AHA vs BHA vs PHA: What’s The Difference?

Have you ever wondered what the difference is between AHA vs BHA vs PHA in skincare? If so, you’re not alone! In this article, we’ll break down the differences between these three types of acids and help you figure out which one is best for your skin type.

CeraVe Skin Renewing Nightly Exfoliating Treatment, Some By Mi AHA BHA PHA 30 Days Miracle Toner and Paula's Choice BHA Liquid Exfoliant

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AHA: Alpha Hydroxy Acid

The Inkey List Alpha Hydroxy Acid Serum and CeraVe Skin Renewing Nightly Exfoliating Treatment

AHA, the abbreviation for alpha hydroxy acid, is a water-soluble acid derived from natural sources, such as fruits and milk. AHAs are popular in skincare because they exfoliate the skin, which helps to remove dead skin cells and promote new cell growth. This can help improve the appearance of wrinkles, acne scars, and sun damage.

AHAs are formulated with pHs that are lower than that of normal skin, which is around 4.7. AHAs typically have a pH of about 3.0-4.0. This disrupts the hydrogen bonds that hold dead skin cells together and allows them to be easily removed by water when rinsed off.

NOTE: When using AHAs, BHAs, and PHAs, and for seven days after, it is important to wear a broad-spectrum sunscreen with an SPF of at least 30 since these exfoliating acids make your skin more sensitive to the sun’s UV rays.

Common AHAs in Skincare

Glycolic Acid

Glycolic Acid (derived from sugar cane): The most common AHA, glycolic acid, is a chemical exfoliant that increases collagen production for firmer-looking skin with a reduction in the appearance of fine lines and wrinkles. It increases skin thickness and has even been shown to be an effective treatment for mild to moderate acne.

Glycolic acid has the smallest molecule size of all AHAs and penetrates the skin most effectively. Unfortunately, it can also be the most irritating, so it usually isn’t the best choice for those with sensitive skin.

Glycolic acid increases cell turnover, which helps to disperse melanin (pigment) from the top layers of your skin. This results in a brighter, more even complexion and a reduction in the look of hyperpigmentation and dark spots.

Lactic Acid

Lactic Acid (derived from milk): Lactic acid is an AHA with a larger molecule size than glycolic acid, which means that it is gentler on the skin, making it a good choice for more sensitive skin. While it doesn’t penetrate the skin as deeply as glycolic acid, it also exfoliates the skin by increasing cell turnover.

Lactic acid offers anti-aging benefits as it reduces the look of lines and wrinkles, smoothes skin texture, and improves radiance.

Lactic acid hydrates the skin by binding water to the top layers of your skin. Lactic acid’s moisturizing properties make it an excellent choice for those with dull, dry skin.

Lactic acid also helps to remove melanin (pigment) from the top layers of your skin for a brighter, more even complexion and a reduction in the look of hyperpigmentation, age spots, and uneven skin tone.

Mandelic Acid

Mandelic Acid (derived from almonds): Mandelic acid is an AHA with a larger molecule size than glycolic acid or lactic acid, providing a gentler exfoliation. It is more suitable for those with sensitive skin.

This skincare acid also has antibacterial properties, which can be helpful for those with acne-prone skin. Mandelic acid also helps reduce post-inflammatory hyperpigmentation, which can result in those pesky post-acne scars and marks.

Malic Acid

Malic Acid (derived from apples and other fruits): Malic acid is a gentle AHA that helps to reduce dull, rough skin and discoloration. While less effective than other AHAs like glycolic acid and lactic acid, malic acid is often combined with other AHA exfoliants to improve their performance.

Citric Acid

Citric Acid (derived from citrus fruits): Citric acid is a mild AHA that exfoliates the skin and removes dead skin cells. Like malic acid, citric acid is less effective than other AHAs, so it is often mixed with other AHA exfoliants to enhance product performance. It is also used in cosmetic formulas to adjust pH levels.

Tartaric Acid

Tartaric Acid (derived from grapes): Tartaric acid is a weak AHA with antioxidant benefits that protect your skin from free radical damage. This AHA is often used in formulas with other exfoliating AHAs to help them maintain their pH levels.

BHA: Beta Hydroxy Acid

The Inkey List Beta Hydroxy Acid Serum and Paula's Choice BHA Liquid Exfoliant

BHA, the abbreviation for beta hydroxy acid, is a type of acid that is derived from natural sources, like willow bark and wintergreen leaves. BHAs work by exfoliating the skin, which helps to remove dead skin cells and promote new cell growth. This can help unclog pores, treat acne, and prevent future breakouts.

BHAs work similarly to AHAs, but they’re oil-soluble. BHAs exfoliate the skin’s surface like AHAs but reach into the pores, which AHAs do not. This makes BHAs ideal for those with oily or acne-prone skin.

BHAs penetrate your skin to dissolve oil and deeply cleanse your pores. They’re effective at treating blackheads and whiteheads because they can dissolve the sebum that’s trapped in the pore lining.

BHAs are usually gentle enough for most skin types, but keep in mind that if you’re new to acids or have a sensitive skin type, it’s a good idea to take things slowly at first or use them in smaller concentrations.

Salicylic Acid

Salicylic Acid: Salicylic acid is the most common BHA in skincare products. In over-the-counter products, a max 2% concentration will treat acne and even anti-aging skincare concerns like wrinkles and fine lines.

Salicylic acid sweeps away the build-up of skin cells inside pores which can lead to the development of blackheads and whiteheads.

Salicylic acid is also an anti-inflammatory, so it will help to reduce the redness and inflammation associated with acne and skin conditions like rosacea.

PHA: Poly Hydroxy Acid

The Inkey List PHA Toner and Naturium PHA Topical Acid 12%

PHA, the abbreviation for polyhydroxy acid, is a milder type of acid similar to AHAs and BHAs but is gentler on the skin. This makes it less likely to cause skin irritation or burning, which is why it’s a go-to option for people with sensitive skin.

PHAs are similar to AHAs, except their molecules have been altered slightly so that they don’t exfoliate as much as AHAs do. They still provide many of the same benefits, like anti-aging properties and moisturizing capabilities without being too harsh on your skin.

PHAs also exhibit antioxidant properties to help fight free radicals and reduce cell damage, making them a good choice if your skin shows visible signs of aging like wrinkles and hyperpigmentation.

PHAs can reduce glycation, a process where sugar molecules decrease skin elasticity and increase skin sallowness. In addition to those with sensitive skin, PHAs have also been found to be suitable for people who suffer from rosacea and atopic dermatitis.

Gluconolactone and Lactobionic Acid

Gluconolactone and its chemical relative lactobionic acid are PHAs that gently exfoliate the skin. They have moisturizing properties and can improve skin barrier function, which makes them appealing to those with dry, sensitive skin.

This 12-week clinical study compared products containing gluconolactone (PHA) to products containing glycolic acid (AHA). While both provided anti-aging benefits to the skin, the only statistically significant differences in anti-aging benefits where glycolic acid excelled were skin sallowness and pinch recoil. Not surprisingly, stinging, burning, and sensitivity were worse with the glycolic acid products.

This clinical study comparing gluconolactone to benzoyl peroxide in the treatment of acne found that gluconolactone and benzoyl peroxide both provided a significant effect on improving patients’ acne, but gluconolactone had fewer side effects.

AHA vs BHA vs PHA: Which Should You Use?

The Inkey List Alpha Hydroxy Acid, PHA Toner and Beta Hydroxy Acid

Balanced Skin: If you have balanced, blemish-free skin with a healthy moisture barrier and aren’t experiencing any active breakouts or irritation from your current skincare routine, then you could potentially benefit from both AHAs and BHAs.

Dry Skin: If you have dry skin, then a moisturizing AHA would be a good option for you to consider. You can also try adding in a BHA to help exfoliate your skin but keep in mind that if you have sensitive skin, BHA might irritate your skin, so it’s best to test things out slowly.

Combination Skin: If you have combination skin that leans dry but still produces an oily T-zone, BHA would be your best bet. You can start by using it only on the oily T-zone to help control oil production. Try a gentle exfoliating AHA on the rest of your face.

Oily Skin: If you have oily skin, a BHA like salicylic acid would be your best bet because it has oil-soluble properties that make it super effective at penetrating pores and treating acne. You can also use AHA in conjunction with BHA to help control oil production and prevent blackheads and whiteheads.

Acne-Prone Skin: If you have acne-prone skin with large pores, then BHA would be your best option. It effectively targets dead cells to leave your skin feeling smooth and your pores looking smaller. You can also use AHA like glycolic acid to increase cell turnover and decrease breakouts.

Sensitive Skin: If you have sensitive skin, you’ll want to start with a PHA because it’s the mildest of all the acids. PHAs are also known for their moisturizing properties, so they’re great for people who have dry or irritated skin.

AHA + BHA + PHA All In One Product

Some By Mi AHA BHA PHA 30 Days Miracle Toner

If you want to incorporate all three acids into your skincare routine in one easy-to-use product, consider Some By Mi AHA BHA PHA 30 Days Miracle Toner. This multi-acid toner contains an AHA, BHA, and PHA: citric acid, salicylic acid, and lactobionic acid plus papaya and witch hazel extracts to improve cell turnover and the look of dull skin.

Tea tree water extract supports clear and healthy skin and helps to soothe and refresh the skin. Adenosine and niacinamide work together to brighten and improve the appearance of fine lines.

The toner is alcohol-free, has a pH of 5.5, and is dermatologically tested for sensitive skin. This toner really keeps acne in check! Some By Mi also offers an AHA BHA PHA 30 Days Miracle Serum and AHA BHA PHA 30 Days Miracle Cream.

AHAs to Try

CeraVe Skin Renewing Nightly Exfoliation Treatment

CeraVe Skin Renewing Nightly Exfoliation Treatment

CeraVe Skin Renewing Nightly Exfoliation Treatment is a nightly treatment containing glycolic acid and lactic acid to exfoliate the skin, remove dead skin cells and reveal a brighter complexion.

This AHA treatment is enriched with three essential ceramides (1,3,6-ll) to help strengthen the skin’s natural barrier and lock in moisture. CeraVe’s proprietary MVE delivery system enables the ingredients to penetrate deep into the skin, providing all-day-long hydration.

This AHA treatment also contains licorice root extract to help lighten dark spots and even out skin tone. Hyaluronic acid binds water to the skin and prevents it from drying out.

The Inkey List Alpha Hydroxy Acid Serum

The Inkey List Alpha Hydroxy Acid Serum

The Inkey List Alpha Hydroxy Acid Serum contains 10% fruit acid, including lemon fruit extract (contains citric acid), orange fruit extract (contains citric acid and malic acid), and sugar maple extract (contains malic acid and tartaric acid).

These mild AHAs gently exfoliate the skin and can help improve skin texture, brightness, and skin tone.

This AHA serum also contains antioxidant bilberry fruit extract and sugar cane extract, a humectant that draws moisture to the skin. 1% low molecular weight hyaluronic acid hydrates, plumps, and moisturizes the skin.

BHAs to Try

The Inkey List Beta Hydroxy Acid Serum

The Inkey List Beta Hydroxy Acid Serum

The Inkey List Beta Hydroxy Acid Serum uses salicylic acid, a BHA that can help unclog pores, reduce inflammation, excess oil, blackheads, and fade acne scars. The BHA serum contains 2% salicylic acid to improve skin texture, help prevent breakouts and improve the look of enlarged pores.

1% hyaluronic acid is also included to prevent drying. As a humectant, it helps to draw in and retain moisture to keep the skin hydrated.

Paula’s Choice 2% BHA Liquid Exfoliant

Paula's Choice 2% BHA Liquid Exfoliant

Paula’s Choice 2% BHA Liquid Exfoliant is a best-selling salicylic acid treatment that can help control oily skin, unclog pores and fade acne scars. The exfoliant comes in a liquid form to easily penetrate the pores. It has a pH of 3.2-3.8, making it one of the most effective BHA products available.

This leave-on exfoliant clears out pores while helping to reduce the look of wrinkles and fine lines. It also contains Camellia Oleifera Leaf Extract, better known as green tea extract, which is rich in antioxidants that help fight free radicals and reduce inflammation.

PHAs to Try

The Inkey List PHA Toner

The Inkey List PHA Toner

The Inkey List PHA Toner is formulated with gluconolactone, a mild PHA exfoliant. It gently exfoliates the skin while moisturizing it, making it a good option for dry skin.

This PHA toner also contains 3% niacinamide, a multi-tasking ingredient known for its ability to reduce the appearance of pores, improve skin elasticity, strengthen the skin barrier, and brighten skin. Aloe barbadensis leaf juice calms the skin, making this toner perfect for sensitive skin.

Naturium PHA Topical Acid 12%

Naturium PHA Topical Acid 12%

Naturium PHA Topical Acid 12% is a gentle exfoliating serum formulated with lactobionic acid, mandelic acid, and gluconolactone to help even out skin tone and remove dead skin cells, smooth skin texture, and brighten the skin.

Lingonberry stem cells are rich in vitamins C and E and antioxidant polyphenols to help fight free radicals, improve the look of fine lines, wrinkles, dark spots, and improve skin hydration and roughness while slowing down signs of aging.

This PHA acid also contains 1% hyaluronic acid, which acts as a humectant to help keep the skin hydrated and plump. Perfect for dry, dull sensitive skin!

Final Thoughts on AHA vs BHA vs PHA

No matter your skin type or skin concern, there is an acid-based skincare product that provides chemical exfoliation to help your skin stay healthy and clear. You just have to find the one that’s right for your skin type.

Choose an AHA for exfoliation and brightening, a BHA for acne control and blackhead removal, and a PHA for gentle exfoliation without the irritation of stronger exfoliating acids.

Thanks for reading, and until next time, here’s to your good skin health!