Acids in skincare sound scary. Acids can be your friends if used correctly. They can also cause irritation so you do need to know what you’re applying to your face. Used properly they can boost your collagen, reduce pigmentation, even out skin texture, minimise fine lines and wrinkles and up your glow factor.
What is not to love about that!
Everyone wants great skin and doesn’t want to spend a fortune. The Ordinary acid line up means you don’t have to. The Ordinary makes some great acid-based skincare products and is always my first choice when recommending products.
Let’s start with an overview and ask . .
Why Are Acids in Skincare?
The skin on your face is made up of three main layers:
- The subcutaneous
- The dermis and
- The epidermis
The subcutaneous is the deepest layer of skin. It contains fat and connects your skin firmly to muscles underneath.
The dermis contains most of the connective tissues of the skin, as well as nerve endings, sweat glands, and hair follicles.
The epidermis provides weather- and water-proofing layer to protect the body. The epidermis on your face is split into four more layers:
- Stratum Corneum
- Stratum Granulosum
- Stratum Spinosum
- Stratum Basale
STRUCTURE OF HUMAN SKIN
The Stratum Corneum
This is the very top layer of the epidermis. Its name is derived from Latin and means ‘horny layer’. It is out the first line of defence.
The Stratum corneum is the end product of skin production and it forms a vital barrier that stops water loss. It also protects against invading bacteria and damaging radiation from the sun.
The stratum corneum is made up of cells that produce keratin. These cells start life in the stratum basale and are gradually pushed to the surface of the skin as new cells from underneath them. As they move to the surface of the skin they harden and are called corneocytes.
By the time they reach the surface of your skin they are hard and dead. These corneocytes are packed tightly together in a fatty liquid called the lipid matrix.
The lipid matrix is made up of cholesterol and fatty acids. Because it is oil-based it repells water making us waterproof. Its job is to defend.
This means that for skincare products to be effective have to be able to penetrate through this microscopic but though defence shield.
The Stratum Basale
This is the bottom layer of the epidermis. It’s here that cells are born. This layer also contains melanocytes – Cells that contain melanin to protect us from the sun as well as give our skin its tone or colour are also here.
Inbetween the bottom layer and the top layer are the stratum granulosum and the stratum spinosum.
In the stratum spinosum, skin cells start joining together rather than being individual cells.
In the stratum granulosum, skin the cells release their internal fatty acids. This is transformed into the lipid matrix and the cell membrane starts to toughen and form into corneocytes. By the time these cells reach the stratum corneum they are dead, tough and have formed into a protective barrier.
With a large number of cells and structures contained within the skin, as well as it being the first line of defence and a protective barrier it is not surprising that many different things can go wrong.
As we age our skin cells slow down cell production and this leads to dryer skin, dullness and also contributes to the fine line as wrinkles. Fresh plump cells are produced less and take longer to get to the surface.
Acids in Skincare Products
Your skin is your bodies largest organ and its all about defence. This is why acids in skincare are so important.
The tough layer of the stratum corneum needs to be penetrated by skincare products for them to have any effect on your skin.
If a product can’t get through this horny layer then it will do nothing for your skin.
How Acids Penertrate The Stratum Corneum
Any skin care product that you put on your skin to be effective has to first get through the stratum corneum.
There are three ways that a product can do that.
The first way: If at a molecule they are small enough and made from oil they can go via the lipid matrix through the stratum corneum and down to the deeper layers of the epidermis, dermis and in some cases to the subcutaneous.
The second way: The product molecule can dissolve the keratin in the cells and if it is oil-loving it can then get to the deeper levels via the lipid matrix.
The third way: A product can disrupt the ionic bond between skin cells causing them to slough off.
Most acids have the ability to do all of these things.
Hydroxy Acids
Hydroxy Acids are also known as fruit acids are widely used as anti-ageing agents. They are split into three groups the Alpha Hydroxy Acids (AHA’s) Beta Hydroxy acids (BHA’s) and Poly Hydroxy Acids (PHA’s). The hydroxy acids have a lot of science behind there ability to reverse the effects of sun damage, improve wrinkles, skin elasticity, tone and hydration.
Hydroxy Acids are used in the treatment of several skin conditions such as acne, scarring, hyperpigmentation, skin dryness and wrinkles.
They work by dissolving the keratin plates in the stratum corneum and because of this, they allow other products to work more effectively. Beware though, this effect can cause peeling and flaking. The stronger the hydroxy acid the more irritation you’ll get.
How Alpha Hydroxy Acids (AHA’s) Work
Alpha Hydroxy Acid includes glycolic acid (found in sugar cane), lactic acid (found in sour milk and tomato juice), malic acid( found in apples), citric acid (found in citrus fruits) and tartaric acid (found in wine).
The source of AHA’s in skincare is synthetic and made from bacteria and fungus that result from fermentation.
AHA’s are water-soluble, which means they blend into water rather than repel it. This makes AHA’s good for dry skin.
When AHA’s are applied to the skin they breakdown the keratin in the corneocytes cells. This results in the dead cells of the stratum corneum being sloughed off revelling fresher plump cells underneath.
Because AHA’s can penetrate through the stratum corneum they can promote softer skin, smoother skin, fade wrinkles and lightened age spots and reduce acne.
AHA’s can get all the way down to the subcutaneous and help improve the barrier function and restore hydration, and also increase the skins hyaluronic acid. But they need to be at a high concentration to do that – above 10%.
The higher the concentration the more penetration but also the more irritation.
Glycolic Acid is the smallest of the AHA’s is used mainly for the treatment of skin ageing and hyperpigmentation from sun damage.
A negative side effect of AHAs is that because they penetrate fast and deeply they can cause stinging and burning immediately after being applied to the skin.
They need to be above 5% concentration to have any effect on the deeper layers of your skin.
How Beta Hydroxy Acids (BHA’s) Work
Beta Hydroxy Acid (BHA) such as salicylic acid are similar to AHA’s except that they are fat-soluble this means they can be absorbed via the sebaceous glands because they blend with oil, and are not repelled by it. This makes BHA’s great for oily skin.
How Poly Hydroxy Acids (PHA’s ) Work
PHA’s have the same effects on the skin as AHA’s but without the irritation factor.
PHA’s are relatively new to the skincare and cosmetic industry. They are essentially an AHA but contain more (Poly) hydrogen attachments. They are larger than AHA’s which means they don’t penetrate the skin as quickly so are less irritating.
Other Acids In The Ordinary.
Hydroxy acids are not the only players in The Ordinary arsenal. This is because a variety of acids can stimulate skin cell renewal, have the potential to irritate the skin, and can provide long-term cosmetic benefits such as improvements in skin firmness and elasticity and the reduction of lines and wrinkles.
How Azelaic Acid Works
Azelaic Acid is made from yeast and found in whole grain cereals, rye, barley and animal products. It has antibacterial, keratolytic (meaning it breaks down keratin, the primary protein in corneocytes), comedolytic (meaning it breaks down comedones or acne), and its an anti-oxidant.
This acid also kills Propionibacterium acnes (the bacteria responsible for causing inflamed acne) without causing antibiotic resistance. It is fantastic when used to treat inflamed and cystic acne and also rosacea.
How Ferulic Acid Works
Ferulic acid is a potent antioxidant that is found in the cell walls of grains, fruits and vegetables. It helps keep the walls of cells firm and stable. I scavengers free radical damage and it helps prevent. That sounds like the stuff you want in your skincare already.
It also boosts the effectiveness of other ingredients in skincare products.
The cult favourite serum by SkinCeuticals CE Ferulic has boosted the fame of this acid.
RELATED ARTICLE
How Hyaluronic Acid Works
Skin ageing is also associated with loss of skin moisture. The key molecule involved in your skin’s moisture is hyaluronan or hyaluronic acid (HA). It also helps in regenerating healthy skin, reduces inflammation and plays a role in wound healing.
Studies have shown that most of the benefits of HA depend on its molecular size. High molecular weight (or large size) HA has the anti-inflammatory properties.
Low molecular weight HA (or small size) is a potent proinflammatory molecule. Hyaluronic acid is a large molecule and sits on the surface of the skin. You have probably heard that it holds 1000x its own weight in water.
This is true hyaluronic acid draws water to it and then hold it in place forming a barrier n your skin to stop moisture loss.
Our bodies make it naturally so it has a very low irritation rate.
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How Ascorbic Acid (Vitamin C) Works
Humans are one of the few species that require dietary supplementation of ascorbic acid for survival; our bodies do not produce this necessary vitamin. Without ingestion, ascorbic acid would be mostly depleted after 3 weeks. The minimum daily requirement for ascorbic acid is 200 mg.
Unfortunately, UV light exposure depletes up to two-thirds of your skins ascorbic acid stores, and oral intake is not effective at replacing the lost vitamin C.
The good news is that applying vitamin C to your skin can replenish this supply. Vitamin C is notoriously unstable when exposing it to light and air. The only form of ascorbic acid that your skin can use is L-ascorbic acid.
The Ordinary Retinol
Retinol is converted into retinoic acid by your skin. The Ordinary Granactive Retinoid range is also made from an ester of retinoic acid.
Retinol is also an acid-based product. I have written a separate article all but the retinol acids that you can read.
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The Ordinary Acids: AHA BHA PHA
AHA 30% + BHA 2% Peeling Solution
The Ordinary state on their site that this product is: Only for the use of experienced acid users.
I agree with that. This is a potent serum it contains 30% Alpha Hydroxy Acids (Glycolic/Lactic/Tartaric/Citric), 2% Beta Hydroxy Acid (Salicylic Acid), Hyaluronic Acid Crosspolymer, Vitamin B5, Black Carrot and Tasmanian Pepperberry.
This product is designed to peel the top layer of the stratum corneum off.
The addition of Tasmanian Pepperberry and Hyaluronic Acid provides an irritation buffer to the acids.
How To Use:
Clean face and wait for skin to dry.
Do not use on wet skin.
Apply evenly across face and neck using fingertips, avoiding the eye area.
Leave on for no more than 10 minutes. Rinse thoroughly with lukewarm water. Avoid the eye contour and contact with eyes both during application and rinse off.
This low-viscosity solution is intended to be used as a masque. Do not leave on for longer than 10 minutes.
It is not recommended to use more than twice per week.
Contact of the product with the skin must be of limited frequency or duration.
If irritation occurs, cease use and consult a physician.
Use only as directed on unbroken skin.
Keep out of reach of children.
Sunburn Alert: This product contains an alpha hydroxy acid (AHA) and a beta-hydroxy acid (BHA) that may increase your skin’s sensitivity to the sun and particularly the possibility of sunburn. Use a sunscreen, wear protective clothing, and limit sun exposure while using this product and for a week afterwards.
Glycolic Acid 7% Toning Solution
Glycolic Acid is an alpha hydroxy acid that exfoliates the skin. This 7% toning solution offers mild exfoliation for improved skin radiance and visible clarity. The formula also improves the appearance of skin texture with continued use.
How To Use:
Use ideally in the PM. no more frequently than once per day.
After cleaning, saturate a cotton pad with the formula and sweep across face and neck.
Avoid the eye contour and contact with eyes.
Do not rinse off. Continue with additional skin treatments as needed.
If irritation occurs, cease use and consult a physician. Use only as directed on unbroken skin.
Sunburn Alert: This product contains an alpha hydroxy acid (AHA) that may increase your skin’s sensitivity to the sun and particularly the possibility of sunburn. Use a sunscreen, wear protective clothing, and limit sun exposure while using this product and for a week afterwards.
Lactic Acid 10% + HA
Lactic Acid 10% + HA/Lactic Acid 5% + HA
Lactic Acid is an alpha hydroxy acid that exfoliates the skin. This 10% formulation offers mild exfoliation and is supported with a purified Tasmanian Pepperberry known to reduce signs of inflammation and sensitivity that is often associated with exfoliation.
This formula contains a studied Tasmanian Pepperberry derivative to help reduce irritation associated with exfoliation.
How To Use:
Apply once per day, ideally in the PM.
Can be diluted with other treatments to reduce strength until skin develops tolerance.
Avoid contact with eyes.
If irritation occurs, cease use and consult a physician.
Sunburn Alert: This product contains an alpha hydroxy acid (AHA) that may increase your skin’s sensitivity to the sun and particularly the possibility of sunburn. Use a sunscreen, wear protective clothing, and limit sun exposure while using this product and for a week afterwards.
*Lactic Acid has a natural odour that some people find unpleasant, this doesn’t mean the product is rancid.
Salicylic Acid 2% Masque
Salicylic Acid 2% Masque is formulated to target lacklustre tone and textural irregularities.
The structure of salicylic acid targets the removal of dead skin cells on the surface of oily and blemish-prone skin. Charcoal and clays are added to this formula to aid the removal of sebum debris and bacteria that would otherwise clog the pores.
In comparison to Salicylic Acid 2% Solution, Salicylic Acid 2% Masque is a rinse-off formula.
Leave on for no longer than 10 minutes.
How To Use
Use once or twice a week on thoroughly clean, dry skin.
Do not use on wet skin.
Apply evenly acrossyour face using fingertips, avoiding the eye area.
Leave on for no more than 10 minutes.
Rinse thoroughly with lukewarm water.
Do not use on sensitive, peeling or compromised skin.
Avoid the eye contour and contact with eyes both during application and rinse off.
If you develop severe irritation, hives, swelling of eyes and mouth, blistering, or difficulty breathing, rinse off, cease use and consult a physician right away.
Keep out of reach of children.
Sunburn Alert: This product contains a beta-hydroxy acid (BHA) that may increase your skin’s sensitivity to the sun and particularly the possibility of sunburn. Use a sunscreen, wear protective clothing, and limit sun exposure while using this product and for a week afterwards.
Salicylic Acid 2% Solution
Salicylic Acid is a beta hydroxy acid that exfoliates the skin. This 2% treatment solution helps exfoliate the inside walls of pores to fight the appearance of blemishes and for better visible skin clarity with continued use.
On the Deciem website, they note: This product is not medicine. If you are fighting extensive or persistent acne, please consult a physician. Effective medicine exists to fight acne successfully, including retinoic acid and benzoyl peroxide.
How To Use
Use in the AM and PM.
Apply a small dot directly on spots for visible improvement or apply a small amount over the face to maintain visible clarity with continued use.
Avoid the eye contour and contact with eyes.
If you develop severe irritation, hives, swelling of eyes and mouth, blistering, or difficulty breathing, rinse off, cease use and consult a physician right away.
Keep out of reach of children.
Sunburn Alert: This product contains a beta-hydroxy acid (BHA) that may increase your skin’s sensitivity to the sun and particularly the possibility of sunburn. Use a sunscreen, wear protective clothing, and limit sun exposure while using this product and for a week afterwards.
RELATED ARTICLE:
The Ordinary Products For Acne
Other Acids By The Ordinary
Resveratrol and Ferulic Acid
This formula combines very high concentrations of two of the most powerful and important antioxidants in skincare: Resveratrol and Ferulic Acid. Resveratrol is a natural phenol found in several plants and our pure source is 100% derived from Japanese Knotweed. Ferulic Acid is a high-potency phytochemical antioxidant found naturally in walls of plant cells.
Skincare formulations generally incorporate Resveratrol at 1% or less and Ferulic Acid at 0.5% or less. This formula contains each at 3%, an exceptionally high concentration.
Note: Water can impair the stability of any antioxidant. This formula does not contain any water, silicones, oils or alcohol.
How To Use
Apply alone or after water-based serums, before oils or heavier creams.
Alternatively, mix with other treatments to enhance their antioxidant capacity significantly.
This treatment is highly concentrated and can be diluted with most oils per application to reduce strength.
A small amount of Resveratrol 3% and Ferulic Acid 3% and The Ordinary Vitamin C Suspension 23% + HA Spheres 2% or Vitamin C Suspension 30% in Silicone can be diluted in any one of our oils at each application to form an outstanding antioxidant network of Vitamin C, Ferulic Acid and Resveratrol in lipids.
It is recommended to keep this mixture at low strength. If irritation occurs, cease use and consult a physician. Use only as directed on unbroken skin.
Keep out of reach of children.
Do not refrigerate
Vitamin C 100% Powder
Vitamin C is an effective antioxidant that brightens the skin tone and reduces the appearance of signs of ageing.
This formula offers a very fine L-Ascorbic Acid powder that visibly targets the appearance of uneven skin tone, dullness, and signs of ageing and is formulated to be mixed with other treatments (except those containing Niacinamide).
The format of this formula is a very fine L-Ascorbic Acid powder and, as such, provides the most direct exposure of extremely high concentrations of Vitamin C topically. With such format, a very strong tingling but non-irritating sensation is expected during the first 1-2 weeks of use until the skin’s tolerance to such high exposure is elevated.
* If topical Vitamin C is used as part of skincare, it should be applied at alternate times with Niacinamide (ideally Vitamin C in the PM and Niacinamide in the AM). Otherwise, Niacinamide can affect the integrity of pure-form Vitamin C (L-Ascorbic Acid).
The Ordinary’s portfolio of Vitamin C includes the following formulations:
Vitamin C Suspension 30% in Silicone
Vitamin C Suspension 23% + HA Spheres 2%
Ascorbyl Glucoside Solution 12%
Ascorbyl Tetraisopalmitate Solution 20% in Vitamin F
Magnesium Ascorbyl Phosphate 10%
Ascorbic Acid 8% + Alpha Arbutin 2%
Ethylated Ascorbic Acid 15% Solution
100% L-Ascorbic Acid Powder
How To Use
Mix a small amount with other treatments in the palm of your hand and apply to face in the AM or the PM.
Avoid contact with the eyes.
A tingling sensation can be expected after application.
Do not mix with formulations containing Niacinamide.
If irritation occurs, cease use and consult a physician.
Use only as directed on unbroken skin.
Keep out of reach of children.
Hyaluronic Acid
Hyaluronic Acid (HA) can attract up to 1,000 times its weight in water. The molecular size of HA determines its depth of delivery in the skin. This product contains a HA crosspolymer at a combined concentration of 2% for ‘multi-depth’ hydration.
This means it contains small hyaluronic particles and could be potentially irritating to your skin. If you use this product and find your skin becoming irritated it might be due to the small molecule size in the cross polymer. It is for this reason that I don’t use this product.
This system is supported with the addition of Vitamin B5 which also enhances surface hydration.
How To Use
Apply a few drops to face AM and PM before creams.
If irritation occurs, cease use and consult a physician.
Use only as directed on unbroken skin.
Keep out of reach of children.
The Bottom Line on The Ordinary Acids
Acids in skincare are some of the best ingredients for slowing the ageing process and keeping your skin plump and hydrated, preparing damage and protecting your skin barrier function. As always The Ordinary has some great products at wallet-friendly prices.
However, not all of them are ‘best in show’ I am looking at you hyaluronic acid products. But if you are new to acids or want to try something new without giving your wallet a small stroke then you can’t go past The Ordinary Acids.
