11 Skincare Acids: What They Are, Benefits & How to Use Them

Are you someone who gets scared when they hear the word “acids” in skincare? Or are you the one who has adjusted to the idea and willing to know more about them? Whichever group you belong to, you’ll learn all about these skincare acids in this post.

With the evolution of skincare, you must have seen different acids everywhere. But what do these skincare acids mean? How do they benefit us? Which acid should you use in your skincare routine? If you are searching for an answer to these questions then this post is going to put an end to the search.

Here, I have explained what the most commonly used or heard of skincare acids do and how they benefit your skin. Welcome to the world of acids!

Different Types of Skincare Acids

1. Alpha Hydroxy Acid

Starting with the most popular skincare acid in the town – Alpha Hydroxy Acids, water-soluble acids that work on the skin’s surface. These chemical exfoliators take off dead skin cells & whiteheads, improve texture and brighten the skin tone.

They’re considered the best for dry, dehydrated skin, due to their ability to enhance natural moisturizing factors (NMFs) within the skin.

But any skin type will benefit from a well-formulated AHA. You should look out for products with a concentration between 4-10% and pH between 3-4.

It’s important to be more diligent with sunscreen as AHAs are known to increase skin’s sensitivity towards the sun.

There are a lot of AHAs but the following are the most heard of in the skincare industry:

Glycolic Acid – One of the most effective and well-researched AHA, glycolic acid has the smallest molecular size which enables deeper penetration. But that can also result in irritation among sensitive skin types.

Check out the review of The Ordinary 7% Glycolic Acid Solution, it’s the best for the price.

Lactic Acid – With a slightly larger molecular size, lactic acid exfoliates the skin with less irritation than glycolic acid. Most preferred by sensitive skin types or skincare beginners.

Mandelic Acid – With bigger molecular size (twice as large as Glycolic acid), mandelic acid is a lot less irritating and is considered best for people with very sensitive skin.

Citric Acid – It’s an AHA that is most commonly used in skincare products as a pH adjuster. It does have exfoliating properties but is not as commonly used. The other AHAs are considered gentler and are better researched.

The most commonly used AHAs are Glycolic acid and Lactic acid.

Everything is a waste if you’re not applying sunscreen daily.

2. Beta Hydroxy Acid

Beta hydroxy acids (BHAs) are chemical exfoliants that are oil-soluble and go deep inside the pores to unclog them.

The most commonly used BHA in skincare is Salicylic Acid. It’s perfect for people with combination to oily skin as it removes oil-buildup and dead skin cells that can cause acne.

Salicylic acid is an excellent ingredient for anyone with acne but it can be drying for people with dry skin. So it’s better for dry skin types to introduce this in a wash-off form, like a Salicylic Acid based cleanser.

The ideal pH range for it to work effectively is between 3-4 and you should look for 1-2% concentration.

My favourite BHA is The Ordinary Salicylic Acid 2% Solution, you can read all about it in the linked review post.

3. Poly Hydroxy Acids

Polyhydroxy acids are chemical exfoliants that are supposed to be as effective as AHAs but more compatible with sensitive skin types.

They work in a similar way as AHAs but don’t increase sun sensitivity. PHAs have larger molecular size, which inhibits deeper penetration, resulting in lesser irritation.

But are they as effective as AHAs? Even though the brands claim that PHAs are as effective, there’s still lesser evidence to support that as of now. Unless your skin is very sensitive, you should go for AHAs.

The PHAs you will find in your products are gluconolactone and lactobionic acid.

You can read my review on the By Wishtrend 2% Acid-duo Cleanser that has both BHA & PHA.

4. Azelaic Acid

Azelaic Acid can do whatever you want it to do! It’s a dicarboxylic acid that can be used as a gentle leave-on exfoliant that unclogs pores and refines skin texture. It also reduces redness and closed comedones.

You should reach out for 10% azelaic acid (the maximum permissible limit in OTC products) when you’re starting out. But over time you can increase the concentration and go for prescription products at concentration between 15-20%.

I’ve experienced great benefits from this ingredient during the time my skin was at its worst due to acne. You can read all about it in my review of The Ordinary Azelaic Acid 10% Suspension.

5. Tranexamic Acid

Another hot ingredient that works well for skin concerns like acne spots, melasma and sun damage. It’s still not commonly available in over the counter products but is a favorite among dermatologists.

It’s known to be as effective as Hydroquinone when used topically at a concentration between 2-5% with lesser irritation. A few brands that have tranexamic acid are Good Molecules, Skinceuticals, Murad and Peter Thomas Roth.

6. Kojic Acid

Kojic Acid is used in skincare products targeted for hyperpigmentation. It inhibits the activity of the enzyme that’s responsible for the production of melanin.

Some people also consider this to be a less irritating alternative to Hydroquinone but the general consensus is that the combination of both Kojic Acid and HQ gives the best results for skin issues like melasma.

You can find Kojic acid as one of the many ingredients in creams that claim to target dullness and hyperpigmentation. There are some Kojic Acid soaps available in the pharmacy and are recommended by dermatologists from time to time.

Not all acids are chemical exfoliators.

7. Ascorbic Acid

Ascorbic acid, also known as L-ascorbic acid, is the most well-researched form of Vitamin C. It is an antioxidant that fights free radicals, improves skin texture, evens out skin tone, reduces the appearance of fine lines and stimulates collagen.

The only problem is that this ingredient is unstable and gets oxidised easily. It’s best to keep it in a dark, cold area away from the sunlight and should ideally come in tinted bottles. They work the best at a low pH of 2.5-3.

The ideal Vitamin C serum should have Vitamin E and Ferulic Acid for added stability and antioxidant properties. A combination of all three, 15% L-Ascorbic Acid, 1% Vitamin E and 0.5% Ferulic Acid, can increase the efficacy of Vitamin C eight-fold.

Some of the brands to try out are Drunk Elephant, Timeless, Skinceuticals, Obagi and By Wishtrend.

8. Ferulic Acid

Ferulic acid is a plant-based antioxidant that fights free radicals but it’s mainly used in combination with Vitamin C and Vitamin E to enhance the stability of the formulation and is known to double the protection against sun damage.

9. Alpha Lipoic Acid

Alpha Lipoic Acid is a potent antioxidant that fights free radicals and improves skin texture. It helps to restore uneven skin tone and dullness.

The maximum concentration you should go for is 5% because it can be irritating at higher concentrations. The Ordinary has one if you wish to try this ingredient.

10. Retinoic Acid

Retinols/Retinoids are derived from Vitamin A and are the best anti-ageing ingredients anyone can use. They also improve elasticity, help with acne, clogged pores and PIH.

But they have a few side effects like drying, redness, peeling, etc. These become worse when you’re using Retin-A so it’s important to use them carefully to minimise irritation.

The skin can only process retinoic acid immediately and other forms like retinols have to be converted into retinoic acid by skin enzymes before the skin can use it.

There are several forms available – over-the-counter retinol (they convert to retinoic acid hence weaker), prescription-strength like tretinoin (these are retinoic acid so there’s no conversion, quite effective) and oral medication commonly known as Accutane.

Over-the-counter ones are weaker retinols but they still give great results. These are the ones you should try out if you’re a first-timer, look for the ones that are gentle and have low concentration. And use SPF because it makes your skin sensitive to the sun.

11. Hyaluronic Acid

Nowadays when people hear acids, all they can think of is exfoliation. But that’s not always true!

Hyaluronic Acid boosts skin’s moisture content and it can hold up to 1,000 times its own weight in water, which makes it an excellent hydrator for all skin types. 

It draws moisture from the surroundings and making the skin’s surface feel soft and hydrated. But it doesn’t provide extra hydration to the dry skin so make sure you apply hyaluronic acid on a damp face and lock it with an occlusive.

With hyaluronic acid serums, go for the ones that have other hydrating and soothing ingredients like Ceramides, Centella and/or Vitamin B5. I find that is better as compared to going for a standalone HA product.

How to choose the best acids for your skin?

You don’t have to get them all, pick one or two that sounds the closest to what your skin needs and start out with them.

If you’re a beginner and don’t have any of these:

I’d recommend an AHA or BHA depending on your skin type because everyone needs to exfoliate.

Look for toners/ serums that have Hyaluronic Acid.

Don’t exfoliate more than 3x a week.

You might experience purging initially.

There are a few brands that use a mix of multiple acids while maintaining an elegant and gentle formula. They should be the ones you should explore once you’ve figured out what works the best for you.

How to mix different acids in your skincare?

There’s a lot of confusion among people when it comes to using different ingredients in the same routine. Can you use Niacinamide in the same routine as Vitamin C? Retinol and Vitamin C? AHA & Retinol? AHA & BHA?

The answer to these questions is that it depends on YOU. Your skin’s threshold. Using an exfoliating acid in the same routine as Vitamin C or Retinol might result in skin irritation.

So if you’re someone just starting out and/or have sensitive skin then don’t use two acids (Ascorbic, BHA, AHA, Retinol) in the same routine.

Hyaluronic Acid can be used in the same routine as any other acid. It’s all about hit and trial to find what works the best for your skin.

I know it’s not the answer you were looking for, you wanted a list of ingredients that can be and can’t be mixed like the ones you see on Instagram & Pinterest. But it doesn’t work that way!

My only tip would be to keep it simple and once you find something that works for you stick to it.

It’s important to know that no matter how many great ingredients you use, it will all be of no use if you’re not protecting your skin against the sun.

My favourite sunscreen is Purito Centella Unscented SPF 50+, it is moisturising, non-irritating and has no white cast.

Which skincare acid are you a fan of?