A to Z of Acids

What are Acids? Acids are a group of ingredients that are commonly used in skin care formulations, one of the most popular is Glycolic Acid followed by Retinol - Vitamin A (we will be covering Vitamin A in a seperate blog post). Acids help to dissolve the chemical bonds between skin cells on the surface of your skin, breaking them apart allowing the skin cells to come away known as 'Chemical Exfoliation'. In essence they help remove the dead part of your skin in the outer most layer called the Stratum Corneum thus, revealing the more light reflective cells underneath. Like all things in life balance is key, too much exfoliation whether chemical (acids) or physical (manual exfoliation) is going to strip away your skins protective barrier resulting in an impaired barrier function; which can lead to skin sensitivities - and yes outbreaks too. (read about causes of sensitive skin here)

How can acids help

  • Breakouts - Removing built up dead skin cells which clog pores
  • Dull Skin - Removing built up dead skin cells which dulls the skins appearance 
  • Dry skin - Humecant capability = moisturising agent
  • Pollution - Lessens the skins ability to rejuvenate and slows down the rate of cell turnover. Acids speed up skin cell turnover via chemical exfoliation.
  • Collagen - Help to stimulate collagen and glycosaminoglycans* (GAG's) production and protect against collagen degradation *GAG's are polysaccharides, also called amino sugars (a sugar linked with a protein). Together with water, they create a fluid that fills the space between the collagen and elastin fibers in the dermis, giving it turgidity.
  • Skin Barrier Function - Can help support and restore the skins 'Acid Mantle' protecting our skin from water loss // microbes // chemical pigment shield to prevent UV damage.

The Acid Families 

We can split acids into three main categories:

  1. Alpha Hydroxyl Acids AHA's - Water soluble are the best hydroxy acid for the signs of aging as they focus their effects on the skin’s surface. In addition to exfoliation, AHAs stimulate collagen to increase firmness and elasticity, increase glycosaminoglycans for thicker, more supple skin, and regulate keratinization to maintain skin hydration and thickness. 
  2. Beta Hydroxyl Acids BHA's - Oil soluble acts as an exfoliant to increase shedding of dead skin cells. BHA is oil soluble so that it can penetrate oily pores and exfoliate the pore itself, making it extremely useful for helping to manage conditions that involve blocked or clogged pores.
  3. Poly-Hydroxy Acids - Are a type of AHA that penetrate in a slower and more gradual manner without irritation or stinging, and are a great option for natural chemical exfoliation of sensitive or dry skin. PHA's support the matrix around collagen, help restore skin barrier function, protect against collagen degradation, and lock in moisture.

A TO Z OF ACIDS a to z of cosmetics acids

ASORBIC ACID Also known as Vitamin C - Anti-inflammatory // Antioxidant - Helps
to reduce free radicals which in turn degrade collagen and elastin // reduces fine lines // acting as a brightening agent that fades dark spots
Category: Carboxylic acid - Are most effective in providing antioxidant protection and slowing the signs of ageing, along with improving moisture-retention.
Best for: Pigmentation prone skin

ACETIC ACID - Apple Cider Vinegar, which pairs acetic and malic acid.
Category: Carboxylic acid - Are most effective in providing antioxidant protection and slowing the signs of ageing, along with improving moisture-retention.
Best for: Tone the skin (NOTE Too acetic to use without dilution)

AZELAIC ACID -  Antioxidant with skin soothing effects primarily used to treat rosacea // skin brightening // Excellent anti-inflammatory // Antibacterial helps to prevent clogged pores by eliminating bacteria to reduce white and black heads // Inhibits the skins excess production of melanin (pigmentation) // Natural exfoliant.
Category: Dicarboxylic Acid - An organic compound derived from grains
Best for: Exfoliate without irritation // Redness prone skin // Acne treatment 

CITRIC ACID  - Is an alpha hydroxy acid that sloughs off dead skin at the surface, an antioxidant best for those showing early signs of aging or with sun damage. Commonly used in cosmetics as a pH adjuster.
Category: (AHA)
Best for: Early signs of aging // Sun damage

GLUCONOLACTONE - one of the most prevalent PHAs is praised for being effective without the redness, peeling, and sensitivity that comes with heavier-duty acids. But it also doesn't penetrate as deep as they do.
Best for: Non-irritating exfoliation. 

GLYCOLIC ACID - A popular and well known alpha hydroxy acid one of the most effective acids it's small molecule size give it the ability to penetrate deeply to stimulate fibroblast cells which in turn support collagen production.
Category: (AHA)
Best for: Reducing wrinkles

HYALURONIC ACID - Is humectant, meaning it helps skin attract and retain moisture // helps to strengthen the barrier of the skin so that its softer, smoother and appears more plump.
Best for:

LACTIC ACID  - A good chemical exfoliant also a good humectant (that the other exfoliating acids lack) which is helpful for dry and dull skin. It is a popular alternative to glycolic because it works in the same way, but it's milder, and works more to moisturise skin while it exfoliates. Often derived from sour milk // yogurt. Lactic acid is a glycosaminoglycan (similar to Hyaluronic Acid) and as such is made of long sugar-like chains. These provide the skin with moisture making this Lactic Acid moisturising and deep cleansing. This is just one of the reasons why Lactic is better tolerated and more flexible than glycollic acid.
Category: (AHA)
Best for: Gentle exfoliation // Moisturising // Good for sensitive skin // Deep Cleaning.

MALIC ACID - Alpha hydroxy acid derived from applesAn AHA that lacks the exfoliating power of glycolic and lactic acids, but is more popular than citric acid. Most often formulated with malic acid and found in 'brightening exfoliants'. 
Category: (AHA)
Best for: Skin tone

MANDELIC ACID - Has the largest molecule of all the AHAs which allows it to penetrate skin slower and gentler than the others, making it perfect for those with sensitive skin. It's antibacterial (great for acne!) and exfoliating without brightening like other AHAs, making it a favorite of those of us with deeper skin tones. Comes from bitter almonds. 
Category: (AHA)
Best for: Gentle exfoliation // good for sensitive skin

    SALICYLIC ACID - Is a Beta hydroxy acid it will still exfoliate but penetrate deeper than AHAs because they're oil-soluble to the root of your pores rather than the surface level.
    Category: (BHA)
    Best for: For treating oily and acneic skin // an extremely effective heavy-duty exfoliant for everyone unless you have skin sensitivity or impaired barrier.

    TARTARIC ACID - Alpha hydroxy acid found in wine, has antioxidant properties and is popular as a pH balancer. 
    Category: (AHA)
    Best for: Antioxidant 


    If pregnant or have an acute inflammatory skin condition acids are best avoided or further advice to be sought from a skin specialist // Dermatologist, we all have different skin along with contributing factors to be considered when designing your best skin care routine.

    Acids can be combined but you must be very careful to avoid one active ingredient inactivating another ingredient or creating the potential for skin to be irritated. With sensitive skin try splitting the use of acids to minimise the potential for skin reactions.  

    Until next time..
    be human | be kind | be you






    Thank you thank you thank you! at last I now know what chemical exfoliation means, who knew there were so many different acids used in skin care but now I GET IT!
    Brilliant post as always
    ps can’t wait for the retinol post

    Tess October 21, 2017

    Fantastic blog really enjoy how you explain stuff, ingredients and how things work.

    Jordan October 21, 2017

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