These days there’s an infinite number of skin acids on the market. From salicylic acid and glycolic acid to the differences between AHAs and BHAs, this is a comprehensive guide to skin acids.
Skin acids can be confusing and the thought of incorporating them into your daily skincare routine can sound scary at first. But skin acids are the ideal skincare ingredient for treating almost every skin concern.
The most common acids are used as humectants (Hyaluronic Acid) and exfoliants (Glycolic Acid and Salicylic Acid). An example of a skincare acid is AHAs, or alpha hydroxy acids, which work on the surface of the skin to dissolve the bonds between dead skin cells so that they can be easily sloughed away.
Another example are BHAs, or beta hydroxy acids, which are also more commonly known as Salicylic Acid. This acid is oil-soluble, meaning it can penetrate beneath the skin’s surface, clearing debris and excess sebum from the pores and reducing oiliness.
If you have anti-aging concerns like hyperpigmentation and fine lines, acne, oily or dry skin or sensitive skin, skin acids should be a part of your daily skincare routine. But there are lots of skin acids available over-the-counter and each of them works differently depending on the specific skin concern you’re trying to address and your skin type. We’re giving you an overview of the most common skin acids, including how to use them and deciding which is right for your skin type. This is /skin regimen/’s comprehensive guide to skin acids.
What are skin acids?
Skin acids are active ingredients used as chemical humectants or exfoliants meant to leave you with a smoother, brighter complexion with regular use. These actives get their name because they actively work to improve the appearance of your skin, whether by stimulating collagen and elastin production, increasing cell turnover, or protecting it actively from skin damage.
An active like a skin acid is a targeted ingredient that has been shown in studies to provide results at the level included in a skin care product. So, if a product contains an ingredient at a low level that has not been shown to be scientifically significant, it is listed as an inactive ingredient, not an active ingredient.
How do skin acids work?
Skin acids work by speeding up cell turnover. Cell turnover is the process in which the skin produces new skin cells from the lowest layer of the epidermis to the top and eventually shed off the skin. This is what keeps dead cells from building up on the skin’ s surface. Skin acids help dissolve the bonds that hold skin cells together, allowing dead skin cells to slough off more rapidly than they would on their own.
What are the side effects of using skin acids?
For as much love as we have for skin acids, like with all good things, it’s possible to overdo it. It’s also important to note that a very small number of over-the-counter skin care products directly state the percentage of active ingredients they contain, and since some acids like alpha hydroxy acids and beta hydroxy acid can be irritating at a high potency, it's a good idea to take a less is more approach, starting with smaller amounts and increasing as you go.
The side effects of going too hard with skin acids include skin irritation, in particular, stinging or burning. Your skin may appear red or flaky, or feel itchy, tight, or painful to the touch. Your skin can also start to feel more dry than when you started. An increase in the number of breakouts is another sign of overdoing it with a skin acid.
What is the best way to apply an acid to the skin?
You should never start by applying your skin acid on the forehead. If any product drips, it can end up burning your eyes.
It’s all very important to read the labels of your products and understand how much tingling or redness is normal and for how long it should last in order to get the best results. You can layer skin acids as long as you know which ones to mix.
You don’t want to use too many drying acids, as your face can become irritated. The safest way to use an acid on your skin is to find the one that works for you, and stick with it. The more you layer, the higher your chances of irritating your skin.
Comprehensive guide to skin acids
are alpha hydroxy acids, a class of chemical compounds that can be either naturally occurring or synthetic. Many are derived from organic sugars, with Glycolic Acid (from sugar) and Lactic Acid (from milk) being the most common. AHAs offer chemical exfoliation as an alternative to manual exfoliation, working by dissolving the bonds between skin cells to allow the removal of dead cells resulting in a smoother skin surface.
or beta hydroxy acids are also chemical exfoliators but work best on oily skin types prone to acne and blackheads. BHAs not only exfoliate the top layer of skin but penetrate blocked pores by making their way into the oil glands, dissolving the paste-like mixture of sebum and dead skin that can lead to spots. The most popular BHA in skincare is Salicylic Acid.
- Glycolic Acid:
- Salicylic Acid:
is an organically derived beta-hydroxy acid used to treat skin concerns like acne, dandruff, psoriasis, dermatitis of the skin, calluses, corns, and warts. Salicylic acid is anti-inflammatory, keratolytic, antifungal and antibacterial. Salicylic acid penetrates deep into the pores to loosen clogged follicles by softening and breaking apart dead skin cells and helping them slough off the skin. Salicylic acid is often used in products like creams, cleansers, toners and liquids.
- Hyaluronic Acid:
- Lactic Acid:
is the most common form of vitamin C in skin care. If you’re dealing with a lackluster skin tone, fine lines, acne scars or a generally dull complexion, l-ascorbic acid is your treatment. It’s a powerful antioxidant that becomes a virtual powerhouse when mixed with other antioxidants for brightening the complexion and reducing the signs of aging. Add a vitamin c booster to your skincare routine if you’re looking for an overall skin pick-me-up.
- Citric Acid:
is an AHA that helps keep other acids within a safe pH range. Citric acid acts as a preservative, helping other skincare ingredients to stay fresher longer. Finally, citric acid helps eliminate impurities from the air, water, and heavy metals on the skin by grabbing onto these impurities so that they can’t enter your skin.
- Azaleic Acid:
is an acid derived from wheat, rye, or barley with antibacterial and anti-inflammatory properties, making it an effective treatment for acne or rosacea. It treats these skin conditions by penetrating the follicles, killing any bacteria and easing the inflammation caused by the infection. Azelaic acid works well on darker skin tones because there's no risk of hypo- or hyper-pigmentation, and it's also been approved for pregnant and nursing women.
also known as Vitamin F, is a fatty acid that is essential in stimulating healthy cell production and turnover. It’s found in skin care oils like rosehip, sunflower, olive and flaxseed. Linoleic acid’s omega-rich structure helps to strengthen the skin's lipid barrier, delivering a healthy-looking complexion.
or Hydroxycinnamic Acid, is a powerful antioxidant that neutralizes free-radical damage from pollution, ultraviolet light, or infrared radiation. It's found in the cell wall of plants like oats, brown rice, peanuts, apples, and oranges. Ferulic acid acts as a shield to protect against the free-radical formation. For instance, when something tries to damage your skin, it creates a certain molecule that in its active state will continue to damage and traumatize the skin around it. Ferulic acid shuts down this process by neutralizing the molecules that are formed that if left alone will continue to damage tissue.
is an AHA made up of large molecules making it ideal for those with sensitive skin. The larger the molecule, the shallower the skin penetration, and that means a lower risk of irritation. Mandelic acid helps improve exfoliation and lower the risk of irritation when combined with Glycolic acid, Lactic acid, or Salicylic acid, but it's unfortunately not enough of a power ingredient to do much on its own.
- Oleic Acid:
is an omega-9 fatty acid that is the most common fatty acid found in nature. Oleic acid penetrates easily and deeply into the skin’s surface, replenishing lost moisture and stopping additional moisture from evaporating. Oleic acid has the ability to restore the natural oil of the skin, without clogging pores and leading to break-outs. It also fights free radical damage caused by environmental stressors and stimulates wound healing, as well as soothes conditions such as eczema, rosacea, and psoriasis.
- Retinol (and all retinoids including retinoic acid, retinyl palmitate and retinol aldehyde):
Skin acids are some of the most versatile and hardworking ingredients in the skin care game. They have the power to zap zits, fade scars and dark spots, erase fine lines and deliver intense hydration almost instantaneously. By whisking away dead cells from your skin’s surface, acids also clear the way for other active ingredients to perform better.
Regardless of which acid you decide to try, it’s important to introduce them into your skin care routine slowly, starting once or twice a week, and increasing the frequency from there. And because acids (excluding humectants like hyaluronic acid) remove the top layer of skin, they can make your skin more sensitive so always slather on an anti-aging sunscreen during the day. It's also a great idea to see a dermatologist who can evaluate your skin and prescribe a specific regimen if you’re still unsure that skin acids are right for you.
By Jaclyn LaBadia, staff contributor