Glycolic acid or salicylic acid: Which is better for you?
Both glycolic acid and salicylic acid are hydroxy acids, but they can be used to tackle different skin issues. They each lightly exfoliate, penetrate the skin and are considered to be active ingredients that should be used with care. And using them properly and regularly can yield fast and long lasting results in skin texture and complexion.
What is glycolic acid?
Glycolic acid is an AHA (or alpha hydroxy acid), is water soluble, and naturally occurs in sugar cane, sugar beets, and pineapples. Alpha hydroxy acids loosen the glue that holds together skin cells and facilitates the exfoliation of your topmost layers of dead skin. Because it helps encourage cell turnover, it can be used regularly to treat and reduce scars, hyperpigmentation, and wrinkles.
Other AHAs include lactic acid (made from milk), mandelic acid (made from almonds), and malic acid (made from apples). However of all the AHAs, glycolic acid has the smallest molecules and so penetrates your skin more deeper than the other AHAs.
Glycolic acid can be found in concentrations from 5 to 30% and the higher the concentration, the more potent the solution of glycolic acid. Using a lower concentration and building up over an extended period of time will help your skin become accustomed to the strengths with less irritation.
Glycolic acid sun sensitivity: All AHAs including glycolic acid increase your skin’s photosensitivity, so you must wear sunscreen if you plan on using using an AHA. These effects can remain for 7 days after using an AHA. If you do not wear a sunscreen, you may end up with even more damage to your skin than before using the AHA.
Glycolic acid benefits include powerful exfoliation for better skin texture, reduction in skin scars, spots, and surface wrinkles and fine lines.
Learn more about AHAs like glycolic acid, the science behind its process, and how to use in our guide to AHAs.
What is salicylic acid?
Salicylic acid is a BHA or beta hydroxy acid which is either naturally derived or biosynthesized from bark of the willow tree. Unlike AHAs which are water soluble, beta hydroxy acids are oil soluble, which means they are able penetrate deeper than your skin surface and deep into your pores. Beta hydroxy acids or BHAs lightly exfoliate your skin’s top layers on their way deeper into your skin where they exfoliate excess oil and dead skin in your pores.
Note: You should not use BHA or salicylic acid if you’re pregnant.
This penetrative action makes BHAs great for treating all types of acne, from surface whiteheads or blackheads to deeper cystic acne. Not only do BHAs, like salicylic acid, penetrate and treat acne, but they also have antimicrobial and anti inflammatory properties that helps treat against future acne.
Salicylic acid can be found in concentrations from 1 to 10% and is best used at low concentrations like 2%. Higher concentrations do not show extra results.
Salicylic acid sun sensitivity
BHAs like salicylic acid do not make your skin more sensitive to the sun and its damage. You can safely use a BHA even if you do not wear sunscreen.
Salicylic acid benefits include light surface exfoliation for improved skin texture and treatment of existing and future whiteheads, blackheads, and acne.
Learn more about BHAs like salicylic acid, the science behind its process, and how to use in our guide to BHAs.
Glycolic acid or salicylic acid – A comparison
Still not sure which one to use? Can you use both?
If you have oily and acne prone skin or you have sensitive skin that cannot tolerate most alpha hydroxy acids, then salicylic acid or beta hydroxy acids are better for you.
But if your primary concern is sun damage or you want increase the hydration in your skin, then glycolic acid or alpha hydroxy acids will help you.
You can also certainly use both. Because they are able to penetrate and act at different levels of your skin, you can use them in combination to deal with skin issues in a wider range. However, we do not recommend that you add both to your skincare routine at the same time. Both salicylic acid and glycolic acid are active ingredients that have immediate results and it is very easy to over exfoliate your skin by getting overzealous and starting both. We recommend adding one, using it for a few weeks, and then adding the second option. This way you’ll be able to determine which acid is showing results and how much results.
You can also alternate using salicylic acid and glycolic acid depending on how your skin is feeling that day or week. If you see an acne spot coming on, spot treat it with salicylic acid. Or perhaps your skin could use some hydration or surface exfoliation – then you can give it some glycolic acid. If you want to alternate products, again please pay careful attention to your skin and make sure that you do not over exfoliate. If your skin feels tight no matter how much moisturizer you use or you experience peeling, stinging, or redness, you may have over exfoliated and you should stop all acid use immediately and work on repairing your moisture barrier.
Next, we’ll take a look at how both or either acid can help treat some of the most common skin issues and the studies that have been done to prove this.
For Acne
Glycolic acid or salicylic acid for acne – which is better?
Salicylic acid, but both can be used together.
Because salicylic acid penetrates from the topmost layers of skin and deeper down into your pores than glycolic acid can, it can better target acne at its source.
Glycolic acid doesn’t do as much for the deeper layers but it is a very potent exfoliator for your topmost layers of skin.
To target a greater range of skin layers, from surface to pore level, a combination of salicylic acid and glycolic acid can be used to treat skin more thoroughly. In one study, a solution of 1% salicylic acid, 10% glycolic acid, and botanical ingredients were used on 25 male and female volunteers with acne and the study showed significant improvements in both inflammatory and non inflammatory acne lesions.
“Tolerability assessments showed that the skin care regimen was very well tolerated by all study volunteers. Acne severity was significantly reduced by two acne grades at six weeks….Standardized photography also demonstrated a progressive reduction in acne lesions over time. In conclusion, results of the present study suggest that the tested skin care regimen offers rapid acne clearance and excellent tolerability that together may help to improve patient adherence as well as treatment outcome.” [source: Bhatia AC, Jimenez F. (2014) J Drugs Dermtol.]
For Sun Damage
Which one is better for sun damage – Glycolic acid or salicylic acid?
Glycolic acid shows good results when use to exfoliate and remove fine lines, wrinkles, and melasma, all issues that can show up with excessive sun exposure and aging.
In one study, a group of 20 Indian patients with melasma were treated with glycolic acid peel. When their results were compared with 20 other patients who did not receive the peel treatment,
“There was an overall decrease in MASI from baseline in 24 weeks of therapy in both the groups (P value < 0.05). The group receiving the glycolic acid peel with topical regimen showed early and greater improvement than the group which was receiving topical regimen only.” [source: Chaudhary S, Dayal S. (2013) J Drugs Dermatol.]
Nearly any of the alpha hydroxy acids (AHAs) can used to reverse effects of sun damage and aging. Just remember, be sure to wear sunscreen during AHA use and for at least 7 days after, otherwise you risk damaging your skin further rather than reversing previous damage.
For Keratosis Pilaris
Which one is better for keratosis pilaris – Glycolic acid or salicylic acid?
Keratosis pilaris or KP is a frustrating skin issue that sets in with a vengeance and refuses to go away. It is a harmless skin problem but can affect your self confidence because it is so visible and difficult to hide using makeup. However, AHAs like glycolic acid can successfully reduce if not entirely remove keratosis pilaris.
Keratosis pilaris results when your body overproduces a protein called keratin which then ends up getting trapped in your follicles and creates hard raised bumps visible on your skin’s surface. It is not contagious and normally not painful.
As you have learned by now, both BHAs like salicylic acid and AHAs like glycolic acid help exfoliate your skin layers. And since KP is an accumulation of keratin in your follicles, both salicylic acid and glycolic acid can help treat keratosis pilaris. Glycolic acid can help exfoliate the top layers of your skin and help open the plugged hair follicles that are causing keratosis pilaris while salicylic acid treats the buildup of keratin in the follicles.
So using a low concentration salicylic acid and a 5-10% glycolic acid in combination can help treat keratosis pilaris. Be sure to add a moisturizer alongside these acids to help speed up your skin repair and reduce dry patches. Also be sure to alternate days with each acid and to start slow by skipping a day until your skin becomes accustomed to acid use otherwise you risk over exfoliating on top of keratosis pilaris.