Ingredients in today’s skin care products are alpha hydroxy acids, beta hydroxy acids, linoleic acid… Acids are everywhere in skin care these days it seems.
On the one hand, they can be rewarding, giving your a smooth and glowing complexion. But at the same time, they can be intimidating, especially since they’re often associated with chemical burns.
So I often get the question (or a variation): Can you layer actives? Can you mix acids? Can you use more than one acid in your routine?
Well, the answer is kinda. Or it’s complicated. Perhaps the best way is to know is to understand what skin type you have and what concerns you want to address. From there you know which acids work best for what skin type and concern depending on molecular size.
AHA, BHA, PHA
What usually comes to mind when skin care acid is mentioned is a chemical exfoliator. It’s a skin care product formulated with an acronym such as AHA, BHA, or PHA (more about these abbreviations later).
These are meant to improve skin texture. They work by loosening grime (think dead skin cells, sebum, and so on) on your skin’s surface so that it can be whisked off. Alpha hydroxy acids (AHAs) and beta hydroxy acids (BHAs) are well-known types. Then there’s also PHA.
Their main difference is the chemical structure. This is what determines how deep into the skin each group of acid can absorb into the skin.
AHAs stands for alpha hydroxy acids. This group of acids is water-soluble and generally spoken only break down the outer layers of dead skin cells. After all, our skin is made of mostly water. AHAs are naturally found in many things such as fruits, milk, or sugar cane. They can also be man-made and are probably the most commonly used type of acids. As a rule of thumb, AHAs are when you want to address dull, dry, or ageing skin.
Beta hydroxy acid is commonly shortened to BHA. Actually, there’s only one acid in this class: Salicylic acid is derived from willow bark. In contrast to AHAs, it’s not water-soluble but oil-soluble. This means it can go deeper into the skin cutting through oils. It also is anti-inflammatory, making it an effective exfoliator for oils skin or clogged pores.
Lesser known are PHAs, or poly hydroxy acids. These have larger molecules than the AHAs. Think of AHAs as your big and strong plow horse and PHAs as your cute pony. With the bigger molecular size, PHAs can’t absorb so quickly into your skin making them less harsh. PHA can also act as an antioxidant and as added bonus bind moisture to your skin. Common examples are maltobionic and lactobionic acid. PHAs are a good choice when you’ve got dry, sensitive, or stressed skin.
Besides this group of chemical exfoliants, there are also other acids that can hydrate, lift age spots and other pigment problems, smooth wrinkles, reduce spots, or protect against free radical damage.
Can you combine acids?
First off, there’s no hard rule about mixing and combining products. Except that you have to listen to your skin and I’d also recommend that you should always consult a dermatologist so that you get the best blend for your skin.
Layering acids and products can be an awesome way to address several skin issues at once. This is because your skin is constantly changing and therefore its needs are also changed. So, it would be difficult to almost impossible for one single ingredient to address all you want to take care of. The following combos can be used together for enhanced effectiveness.
AHAs + BHAs
These are the classical exfoliators and complement each other, especially if you’re dealing with breakouts. You can think of them just like double-cleansing. You first use an oil-based cleanser to cut through oil, and that’s exactly the oil-soluble BHA. Then you follow with AHAs that are water-soluble. Both work together to clear any debris on your skin and in your pores.
The only downside is that this combo can lead to dry and irritated skin. If you want to be cautious, you can alternate when you use the one in the morning and the other in your nighttime routine.
Hyaluronic acid + AHAs/BHAs
Hyaluronic acid is very often used as a skin care ingredient because it’s a humectant. It draws water from the environment and binds it to your skin. Despite the “acid” part in its name, it’s not an exfoliant.
Since AHAs and BHAs can be drying, layering hyaluronic acid with them can help hydrate your skin and also decrease the risk of irritation. This is an excellent way to make sure that the acids won’t be too harsh on your skin.
Hyaluronic acid + vitamin A
Actually, it’s not vitamin A but retinoid acid, a derivative of the vitamin. It’s proven to be an excellent anti-ageing ingredient since it can reduce or even prevent the effect of sun damage such as dark spots and wrinkles. It enhances collagen production in the skin and can thus thicken your skin.
It works by stimulating cell turnover at the deep layers of your skin. But some people may find they can get flaky or dry skin as a result. So, pairing it with hyaluronic acid can help prevent dry skin. Both together are a power combo at improving your skin.
AHAs/BHAs/vitamin A + linoleic acid
Adding a facial oil when you’re using AHAs/BHAs/vitamin A will reduce the dryness that can come when using such acids. It will also add extra protection and nourishment, leaving your skin feeling soft and smooth.
Can you use water-soluble and oil-soluble products together?
Remember your science lesson in high school? Oil and water don’t mix. This is also why you add a facial Remember your science lesson in high school? Oil and water don’t mix. This is also why you add a facial oil near or at the end of your routine so that it forms a film on your skin and seals in all the moisture and goodness you’ve applied before. This film also prevents additional water-soluble products to absorb into your skin.
So, if you want to use both together, then you’d best start with the water-soluble products and finish with the oil-soluble ones.
Precaution and tips
Before you use any new product, but especially acids, it’s best to first do a small patch test. When you find your skin and the new product get along well, start with a low concentration, moving your way up as your skin builds tolerance.
Also, be mindful of what other active ingredients you use in your routine such as antioxidants. Mixing all together can increase the intensity of some acids which may lead to the infamous chemical burns associated with skin care acids. The other thing can also happen where ingredients cancel each other out.
Acids and the sun
Chemical exfoliators are known to make the skin more sensitive to the sun. If you’re using any kind of chemical exfoliator, it’s imperative to apply a high factor SPF and reapply every show hours.
Also, be mindful when you’re spending more time in the sun. In such cases, it’s better to use them only in the evening or even consider not using them at all during a holiday in the sun or at the beach.
Mixing and layering different acids can hook you. That’s because you can see noticeable results, and fast. Listen to your skin. Observe it closely, and when something is suddenly different, such as your skin is rougher or you suddenly get breakouts, that’s a clear sign your skin doesn’t like the new product or the acid. Stop using it immediately and see your derm.