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The Complete Guide to AHAs and BHAs in Skincare


You’ve probably seen AHAs/BHAs on your skincare bottle, but what are they, and what do they do? In this post, we’ll review everything you need to know about these important skincare ingredients. Find out where AHAs and BHAs come from, the effects they have, and the skin conditions they can treat.

What are AHAs and BHAs?

pipette dropper for skincare ingredients

AHAs stands for Alpha Hydroxy Acids, and BHAs stands for Beta Hydroxy Acids. These acids come from natural sources and have a range of skincare benefits. AHAs come from food, most commonly different types of fruit such as citrus fruits and grapes. BHAs used in skincare all come from one source, willow tree bark, and it’s often listed on products as salicylic acid. AHAs and BHAs can also be made synthetically. Lab-made hydroxy acids are molecularly identical to those that occur in nature.

Types of AHAs

There are eight types of alpha hydroxy acid used in skincare:

  • Lactic acid (from milk)
  • Glycolic acid (from sugar cane)
  • Citric acid (from citrus fruit)
  • Malic acid (from fruit)
  • Mandelic acid (from bitter almonds)
  • Tartaric acid (from grapes)
  • Hydroxycaproic acid (from royal jelly)
  • Hydroxycaprylic acid (from animals)

Each type of acid has a different skincare effect. Some improve hydration and smooth wrinkles and others speeding up shedding and tackling blocked pores. Using the right combination of AHAs and BHAs can help protect and nourish your skin.

Are AHAs and BHAs safe?

smiling woman touching her face

It might sound scary to put acid on your skin, but your skin is actually naturally acidic. All kinds of factors affect the acidity of skin, from the skincare products you use to pollutants in the air. Most people have skin that’s 4-5 pH, about the same as soda or black coffee. The acidity of our skin is important for its overall health, because it’s protected by an acid mantle. This is a beneficial combination of skin oils, nutrients, and amino acids.

The acid mantle defends our skin against bacteria and pollutants, and locks in moisture. It also protects the skin’s natural microbiome, which is the name for the bacteria, fungi, and viruses that call our skin home. While that might seem horrifying, these organisms are generally harmless to us, and are often beneficial. Your skin flora helps defend your skin against harmful microbes, and the whole ecosystem is as unique as you. Your environment, diet, genetics, and even your pets can affect the makeup of your microbiome.

What do AHAs do for your skin?

Each AHA has its own effects on your skin. Here’s what they are, where they come from, and the skincare benefits of using them.

Lactic acid

Lactic acid comes from lactose, a sugar molecule found in milk. The effect it has on your skin depends on the concentration used in skincare products. At 2% concentration, lactic acid helps to hydrate skin, while at 5-10% concentration its exfoliating effects kick in.

One of the two most commonly used AHAs in skincare (along with glycolic acid), lactic acid in higher concentrations can speed up desquamation (skin shedding), leading to a brighter, smoother complexion. It can even help reduce the appearance of acne scars and uneven pigmentation. It has a slightly larger molecule size than glycolic acid, so penetrates the skin more slowly, making it less likely to cause irritation.

Don’t worry if you’re lactose intolerant, you can still use lactic acid in skincare. That’s because lactic acid is the byproduct of a lactose-eating bacteria, and isn’t actually lactose. There are also vegan-friendly sources of lactic acid, including corn starch, beets, and other sugary foods.

Glycolic acid

Glycolic acid is derived from sugar cane, and is one of the most researched of all AHAs. We know that glycolic acid can penetrate through the upper layers of skin, helping to increase cell turnover and uncover the fresh new skin beneath. As with citric acid, the desquamating effects of glycolic acid also help clear pores, reducing blackheads and acne breakouts.

Another great benefit of using glycolic acid is as a hydrator, helping skin to retain moisture. In fact, glycolic acid will actually “teach” your skin to become better at holding water. This is great news for your complexion because hydrated skin is softer, firmer, and less wrinkled. And even better, glycolic acid stimulates fibroblasts to increase collagen production, strengthening the skin’s supportive matrix.

Often used in concentrations of 5% or higher, glycolic acid is well tolerated by almost all ages and skin types. It also has antioxidant and antibacterial properties that can help combat acne and skin damage. It also has the smallest molecule size of all AHAs, meaning it can penetrate deeper into the skin for more intense effects.

Citric acid

lemons and limes

Citric acid comes from citrus fruits such as lemons and limes. It has a pH around 2-3, which is usually slightly more acidic than your skin. Citric acid is often used as an exfoliant, breaking down the bonds holding dead cells together and boosting desquamation. This produces a clearer, brighter complexion. It can also help unclog pores.

You need a concentration of at least 10% to get the full exfoliating benefits of citric acid. However some people find it can irritate their skin because of its low pH. Sometimes citric acid is used in skincare formulations to lower the overall pH, rather than as an exfoliant.

Citric acid is also a powerful antioxidant, and can help protect your skin from free radical damage caused by pollution, tobacco smoke, and metabolic processes.

Malic acid

Malic acid is a fruit acid, and its name actually comes from the Latin word “malum,” meaning “apple,” which is the most common source of this ingredient. Like apples, malic acid has great antioxidant benefits for your skin, and as with other AHAs, malic acid increases skin shedding, leading to an improved complexion.

This acid has a larger molecule size than glycolic or lactic acid, which makes it harder for the skin to absorb. As such, it’s usually used in combination with other AHAs, at around 1-2% concentration, to get the full range of benefits from all the ingredients. Malic acid can also be used as a pH adjuster as it’s often more acidic than skin (pH 3-4) but not as acidic as citric acid.

Mandelic acid

Mandelic acid is derived from bitter almonds, and it’s one of the most effective AHAs when it comes to treating acne. That’s because it has amazing antibacterial properties that can even help tackle cystic acne. And of course it boosts skin shedding and improves skin tone, helping to treat signs of aging such as fine lines and wrinkles, as well as uneven pigmentation.

Mandelic acid has a larger molecular structure than other common AHAs such as glycolic acid, which means it absorbs slower into the skin. That’s great news for people who suffer from skin sensitivity, because the slow absorption gives their skin time to adjust, meaning less redness and irritation.

Tartaric acid

man holding a bunch of grapes

If you’ve ever eaten grapes, you’ve had tartaric acid before. This acid is used a lot in the food industry as a flavor enhancer, but in skincare it is prized for its keratolytic and astringent properties. Being keratoylic means it can treat conditions caused by overproduction of skin cells, such as warts and calluses. It’s often used in skincare products that target melasma, or uneven pigmentation.

Hydroxycaproic acid and Hydroxycaprylic acid

Hydroxycaprioic acid is found in royal jelly, an amazing substance made by bees to feed future queens (hence the name!). Hydroxycaprylic acid is a fatty acid produced by many animals. It’s less common to find hydroxycaprioic or hydroxycaprylic acid in skincare, although they both have many beneficial effects. Like other AHAs, they can be used to boost desquamation, increase hydration, and improve skin tone and texture. However other AHAs are more effective due to having a smaller molecule size, and are more likely to be used in skincare products.

How BHAs affect your skin

willow tree bark

While AHAs are very effective at increasing skin shedding, they can be irritating, especially for people with sensitive skin. BHAs are much better tolerated, even by people whose skin is prone to redness and irritation. That’s because BHAs are fat-soluble, which makes them very effective on oily skin because they are able to penetrate deeper into the skin. AHAs are water-soluble, and as a result work best on the skin’s outer layers.

Salicylic acid is derived from willow bark. It is the most frequently used BHA in skincare, and is a common ingredient in products designed to target acne. That’s because it works below the skin’s surface, where it can unclog pores and eliminate blackheads and breakouts. It also has anti-inflammatory and antibacterial properties, so it soothes skin, while still being an effective exfoliant.

AHAs and BHAs can be used together in the same product, which is great news for skincare fans. AHAs will take care of signs of aging such as fine lines and wrinkles, which BHAs control blackheads and acne breakouts.

Side effects of using AHAs and BHAs

The most common side effects people experience when using alpha or beta hydroxy acids are redness, dryness, and irritation. Often these symptoms improve as your skin gets used to the products. If you do experience these side effects, introduce AHAs and BHAs gradually to your routine. Consider using less product at first, only using products every other day, and removing products after 10 minutes until you build tolerance.

The other significant side effect is sun sensitivity. Because AHAs and BHAs help increase your rate of skin shedding, the new skin that is exposed is more sensitive to UV light. It’s important to always use sunscreen every day, but this is especially true when using skincare products containing AHAs/BHAs. The extra sensitivity can last up to 10 days, so continue to use sunscreen even if you discontinue use of products containing hydroxy acids.

How Qyral uses AHAs and BHAs

We love the effect that these acids have on skin. In order to minimize potential side effects, and target the results each customer wants, Qyral Accelerate Cellular Revitalizing Serum uses a customized blend of AHAs/BHAs to suit every individual. AHAs used in Qyral products include glycolic acid, lactic acid, malic acid, and mandelic acid. BHAs are included in the form of salicylic acid. Qyral formulations also use other plant acids, such as azelaic acid (from grains) and kojic acid (from fungi) to deliver a full range of skin-loving benefits.

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