The Ultimate Guide to Skin Acids:
What Works for Your Skin Type

Are you using the right skin acids for your skincare routine? In this episode of The Skin Report, Dr. Simran Sethi breaks down the three key categories of skin acids—exfoliants, pigment reducers, and hydrating acids—and how they benefit different skin concerns. Whether you have acne-prone skin, melasma, or are looking to brighten your complexion, this episode will help you understand which acids work best for your needs. Plus, learn when to avoid using skin acids, especially after procedures like microneedling or laser treatments.

🔹 Key Topics Covered:

✔️ Exfoliating Acids (AHAs & BHAs like glycolic, salicylic, and mandelic acid)

✔️ Pigment-Reducing Acids (tranexamic acid, kojic acid, azelaic acid)

✔️ Hydrating Acids (hyaluronic acid and its role in skin barrier repair)

✔️ How to use acids for acne, hyperpigmentation, and normal skin

✔️ When to pause using acids after skin treatments or Accutane

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Hello everyone. Welcome back to The Skin Report. This month’s ingredient deep dive is skin acids. It’s not one ingredient, but it’s the whole category of skin acids. These are all good for your skin, depending on what they do and what kind of skin issue you have. So I’m going to help you understand and remember these in categories. We will talk about that first, then we’ll go into what skin conditions match or which skin acids work best for which skin conditions. And then finally, when you should avoid using skin acids in your skincare.

I’m Dr. Simran Sethi. I’m an internal medicine doctor who also specializes in medical aesthetics. Let’s get started.

So first I’m going to start by helping you remember acids in different categories. So when you’re looking at how to categorize the different acids used in skincare, I would say there are three broad categories. The first category, which probably has the most acids in it, is exfoliants, or chemical exfoliants. The second category is skin acids that help with depigmentation or skin lightening. And sometimes products that are in the exfoliant category are also used for skin brightening and lightening, but they do that in a different way, not by inhibiting pigment production, but by exfoliating. So exfoliation, reduction in pigmentation, and then the final category of acids are acids that help with hydration in the skin. Once you know which acids fall into these categories, you can then pick which group of acids is right for your skin condition.

So let’s start with the acids that fall in the chemical exfoliant category. Typically, these are alpha hydroxy acids, beta hydroxy acids, and those include glycolic acid, lactic, salicylic, mandelic acid. These are common ingredients that we find in cleansers, toners, and sometimes in serums, but their job is to exfoliate, and exfoliate dead skin cells that we all accumulate on our skin surface. And once you’ve exfoliated these, it will make you have less clogged pores. It also helps with hyperpigmentation, because that dead skin cell layer makes the skin look dull and a little pigmented.

The second category is skin acids that are used for reduction of pigmentation. Now, these brighten the skin by reducing the amount of pigment that the skin is producing, or your melanocytes are producing. So they are not exfoliating and brightening the skin, but actually reducing the amount of excess pigmentation.
The acids that fall in this category typically are tranexamic acid. Tranexamic acid is a more popular compound now because it’s popping up as a solution for hyperpigmentation, and it is not a hydroquinone, which I know that a lot of people are scared of using hydroquinone. I’ll talk about this in another video. Hydroquinone is something that can be used for reduction of pigmentation, but it has to be used carefully. But anyway, tranexamic acid is becoming a more popular way of addressing hyperpigmentation, and I think it works very, very well and it’s very safe.

The second acid that is a little lighter than tranexamic acid, but also used for reduction of hyperpigmentation is kojic acid. It’s derived from mushrooms. And then lighter than kojic acid, also for pigmentation reduction, is azelaic acid.

So these three acids are in the pigment reduction category and are in a lot of serums. Usually they’re not in cleansers, but more in serums or moisturizers.
Then finally, we have this category of acids that falls into hydration, or I should say rather hydration sealing. And there’s only one acid I’m going to mention here, and that is hyaluronic acid because it’s extremely common, it’s very effective, and it’s an excellent solution for literally every skin type.

Now that we’ve talked about the three different categories of skin acids, let’s talk about which skin acids work best for different skin issues. I’m going to start with acne. When people have acne, they have more inflammation. They also usually have a broken skin barrier because all of their acne breakouts are causing breaks in their skin, and also, many times, a lot of products they’re using are also drying their skin out, which all results in a broken skin barrier.

Finally, people with acne and a darker skin tone are very likely going to have post-inflammatory hyperpigmentation or dark spots because of their acne, in which case now not only do they have to address their broken skin barrier, but they also have to address dark spots.

People with acne actually can benefit from all three categories of skin acids, which would make you think, is that too many skin acids? Not really, because they all do different things in different mechanisms. So if you have acne, you should be on a skin acid that exfoliates, like salicylic acid. It gives you a nice chemical exfoliation, which is very important for acne-prone skin.

Second, you should be on something that reduces hyperpigmentation from post-inflammatory hyperpigmentation if you are a skin type four and greater with acne, and that means that you could consider a product that has really any of the acids that fall in that category, like tranexamic, azelaic, kojic acid.

Finally, because acne is an inflammatory condition, also with a broken skin barrier, you need hydration, in which case hyaluronic acid is an excellent solution for that.

So, acne-prone skin, consider all three categories of skincare acids.

Next, normal skin. So you have normal skin, you likely are going to have a little bit of sun damage, pigmentation, maybe fine lines. Well, in that case, consider something that gives you good protection of your moisturizer. And hyaluronic acid, our last hydrating acid category, is perfect for that. It can be easily paired in your daily regimen by either being in a moisturizer or applying on top of your moisturizer.

The next category that I see is a great candidate for skin acids, people with hyperpigmentation from melasma. Melasma is a condition where people are producing excess pigment. Mostly this is common in women who have a darker skin tone or skin type four or greater. And in melasma, usually women or people are looking for products that reduce pigmentation. Because of that, you are probably thinking, yes, I would obviously use the hyperpigmentation reduction category of acids. I want to mention this group separately because I find that they are better off avoiding the exfoliating category of acids because it can make their skin more sensitive, so they should avoid that, but include the pigment reduction category of acids, which include tranexamic acid, kojic acid, and they should definitely have a hyaluronic acid onboard because in melasma also, our skin does experience quite a bit of skin barrier damage.

We’ve talked about all the benefits of skin acids. Let’s talk about when should you not use them. There are some times when skin acids should be stopped just for a temporary period of time. And the only two categories that you should consider stopping are the acids that fall into the exfoliation category and acids that are in the depigmentation or pigmentation reduction category. And that is when you have any kind of skin procedure, microdermabrasion, chemical peel, microneedling, a laser treatment, or even laser hair removal. For all of these procedures, it’s best to stop any kind of skin acids that fall in the exfoliation category or pigment reduction category for at least one week.

The other category where it’s important to stop the exfoliation and pigment correction acids is if you are on Accutane. Accutane is an oral treatment for moderate to severe acne. And when people are on Accutane, their skin is very, very dry and sensitive and can stay like that for up to six months after stopping Accutane. So if you’re on Accutane and six months post Accutane, it is safe to use hyaluronic acid because it is very hydrating, but I would stop exfoliating acids or any pigment correcting acids.

We covered a lot about acids. I hope the different categories are now clear in your mind. If you have any comments or questions, please don’t hesitate to ask. Remember, subscribe, turn on your notifications so you can always stay informed about new content.