Exfoliating Acids in Skincare

Your guide to fresh and vibrant looking skin!

Photo by Coline Haslé on Unsplash

Growing up, I vividly remember the St Ives apricot scrub being a permanent fixture on our bathroom shelf. Fast forward to 2021 and there are tons of products — ranging from traditional oat/apricot/walnut scrubs to the so-called gentler face scrubs, washcloths and face sponges, to recent fads like electrical brushes. Many people dig into their kitchen pantries for scrubs. What’s common between them? They are all physical exfoliants that work by rubbing the skin to get rid of dirt and dead skin cells.

Exfoliation is extremely important but did you know that rubbing can damage the skin by causing ‘micro-tears’ (tiny) in its surface leading to a compromised skin barrier (the outermost layer) — making the skin dry, irritated, and sensitive. Not only is scrubbing abrasive, but it also only works on the skin’s surface.

So let me introduce you to a gentler, safer and more effective alternative — Exfoliating Acids. Gone are the days when acids were associated with strong and aggressive chemical peels done only by dermatologists. We’ve since discovered how to formulate them effectively at lower concentrations awarding them a coveted spot on our bathroom shelf.

What are exfoliating acids and how do they work?

Exfoliating acids are a class of chemical exfoliants that can penetrate deep through the skin layers. As opposed to physical scrubbing, acids work by dissolving the links (or bonds) that hold the dead skin cells together. This allows them to shed in even layers resulting in a smooth and refined skin texture.

What are the benefits of exfoliating acids?

According to research, the benefits of exfoliating acids extend way beyond just smooth skin. Exfoliating acids -

1. Reduce the appearance of fine lines and wrinkles — As we age, we produce less collagen (a protein required to keep the skin firm). In addition, daily UV exposure, pollution, and our lifestyle (stress, bad eating habits) damage healthy collagen. Exfoliating acids stimulate collagen production making the skin firmer and healthier.
2. Improve skin tone and texture — Acne, sun damage, hormonal changes can cause dark spots and hyperpigmentation. With regular exfoliation (i.e., constant shedding of the outermost layer of skin), the skin tone becomes more even revealing a brighter and radiant complexion.
3. Prevent acne by keeping the pores clean — When dead skin cells stay on the skin’s surface too long they tend to clog the pores which leads to blackheads, acne. By removing them with exfoliating acids, we prevent the pores from getting clogged, thus preventing acne.
4. Helps other skincare products penetrate deeper — Exfoliating acids make the skin more permeable by removing the dead skin cell barrier that prevents skin care products from penetrating deep into the skin and working their magic. This is why they are so important in a well-rounded skincare routine.
5. Boosts blood circulation in the skin — Exfoliating acids have anti-inflammatory properties that can help increase blood flow to the skin. This is particularly helpful for people with dull, pale complexions.

How many types of exfoliating acids are there?

They are classified into three types: AHA or alpha hydroxy acids, BHA or beta hydroxy acids, and PHA or polyhydroxy acids.

1. AHA — They are water-soluble acids derived from plants and fruits. Most common acids include glycolic, lactic, mandelic, and many more. Glycolic is the most well researched acid in this category and also the most commonly used. It has the lowest molecular size and hence most penetrative of all AHAs.
2. BHA — They are oil-soluble acids and work deeper beneath the skin to unclog pores, target blackheads, and reduce excess oil/sebum — perfect for oily and acne prone skin. When you hear BHA it usually refers to salicylic acid.
3. PHA — These are the new kids on the block and considered cousins of AHAs. They have a much larger molecular size than AHAs and BHAs and hence are less penetrative. This means less irritation and hence perfect for sensitive skin. The most common PHAs include gluconolactone, galactose, and lactobionic acid.

Which exfoliating acid is best for you?

1. Glycolic acid

• Ideal for aging skin, resistant skin
• Most potent and penetrative AHA; works on texture, hyperpigmentation, wrinkles
• Products

Paula’s Choice Resist Daily Smoothing Treatment with 5% AHA (Low Strength)

The Ordinary Glycolic Acid 7% Toning Solution (Mid Strength)

Paula’s Choice Resist Advanced Smoothing Treatment 10% AHA (High Strength)

2. Lactic acid

• Ideal for dry and dehydrated skin
• Less potent than Glycolic but is very hydrating; works on texture, hyperpigmentation, wrinkles
• Products

The Ordinary Lactic Acid 5% + HA (Low Strength)

The Ordinary Lactic Acid 10% + HA (High Strength)

3. Mandelic acid

• Ideal for sensitive skin
• Less potent than Glycolic and Lactic acid making it very gentle on skin; works on texture and hyperpigmentation
• Products

The Ordinary Mandelic Acid 10% + HA

Naturium Mandelic Topical Acid 12%

4. Salicylic acid

• Ideal for oily or acne-prone skin
• Helps with acne and blemishes, reduces enlarged pores, works on wrinkles
• Products

Paula’s Choice Skin Perfecting 2% BHA Liquid Exfoliant

5. PHA (gluconolactone, lactobionic acid)

• Ideal for super sensitive skin or conditions like eczema, rosacea
• Start with mandelic acid, if not well tolerated then switch to a PHA
• Products

Naturium PHA Topical Acid 12%

How to use exfoliating acids?

1. Begin early — Start in your teens or early 20s. A lot of teenagers suffer from oily skin and acne issues, or skin texture problems so AHAs and BHAs are perfect for them.
2. Go low and slow — Start with low concentrations once a week, and then build up to 2–3 nights a week. Don’t go beyond 10% on glycolic, 10% on lactic acid, 2% on salicylic, 12% on Mandelic and PHA. Also don’t forget to apply moisturizer after, this helps to maintain a healthy skin barrier.
3. Watch out for side effects — Since acids speed up cell turnover people who are prone to acne may notice a slight increase in acne activity (called purging). Nothing to worry about, this subsides within a few weeks of using acids. There are no other side effects so if your skin becomes red, irritated, or sensitive on touch you’ve over exfoliated and should stop. Go back to using just a moisturizer to repair the skin barrier.
4. Avoid conflicting skincare ingredients — Certain products such as benzoyl peroxide, vitamin C, retinol should not be paired with exfoliating acids as they make them less effective and also can irritate the skin. For instance, you can use a Vitamin C serum in the morning followed by SPF. In the evenings you can alternate between retinol and acids. Also read the ingredient labels carefully to check that you are not using multiple products containing acids.
5. Preferably use at night and don’t forget your SPF during the day — Acids can be used either in the morning or evening. Some AHAs (like Glycolic Acid) increase skin’s sensitivity to the sun so better if used in the evening. And don’t forget to wear a broad spectrum sunscreen during the day. You don’t want your new upper layer of skin to be damaged by sun exposure.

The bottom line….

Move over abrasive physical scrubs and say hello to exfoliating acids. They are an extremely important part of an effective and well-rounded skincare regimen since they work deeper in the skin layers to remove dead skin cells to reveal radiant, clear and younger looking skin. So don’t wait to start using them!