the production of hyaluronic acid and helps to prevent trans epidermal water loss.
  • It improves skin firmness and reduces the appearance of deep wrinkles, owing to its small molecular size and it’s ability to penetrate the skin quickly, it is the most efficient acid for stimulating collagen production.

It Will Suit Those With

  • Normal to dry skin
  • Fine lines / deep wrinkles
  • Hyperpigmentation
  • Photo or sun damaged skin
  • Age spots
  • Acne Scarring
  • Darker skin tones with care!

Who should avoid it?

  • Sensitive skin, it can be more irritating as it penetrates the skin so quickly
  •  In Darker skin tones, overuse may cause the skin to react causing post inflammatory hyperpigmentation and may create a boomerang effect.
  • Oily / spot prone, Salicylic acid being oil soluble is a better choice.

Lactic Acid

It is a naturally occurring water soluble acid derived from sour milk, it is gentler and causes less irritation than glycolic acid because of it’s larger molecular size. It may however still cause irritation for those with sensitive skin.

What Does It Do?

  • It exfoliates the upper layer of dead skin cells improving the appearance of fine lines. It can increase hydration levels in the skin and improve its barrier function.
  • It can help to lighten sun spots and pigmented areas of the skin by increasing cellular turnover and inhibiting the production of melanin.

It Will Suit Those With?

  • Normal
  • Dry dull skin
  • Mature Skin
  • Pigmentation marks
  • Acne scarring

Mandelic Acid

It is a fat soluble AHA derived from bitter almonds and cherries.

What Does It Do?

  • It has a molecular size larger again than glycolic and lactic acids making it a gentle exfoliator and a suitable choice for sensitive or reactive skin types.
  • As it is oil based it can work both as a superficial exfoliator and at lower levels to deep clean the pores. It’s antimicrobial and anti inflammatory properties make it an excellent choice for acne or spot prone skin. It is also suitable those with darker skin because it does not trigger any post inflammatory responses that may cause pigmentation.
  • Overall it is a great multi- tasker

It Will Suit Those With

  • Normal to dry skin
  • Sensitive or Rosacea prone
  • Acne or spot prone
  • Darker skin tones 

Who Should Avoid It?

Mandelic acid can be used by all skin types even those with sensitive skins but always carry out a patch test and increase frequency of use gradually. 

Citric Acid

It is a naturally occurring acid derived from Citrus fruits

What Does It Do?

Citric Acid is an excellent antioxidant, protecting the skin from those nasty free radicals triggered by sun exposure and pollutants.

A worthy armoury of defense in the fight against damage to the skins cellular structure and accelerated aging.

It is used widely in many skincare formulations due to its natural preservative properties and it’s ability to adjust the pH of products and to add fragrance.

At higher concentrations it provides gentle exfoliation and in some cases it has been shown to increase dermal thickness. It’s anti-microbial properties make it beneficial for acne prone skin.

It Will Suit Those With

  • Acne prone skin
  • Normal / Dry skin

Who Should Avoid It?

Citric acid is generally well tolerated but it may cause some irritation to those with sensitive or reactive skin.

The Beta Hydroxy Acids (BHA’s)

Of this group Salicylic Acid is the most widely known BHA in skincare. It is naturally derived from the bark of the willow tree, the tree is also the source of Salicin, one of the earliest known plant derived therapeutic compounds used to provide relief from pain, fever and inflammation. A less irritating derivative of Salicin - Acetyl Salicylic Acid was synthesized and patented by the Bayer Pharmaceutical company in Germany in 1899 and there began the production of Aspirin, one of the most widely used medications globally.

As always your daily routine should include the application of a broad spectrum sunscreen, but extra diligence is imperative when using any exfoliating acid product as it thins the surface layer of the skin.

Salicylic Acid

What Does It Do?

As well as acting as an effective surface exfoliator, because of it’s oil-soluble or lipophilic properties it works to deep clean and unclog pores for those with congested skin. It’s anti-inflammatory, calming properties will benefit this group and also those suffering from inflammatory or scaly skin conditions such as seborrheic dermatitis on the face, dandruff on the scalp and psoriasis. Wash off formulas that do not need a prolonged contact time with the skin are very effective and less likely to cause irritation compared to serums or formulae intended to be left on the skin.

Salicylic Acid in a lotion formulation is also beneficial in the treatment of Keratosis Pilaris which is caused by the excess build up of the protein (Keratin) in the skin’s hair follicles, trapping dead cells and the hair forcing it to grow inwards, this produces the typical red bumpy presentation commonly referred to as "chicken skin". It is most often observed on the upper arms, thighs and buttocks.

As Salicylic acid also acts as a keratolytic agent it breaks down this excess Keratin giving the skin a smoother appearance.

It Will Suit Those With

  • Oily skin
  • Acne / spot prone skin
  • Clogged Pores
  • Those with red scaly skin and scalp conditions
  • Those with Keratosis Pilaris
  • Mature skin to impart a brighter glow.

Who Should Avoid It?

  • Not suitable for those with rosacea and sensitive skin, dry skin or eczema
  • Not recommended for those who are pregnant or breastfeeding or for those allergic to Aspirin.

The Poly Hydroxy Acid’s (PHA’s) - The Multitasker Of All Acids.

The Poly Hydroxy Acid’s or PHA’s were first discovered in 1974 by Doctor Eugen Van Scott and Doctor Ruey Yu, founders of the Neostrata Company. They are all naturally derived and are usually formulated in combination they include:

  • Gluconolactone: derived from corn 
  • Lactobionic Acid: derived from milk sugars 
  • Galactose: derived from sugars
  • Phytic Acid: derived from the hulls of seeds and rice 

PHA’s are the cousins or second generation of Alpha Hydroxy Acid’s. They have a similar action to the AHA’s, in that they are very effective chemical exfoliators. As their molecular size is larger again than their acidic counterparts they are very gentle on the skin which is great news for those with sensitive rosacea prone skin, they can also enjoy the additional radiance boosting benefits that these hard working acids have to offer. They are not known to increase the skin’s sensitivity to sunlight.

What Are The Benefits of PHA’s?

  • As effective surface exfoliators they bid farewell to dull dry or photo aged skin to greet a fresher more youthful complexion. This also enables other skin actives to get to work more effectively, an added bonus for your pocket too!
  • Gluconolactone is a powerful antioxidant comparable to that of Citric Acid, scavenging the free radicals that damage the skins foundations, stimulating growth and repair in the epidermis and protecting it from Ultra Violet damage.
  • Gluconolactone displays excellent Humectant properties superior to that of the well known AHA’s Glycolic and Lactic Acid. Healthier hydration levels will plump fine lines and dry skin also improving its barrier function.
  • Gluconolactone and Lactobionic acid, through a dual approach work to simultaneously rebuild the support structures of the skin, while actively preventing it’s degradation. They achieve this by increasing levels of Glycosaminoglycans (GAG’s) a group of protein chains, their role is to balance and maintain the structural support system of the skin by preventing the breakdown of collagen thereby increasing skin firmness. They also promote the retention of water in collagen and elastin fibers to increase hydration levels in the skin, Hyaluronic Acid the super hydrator is one such example. 
  • Gluconolactone also causes a reduction in the levels of Matrix Metalloproteinase (MMP’s) a group of enzymes responsible for the breakdown of the supportive proteins in our skin. It inhibits the enzyme elastase which damages elastin in the skin causing sagging and loss of tone.
  • Phytic Acid is useful as a brightening agent for the skin. It helps to reduce pigmentation by inhibiting Tyrosinase an enzyme responsible for the production of melanin.

Azelaic Acid

Another extremely beneficial acid to add to your armoury is Azelaic Acid. It can deliver multiple skin benefits but is equally gentle with it’s ability to calm and soothe. Azelaic Acid is found naturally in wheat, barley and rye. It is a natural substance produced by a yeast that lives on our skin called Malassezia furfur. It is suitable for all skin types and for use during pregnancy.

What Are The Benefits Of Azelaic Acid?

  • Similar to all the acids it is a gentle chemical exfoliator, aiding the removal of dead skin cells to reveal a fresher complexion and reducing the appearance of fine lines and wrinkles.
  • It has an anti-inflammatory effect on the skin reducing redness and swelling in acne prone skin, and soothing and calming those suffering from rosacea.
  • It’s anti-microbial properties reduce the bacteria in the skin responsible for acne (Cutibacterium acnes).
  • It can even reduce pigmentation by depressing melanin production and so improving skin tone.