Salicylic acid and retinol are two of the most effective skincare ingredients for treating oily, acne-prone skin. However, word on the grapevine is that these two don’t play well when paired. So are the rumors true or false? Can you use salicylic acid and retinol together?
The short answer is yes, you can use them together, as long as you don’t experience any skin irritation – so probably not a great combination if you have sensitive skin.
Salicylic acid is a beta-hydroxy acid that acts as a chemical exfoliant by weakening the bonds between the dead skin cells on the surface of your skin so that they can be shed with more ease.
It’s also anti-inflammatory and oil-soluble which means that it can penetrate your pores in order to unclog them and your oil glands in order to reduce oil production.
Salicylic acid works particularly well in combination with niacinamide to reduce oil production and pore size.
Retinol is a vitamin A derivative that increases the rate of skin cell turnover and renewal, boosts collagen production, reduces sun damage and pigmentation, improves the appearance of wrinkles, and increases skin hydration.
It’s one of the most effective and well-studied anti-aging skincare ingredients.
However, retinol can initially cause your skin to become dry and irritated by damaging your skin’s protective barrier and increasing the amount of water lost from your skin.
Can You Use Salicylic Acid and Retinol Together?
When it comes to layering skincare products and ingredients, the biggest concerns most people have are related to:
- Whether the combination of ingredients will cause skin irritation
- Whether differing pH levels will cause ingredients to ‘cancel each other out’.
Salicylic Acid and Retinol Optimum pH Levels
pH is a measure of how acidic or alkaline a substance is. The pH scale ranges from 1-14 with 7 indicating a neutral pH.
Retinol has to convert to its active form (retinoic acid) in order to exert its effects but it can’t do this until it has penetrated your skin and requires a process called ‘esterification’ to do so. The enzymes that allow this process, and the expression of vitamin A during skin cell turnover, have a ‘low optimum pH of about 5.6’.
It was originally thought that salicylic acid, like glycolic acid and other hydroxy acids, had to have a pH of less than 3.5 in order to be effective.
However, research suggests that there isn’t that much of an increase in the effectiveness of salicylic acid when used at low pHs, just an increase in the amount of irritation and skin barrier damage!
One clinical study actually found that neutralized salicylic acid with a pH of 6.5 was equally as effective as salicylic acid with a pH of 3.12 but caused less skin irritation.
That means that salicylic acid could be used at a similar pH to retinol without reduced effectiveness.
Even if salicylic acid was used at a low pH, your skins natural surface pH is around 5.0 – 6.0, although it can be as low as 4.7 on untreated skin (skin that has not used any products recently), so it often has to adjust to a more alkaline environment anyway.
In addition, while retinol’s optimum pH falls within the range of normal skin pH, the research that it may not function properly at a lower pH may be outdated (the study was published in 1982).
Research also suggests that other acidic ingredients can stabilize retinol and increase its effectiveness.
Therefore, it’s highly unlikely that the pH difference between salicylic acid and retinol are an issue.
But what about irritation potential?
Salicylic Acid and Retinol Mechanism of Action
Both salicylic acid and retinol increase your skin cell turnover but in different ways. Retinol encourages the production of new skin cells and increases the rate that these cells travel to the surface of your skin to be shed.
It’s often thought that retinol exfoliates your skin because it can cause your skin to flake and peel. However, this is a sign of skin barrier damage and dehydration.
Salicylic acid, in contrast, acts at the surface of your skin to break down the bonds that hold your dead skin cells together which enables them to be shed faster.
So both ingredients actually complement each other’s effects.
What Are The Benefits Of Using Salicylic Acid And Retinol Together?
There isn’t a whole lot of research dedicated to this skincare ingredient combination, although the benefits are likely to be similar to the combination of glycolic acid and retinol.
One clinical study found that the use of a salicylic acid cleanser followed by a retinol serum was well tolerated and improved the signs of sun damage (fine lines, wrinkles, pigmentation, etc.).
Retinol has also been successfully used after salicylic acid peels to improve skin texture.
Other research has found that the combination of salicylic acid and retinol can improve acne after 4 weeks of use.
Potential Issues When Combining Salicylic Acid and Retinol
One of the main issues with using salicylic acid and retinol together is that both ingredients, alone, have the potential to cause skin irritation and this may be enhanced when combining the two together. This is particularly a concern for anyone with dry or sensitive skin.
If you experience irritation when using these ingredients together, you may want to reduce the frequency of use of either/both salicylic acid and retinol or use them on alternate days.
It’s also important to only introduce one ingredient at a time unless they are in the same product (as products are often tested for irritation potential).
As well as irritation, both salicylic acid and retinol can cause skin ‘purging’, which is a particular concern for anyone with acne-prone skin.
Skin purging is an initial breakout of spots and pimples that are caused by the use of skincare ingredients and products that increase skin cell turnover. These spots and pimples would have appeared eventually but it can be alarming when they all come to the surface of your skin at once.
Summary – Can You Use Salicylic Acid and Retinol Together
Overall, salicylic acid and retinol can make a great skincare pairing as long as you don’t experience any skin irritation. However, you may want to avoid this combination if you have dry and/or sensitive skin.
You don’t need to use both ingredients every day to reap their benefits, in fact, sometimes less is more!
Finally, despite what you may have heard, pH differences are no issue here!