- Lactic acid is the best exfoliating ingredient for dry, sensitive skin.
- Salicyclic acid is the best exfoliating ingredient for oily, acne-prone skin.
- These ingredients are examples of alpha-hydroxy and beta-hydroxy acids, which are considered the best chemical exfoliants, and are preferred over physical exfoliants.
- This article was medically reviewed by Debra Jaliman, MD, a board-certified dermatologist with a private practice in New York City.
- Visit Insider’s Health Reference library for more advice.
Exfoliation is the process of removing dead skin cells to reveal newer, healthier cells beneath. There are many benefits to regularly exfoliating your skin, from brightening your skin tone to reducing acne.
If done safely, exfoliation can be incorporated into anyone’s skincare routine, regardless of their skin type. Here are the best ingredients to look for when purchasing an exfoliating product.
Physical vs. chemical exfoliation
When choosing an exfoliating product, you must first decide between the two main types of exfoliants: physical and chemical. These two types use different methods to remove dead skin cells and which you choose could impact your skin’s appearance.
- Physical exfoliants are made of rough, gritty particles like ground walnut, apricot pits, or pumice crystals. These ingredients remove the top layer of your skin by physically rubbing against your skin’s surface to slough them off.
- Chemical exfoliants dissolve the links holding skin cells together. Once these bonds are broken, dead skin cells still clinging to your skin’s top layers can break off and be washed away. This process exposes healthy skin underneath and it also allows other skincare products to penetrate deeper into your skin layer.
Most dermatologists recommend chemical exfoliants, as physical exfoliants are more likely to scratch healthy skin and damage your skin barrier. Some people with very oily skin may be able to use physical exfoliants, but for most people, it’s best to opt for a chemical exfoliant.
There are two main categories of chemical exfoliants: alpha-hydroxy acids and beta-hydroxy acids. Below are some of the best exfoliating ingredients in each of these categories.
Alpha-hydroxy acids (AHAs)
Alpha-hydroxy acids are water-soluble acids found naturally in fruit and milk. Charlotte Birnbaum, MD, a dermatologist who practices at Spring Street Dermatology in New York City, says that these acids help our cells “turn over,” or replace themselves.
AHAs are primarily used for:
- Evening out skin tone
- Increasing collagen â€” the protein building block of your skin’s structure
- Reducing the appearance of wrinkles
AHA ingredients are often found in serums, face masks, chemical peels, and anti-ageing products. To reduce skin irritation, it is recommended that AHA concentrations for over-the-counter cosmetic products be limited to concentrations of less than 10%.
“Alpha-hydroxy acids can lead to dryness and irritation, so those with sensitive and dry skin should tread with caution using them,” Birnbaum says. Introduce AHAs slowly to your skincare routine, using products once or twice a week to see if redness or sensitivity occur, before gradually increasing your use.
The following are some of the best AHAs:
What it is and what it does: Lactic acid is a gentle exfoliant derived from sour (fermented) milk. Sometimes called sodium lactate, it is also an excellent moisturizer.Raman Madan, MD, Chief Dermatology Resident at Northwell Health in New York, says that he frequently recommends lactic acid to his patients because side effects tend to be mild or nonexistent.
Best suited for: Lactic acid works well on sensitive areas, like under your eyes. If your skin is prone to redness and irritation, formulations with lactic acid may work better for you than other AHAs.
What it is and what it does: Glycolic acid is a common AHA made from sugar cane, and has a small molecular weight. This means it easily penetrates the skin to exfoliate between skin cells.“We use glycolic acid for skin that tends to have a dull appearance. It’s a lot more powerful than lactic acid, so you need to be a bit more careful when using it,” says Madan.
Best suited for: Glycolic acid is great for acne-prone skin because it also has antimicrobial properties, which can kill acne-causing bacteria. However, because glycolic acid is stronger than lactic acid, avoid using it on sensitive areas, such as under your eyes. Madan also suggests you do not layer multiple skincare products with glycolic acid on the same day.
Citric and malic acids
What it is and what it does: Citric and malic acid are organic acids found in fruits and vegetables. Citric acid is derived from lemons, oranges, and limes and is actually considered both an AHA and a BHA. Malic acid is typically derived from apples. These acids exfoliate in similar ways to lactic and glycolic acid but add a bonus of powerful botanical antioxidants. The topical application of antioxidants can prevent ageing and dullness.
Best suited for: These types of acids can cause redness and inflammation, making them less than ideal if you have a skin condition like rosacea or acne. If you have sun-damaged skin or if your skin gets sunburned easily, using these acids to exfoliate might actually help by thickening the skin over time. Highly concentrated fruit-derived acids can be overpowering if they are left on your skin for more than a few minutes, so use sparingly.
Beta-hydroxy acids (BHAs)
Beta-hydroxy acids are oil-soluble acids that work as exfoliants.
BHAs work much like AHAs in that they help loosen bonds between dead skin cells so they can be cleared from your skin. However, unlike AHAs, BHAs can penetrate deeper layers of the skin, helping to loosen trapped bacteria and dirt from pores. This helps if you have frequent whiteheads or blackheads.
According to Birnbaum, beta-hydroxy acids can be used with alpha-hydroxy acids, but the two should be alternated every other day to avoid irritation. There is one common and effective BHA â€” salicylic acid.
What it is and what it does: Salicylic acid, which can be obtained from plant sources or manufactured in labs, is popular in acne-fighting skin-care products. That’s because it dissolves into our skin’s naturally produced oil, meaning it’s able to penetrate deeper. It’s also anti-inflammatory and tends to be less irritating than AHA ingredients.
Best suited for: According to both Birnbaum and Madan, salicylic acid is great for oilier, acne-prone skin types. Salicylic acid is popular in anti-ageing products, such as serums and creams. The Cosmetic Ingredient Review panel recommends that cosmetic products that contain the ingredient keep the concentration at 3% or under.
The bottom line
You can use exfoliating ingredients like AHAs and BHAs to help to dissolve dead skin cells and reveal healthy, younger skin cells underneath. These chemical exfoliants are widely recommended over physical exfoliants for optimal effectiveness and minimal health risks.
However, Madan cautions against layering different types of acids on your skin, as doing so may cause damage to your skin’s deeper layers. Avoid layering exfoliating ingredients, and cease use of any product if it causes side effects like chafing, inflammation, burning, or hives.
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